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In recent, I am done compiling my teaching materials for the Fundamentals of Aircraft Manufacturing Management Process. I've studied some materials and currently doing theoretical research on Aircraft Manufacturing Management Process.
If anyone is interested to review my syllabus, lecture notes and PowerPoint slides then you can contact me.
I will be sharing my material and expecting/ requesting suggestions, comments, recommendations and your ideas to improve my lecture materials. Thanks in Advance.
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please send a short outline of your research and course material, Aircraft Manufacturing Management. I will give you a few comments, but may not have time to provide a detailed response.
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I'm simulating a 3D wing with winglet (on the tip) using ANSYS Fluent. I'm confused about how to calculate the area in reference values section. Please check the attached pictures of my wing model.
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For an entire wing, the reference area is usually the projected area from the top view. If you take just the tip my suggestion would be to parameterize the results for a certain range of the wing reference area (if the winglet has a defined dimension)
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Hello Network!
I’m currently working on a project related to the resilience of Air Navigation Service Providers (ANSP) to the outbreak of the COVID-19. The purpose of this research is to propose solutions for a sustainable way out of this global pandemic.
The main source of income of many ANSPs is the aeronautical charges, also known as ANSP charges, that are collected from airspace users in return for the services they received.
The COVID-19 has taught us that ANSPs cannot continue relying on Aeronautical charges only. Due to airspace restrictions since 2020, many airlines suspended their flights. This situation resulted in a lack of aircrafts in the airspace. ANSP charges depends on the traffic flow in the airspace. The more airlines fly, the more ANSPs can charge the airspace users. Therefore, in order to be resilient and be able to face future crisis, ANSPs should compulsorily find new business model that will strengthen the current one based on ANSP Charges.
What kind of new business model can we propose to ANSPs in order to diversify their sources of income?
This Network is the perfect place to ask this question and I hope that some specialists or experts will share their opinions.
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It is really difficult to suggest the business model to diversify their business during the Corona pandemic period.
These Air Navigation Service Providers are rendering their duty because of the air travellers movements from one place to another.
Even the existing business are getting deteriorated in all aspects. These people don't know except this services.
They can do some Cargo services which will support the Marketing dimensions.
There is a huge demands for consumable goods and services so that is the correct if way if concentrating during the pandemic period.
I don't have any idea or any business model suitable for them. Sorry.
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Is there a group of crucial and important UAV's parameters/features regardless of kind of mission (search missing people, disaster, evacuation, emergency deliveries, monitoring, fight a fire, training, saving trapped people, contamination, flying rescue cushion)? Or maybe every kind of mission has their own crucial parameters/features?
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The article is just click-bait; if somebody doesn't understand how the lift is created he/she haven't developed the most basic concepts of fluid dynamics. I'm trying to explain how the aerodynamic forces are generated around a body; excerpt from a course I'm working on:
"According to the kinetic molecular theory of gases ... static air exerts a pressure of about 101kPa on any object at sea level, created by the collisions between the object’s surfaces and air molecules ... this pressure changes when the air is not static but it moves around the object ... the random movement of the molecules changes, their random speed vectors gaining a component induced by the macroscopic air movement. ... This change of the random movement of the molecules is causing variations of pressure in the air volume, and acting over the object surfaces are creating forces, termed aerodynamic forces."
The article focuses on inability of common layman "lift theories" to account for the decrease of pressure and speed increase on the upper wing surface. I'm trying to correct this using some common sense.
Let's imagine a flat barn door (our "wing"), flying at an angle, through static air. Let's imagine the air molecules are un-moving grains of sand as a first approximation. In such a case the wing interacts only with the "molecules" that is able to hit, in the direct path of the wing. On the top region, the "wing" is not interacting with the "molecules", a void is created between the "wing" and the "molecules". This model is called "Newtonian sine-squared law of lift" and developed by - Newton in 1687. Interesting fact, this model is not at all accurate for normal flight, but it is accurate at hyper-sonic speeds and/or very low temperatures and pressures, such as space vehicles re-entry, as the molecular speeds are much lower than the aircraft speed.
Well, let's replace now the grains of sand with air molecules that are moving, according to the kinetic molecular theory of gases, at typical air at room conditions, the molecules are moving at about 500 m/s. A wing flying e.g. at 100 knots, about 50 m/s, is much slower. The void between the wing and the free stream is quickly filled by air molecules that are "pushed" in by elastic collisions with other air molecules. Since the air molecules are moving in the void in a global downward general direction, this has a macroscopic effect of increasing the airspeed. Since the total kinetic energy needs to be conserved, less molecular speed is available for collisions and that accounts for decreasing the pressure over the top of the wing. According to Bernoulli this is correct, as Bernoulli law is an energy conservation law, as applied to fluids. Since accelerating air downward is creating an upward lift force , the Newton's second law is also correct. So Bernoulli's and Newton's laws are actually the interpretation of the same physical phenomena.
Hopefully this short introduction dispels some misconceptions of how "no one can explain lift"
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Aerospace industry is based on innovative and path breaking technologies specifically in the field of Aeronautical design, development, materials, manufacturing processes, and quality. Most of the new technologies are developed and introduced in this industry due to its major role in fighters, drones, Satellite, etc.
The startups in high tech area take very high risks as the gestation period of investment is long and returns on investment are low. In addition, a few rejections of the design or product may lead to closure of startup. Despite of huge risk, entrepreneurs start startups.
This phenomenon is quite interesting but I find very less literature on it. I like to get the answers to my question "What is the motivation for startups in Aerospace industry?" despite of huge risk from the scholars of motivation, startup and aerospace fields.
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I think Aerospace industry is at a beginning of a complete transformation. A lot of tech startups are trying to capitalise on the premise that what is happened in the small consumer drones in the past years will continue on a bigger scale on manned aircraft, with the development of "urban air mobility" and "advanced air mobility". Startups like Joby, Lilium, raising USD 720M, and respectively USD 376M demonstrate plenty investor interest in the subject. Stunts like Zapata's Flyboard Air and Daedalus Mark 1 are capturing people's imagination, as well as plethora of manned multi-copter project that is bombarding media lately. A lot of pertinent people and organisations are thinking the technology is at the point where it permits creation of personal air vehicles to transition from everyday driving to flying. Everybody wants to be the first, but I think this is much more complicated than sticking a bunch of electric rotors to an air-frame.
A VTOL aircraft has conflicting requirements for the parameters that drives cruise and hovering performance: L/D drives the performance in cruise and that means large aspect ratio wings, low wetted area, careful design to minimise drag, and a small propeller size. Disk loading and no flow interference drives the hovering performance and that means large rotors and no wings. Actually, only 2 basic VTOL designs have evolved to 'life' over the last 50 years of experimenting and testing, and those are military aircraft. These are the V22- osprey - tilt-rotor, and harrier/F-35 - jet VTOL, the military specification aspect to perform the mission are the reason of their success, the economic cost is secondary.
The civilian marked is driven by economics, and as long that the aircraft design compromises too much, it will never be a viable option. Some people believe that the electric propulsion solves the problem, because of the high inherent efficiency, distributed propulsion and other effects, but a hidden aspect that kills the efficiency is the aerodynamics of VTOL. If the aerodynamics is not right, you end up with an inefficient aircraft, that only exacerbates the unwanted characteristics of electric propulsion - the weight and low specific energy of current batteries. I don't think the hybrid power generation, as hydrogen fuel cells, are the right solution either, it just increases the weight and complexity with marginal gains. It's much better to concentrate on the weakest link in the whole chain and that is the aerodynamics of VTOL flight. Current battery technology are good enough to develop today aircraft with ranges to cover average commuting distances.
I'm not a fan of UBER's proposals either. They want 6-8 passenger "air-taxi" style VTOL aircraft, flying between city vertiport hubs, so they can capitalise on the whole route, from driving to the vertiport, flight to next vertiport, drive to final destination. My opinion is that from the passenger perspective is much better to fly directly "door to door" with smaller personal aircraft, you eliminate driving, hub transition, boarding and waiting times. Not to mention you eliminate huge vertiport hub infrastructure that needs to be developed and maintained. Small sized aircraft can land in small spaces, why not develop standards for small vertipads that can be installed everywhere, from personal driveways to supermarkets and local grocery stores.
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Hi. Can anyone could recommend an aeronautical / aviation conferences to attend in 2020 in Europe; particularly for fluid mechanics and applied aerodynamics. Thanks!
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Dear collegues, i'm looking for informations about a topic that i must presente in our class, it's about hybrid propulsion in aeronautics, if you have ideas, documents, web sites, PDF documents that can help me .
Thank you very much.
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Refer this article. Its most read
Brelje BJ, Martins JR. Electric, hybrid, and turboelectric fixed-wing aircraft: A review of concepts, models, and design approaches. Progress in Aerospace Sciences. 2019 Jan 1;104:1-9.
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Karpp RR. Prog Astronaut Aeronaut 1993;155:223.
Above is the information shown in the reference part in the paper I am reading now. I even couldn't find the name of this reference. The content in it should include a table or something else that introduce parameters in Mie-Gruneisen EOS model.
Thanks a lot.
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Is this what you are looking for? https://doi.org/10.2514/5.9781563479854.0039.0049
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Hello,
How is your day? I hope you are very well.
Health and Peace!
My name is Marizene Nonato da Silva. Nice to meet you.
I am a master student at the Institute of Aeronautical Technology (ITA) - São José dos Campos in Brazil.
I research this my theme of study now: Space Elevator.
Thank you for taking your time in to answer my ask.
Respectfully,
Marizene Nonato da Silva -
Master's student in the Space Science and Technology Program at ITA
Research Line: Engineering and Space Technology Management
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You can't build an elevator to the ISS at 400km, because at this altitude the orbital rotation speed is not the same as the earth rotation speed. Furthermore, the ISS orbit is not on the equatorial plane.
The idea of Space elevator is conceivable only in the equatorial plane and does not really make sense elsewhere.
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A student of materials engineering & structures, I would like to have some guidance in finding interesting master thesis topics in the mentioned field! Something that can be done with motorcycle OEMs? Something similar in Aeronautical industry would also be interesting. Kindly help.
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There is a big drive into lightweight materials i.e. composites, aluminium, etc. As Emmanuel has mentioned additive manufacturing is big on the agenda. The lightweighting is mainly supporting hybrid and electric powertrains. These powertains are heavy, so to reduce weight and increase range the industry is looking at lightweighting.
I suppose with motorcycles it will be similar. I've seen a motorcycle manufacturers also developing electric powertrains. So again, lightweight materials would be good. Most people tend to concentrate on the frame. However, how about reducing the weight of the engine (if keeping internal combustion) and look at reducing the weight of components such as suspension, etc.
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The ability to track aircraft in flight has often been overlooked due to the cost implications but how possible is it?
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We have developed EFIS/GNSS aircraft satellite tracking system that can satisfy ICAO GADSS . http://www.sciencepubco.com/index.php/ijet/article/view/21320 .
We (UPNM/Worldgate) through university industry collaboration shall try to certify it as TSO so that it can be fitted to civil aircraft. .The sensors consist of 9 axis (accelorometers /gro/magnetometers) and GNSS(3D) that are telemetry to servers via iridium/gsm and short range IT devices via WiFi. Its not only provide tracking capability but also EFIS data except we don't install air speed since we want to be independent of aircraft system.
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I would love to know what human factors you are considering for this research project and where you currently stand in the research of this topic. I believe that this topic would be beneficial to the study that I am working to complete as part of my capstone project from my Bachelors Degree in Aeronautics through Embry-Riddle Aeronautical University.
Thanks
Daniel Brooks
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Crew Resource Management Concept is relevant for proactive safety awareness in critical situation management team communications scenario. This covers human factors of culture and individual team member power bases interaction in crisis management teaming. The opposite of CRM is 'Captainitis' , where the leader flies on using his /her own human error fallability only , and ignoring crew advice, help and oops alerts from crew. Detailing for that CRM was once included in training syllabus on International Helicopter Association ( IHA) (Canada) website for pilots and flight crew training and audit in low flying in the wire risk context . I would suggest a maintenance team in crisis is an extended flight crew when maintenance impacts on mission . CRM usually helps /applies in all human crew critical incident situations ?
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b) start from mobile platform - in Poland: http://s4t.com.pl/#
about other:
c) Delivery of medicines, blood, defibrillators - in Poland: https://www.airvein.io/, https://www.linkedin.com/company/airvein-sp.-z-o.o.?originalSubdomain=pl,
d) Delivery of life jacket, pod, raft
f) spraying anti fire chemical compounds
h) New Futuristic Massive Firefighting Drones, https://www.youtube.com/watch?v=GL8L2Y2RtWY
j) Detecting Wifi signals from smartphones of trapped people, https://www.youtube.com/watch?v=7ysg-m7kV14
k) Dropping a fire-blanket???
l) Fire ignitions
FlamethrowersTF-19 WASP Flamethrower Drone Attachment , https://throwflame.com/products/flamethrower-drone-kit/
n) Launches Autonomous Drone,
o) Charging Pad
p) Wireless charging
PS.
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Surveying burn areas, fire movement, damage/impact. Looking for survivors.
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Is it correct to use a term "drone/UAV special for fire service/fire brigades"? Or are there only a adaptations/modifications of available models (like adaptations of Matrice - see https://www.dslrpros.com/inspire-1-first-responder-thermal-kit.html https://www.rmus.com/collections/police-fire-search-and-rescue-drones)?
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It depends a bit on what aspect of the fire-fighting you focus:
- For the assessment phase, typically quite standard UAV's are used. These are typically sturdier models that feature a short deployment time and are often also used by civil protection, police, ...
- For the fire-extinguishing phase, purpose-built solutions do exist, e.g.: https://www.aerones.com/eng/firefighting_drone/
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Am in final stages of my Phd in Supersonic Aerodynamics . I would like to apply for post doctoral position in the field of Aeronautical in reputed universities. Can anyone pls guide me
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Check cfdonline, linkedin and researchgate
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I need to calculate the forces caused by vortex shedding(or vortex induced vibrations) on a tapered cantilever structure under wind loading.
I did some reading and some researchers suggests to calculate the response using some empirical equations to include the motion induced forces due to lock in and negative damping as I understood.
Your advice and suggestions will be appreciated.
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I would look on line for the Strouhal number of similar structures at similar Reynolds numbers to see what is already been done. When in doubt 0.22 is a good first guess at the Strouhal number. From there I would set up an excel spreadsheet with different heights above the base plane, then do a 1/7th power law for the boundary layer effect and calculate the wind velocity in 10 or so different points up the height. From there you should be able to get the vortex shedding frequency as a function of wind speed and height to compare to your structural resonances. Figuring out the unsteady lift force is more problematic from first principles but I bet there is a lot out there in the published technical literature. Good luck
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Hello.
I am trying to find metals/alloys apart from titanium which are not harmful for the jet engine cooling systems. I know that jet engine lubrication oils are usually "neopentyl plyol esters", but I have not been able to find any information on materials apart from titanium that can withstand such lubrication oils. Any book or article sources that gives information will be helpful. I have not been able to find much information probably because my background is in mechanical/aeronautical engineering and the searches are limited to general terminology. In addition to this, my current project is fairly interdisclipinary and requires intermediate to advanced knowledge of chemistry.
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Hello Mr Ishan, You will have to specify the material and then search for compatible lubrication oil that are non corrosive for that material. Usually the material used is steel alloyed with molybdenum, Magnesium, copper aluminium etc, in many bearings. I have worked with OX-27 oil on APU engines, which have to be drained for engine preservation, and we use OM-11 as the preservative oil. If you see bearings used in aerospace applications, many bearings are made from vacuum-melt 52100 or VIM-VAR M-50 steel and are normally manufactured to ANSI/ABMA
tolerance class 5 (ISO class 5), with high-strength machined
cages. You can refer NASA TM 102529 on steel bearings used in aerospace applications. Hope this information is useful.
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As usually the trend is a Courant number (CFL no) can only be used for a Transient( Unsteady) flow condition.
Thank you in Advance.
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The short answer is Fluent uses the CFL number to compute the time step (even for steady flows). A more detailed explanation follows...
The coupled set of governing equations is discretized in time for both steady and unsteady (transient) calculations. In the steady case, it is assumed that time marching proceeds until a steady-state solution is reached. Temporal discretization of the coupled equations is accomplished by either an implicit or an explicit time-marching algorithm. In the Explicit Formulation the time step is computed from the Courant-Friedrichs-Lewy (CFL) condition. The time step is a function of: the cell volume, the cell face area, and the maximum of local eigenvalues.
Here is some additional information straight from the theory guide (Fluent Version 6) in the section: Steady-State Flow Solution Methods.
For steady-state solutions, convergence acceleration of the explicit formulation can be achieved with the use of local time stepping, residual smoothing, and full-approximation storage multigrid.
Local time stepping is a method by which the solution at each control volume is advanced in time with respect to the cell time step, defined by the local stability limit of the time-stepping scheme.
Residual smoothing, on the other hand, increases the bound of stability limits of the time-stepping scheme and hence allows for the use of a larger CFL value to achieve fast convergence.
The convergence rate of the explicit scheme can be accelerated through use of the full-approximation storage (FAS) multigrid method.
By default, FLUENT uses a 3-stage Runge-Kutta scheme for steady-state flows that use the density-based explicit solver.
Hope this helps!
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eagerly waiting for response
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Dear Vikas Kumar, thanks for your interest on our research. I think there are mainly three kind of methods for controlling or suppressing the edge chipping in RUM of brittle materials. 1. Adding additional support at the hole exit. 2. Processing parameters optimization (spindle speed, feedrate, ultrasonic amplitude). 3. Tool design, such as reducing tool wall thickness, or using the low-damage tool which can gradually reduce cutting force at hole exit. More detailed information can be found from our paper entitled ‘damage formation and suppression in rotary ultrasonic machining of hard and brittle materials: A critical review’ you can find it on the journal ‘Ceramic International’.
Regards.
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Recently, a friend of mine working on a different project has waved me into his office. It turned out that he wanted to visualise the orbit of one of space probes, and the orbital elements he had were not pretty: in fact, they resembled a sawtooth in one of the axes (and were seemed normal in the other two). He asked for my suggestion regarding fixing the flight path for the presentation purposes; I typed up a quick and dirty implementation of a moving average smoothing algorithm that was enough for a last-minute fix.
After walking home from my work I first spent a couple of minutes thinking whether I should have applied a different approach (such as fitting polynomials or local regression, or whatever jumped to my mind at the moment), but moments later I realised I have no idea why do the data look that way. Any explanation for such a sawtooth for being there? It is too regular to look like constant engine corrections. Do any of you have a clue?
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Tomasz, the observation of this signature in the absence of pertubations of the other axes strikes me too. If there had been gravitational forces - or even regular engine corrections, you might have expected pertubations on at least two axes. Therefore I strongly suppose some artifacts in the measured orbital data.
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This works has been made within a project with the CNES (French National Center for Space Studies, during my studies in aeronautic engineer high school), within the project for the study of the sizing of the lauching pad of Ariane 5 project sattelite launcher.
I have made a lot of research to find if this theroem was known or not ?
I had never never found a reference ? May you help me please.
Before the theorem statement, just few recall :
1/ The aerodynamic drag is given (within special domain) traditionaly by : 1/2 Cx ro S v^2
    (ro being the air density, v the velocity (relative to air flow), and Cx the so called penetration coefficient)
    The term of interest in the problem is the S, which is called the "master couple, french traduction of the term used in french" which represents the projection surface of the body on a plan perpendicular to it's trajectory vector.
2/ The theorem I have demonstrated is the following statement :
   " The average master couple for any convex body over all orientations (then integrated over unit sphere, for projection axis) is equal to the "Exterior Surface of the body" divided by 4. "
[this is an evidence for the particular case of the sphere : 4 pi R2 / 4 = pi R2 projected surface equal everywhere]
I know that at the epoch, these formula was used by persons as an heurisic ?
3/ But my definitive questions are :
Is this theorem relevant or not ?
Is it an obvious corollary of convex mathematics ?
(which is from my point of view certainly the case) ?
PS = I have also demonstrated the exact formula for only one particular non convex body (in fact a surface, but this is just a question of factor 2) which is an angular part of a section of a cylinder). This is not really difficult but hardly analysis computational !
and an approximation formula for non convex body (but I do not realy know the quality)
and other few relative theorems (like the result for the union of two convex body creating another convex body)
Thx in advance for any kind of answer ?
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Dear Herve, I'am interested on your topic: do you have a paper/document on theorem's proof? Thanks.  Gianluca
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I'm designing an aeroelastic model to test in wind tunnel.
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I need to design an aeroelastic model of a tensile structure (hyperbolic paraboloid cables net and membrane). The natural frequency, damper and mass are fixed using the aeroelastic scaling laws. These laws fixes frequency ratio, damping or wind speed ratio. However, generally, they are used for buildings very different from flexible roofs.
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hello
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سلام.متوجه سوالتون نشدم
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There are :*
Aeronautics
Biomedical
Defence
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By compacting pressure and sintering temperature , we can obtain different alloys made from Ti  with addation metal such as Ni , zro2 ..etc .this alloys is used as a biomaterials such as stent in catheter or dental post .
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What Knowledge Management System Software is being used by major Aeronautics Industries of the world ?
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I am more familiar with KM and KBE concepts that are being used in Aeronautics Industries for product Design and Development. Here are few papers/ application examples. Take a look.
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Would anyone be able to explain to me how I can calculate the Reynolds number for a HAWT when I have the freestream velocity, power coefficient and tip speed ratio values. I'm trying to figure out the axial and tangential induction factors.
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Hallo Jeremiah,
Normally, the Re is the tip Re in the wind turbine simualtions therefore,
Re = (Roh*tip_Speed*L)/meu
Roh and meu are the air properties at the inlet
L is the blade chord at the tip
tip_Speed = sqrt(Uinf^2+(omega*R)^2)
where Uinf : is the free stream velocity   (known)
from the tip-speed ratio you can calculate the (omega*R)
(omega*R)=tip-speed ratio * Uinf
I hope that might help you
Best regards
Mohamed
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Hi
I'm conducting a literature review on Formation Flying. While there are numerous studies and surveys on the subject, I have not been able to find a well-structured concept map on the general FF research framework. Any recommendation is greatly appreciated.
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Dear Sir
Thank you very much
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Hello,
I have a project about finding Cd and Cl for NACA 2415 for different angle of atacks.
I have a problem. The flow appears to be reverse and i hhave negatives coefficients of drag. Why this happens? 
Boundary conditions at outlet is zero pressure, and I change the direction of the flow. Re 600000.
Thanks
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Thanks for your reply. It seems that the problem was a x,y component of flow direction.  I rotated the compudational domain for each degree i  wanted to study and at the boundary conditions, i inserted at the inlet, velocity in x direction only, (which is vertical  at the inlet). See below my results. 
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cleaned
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Hi Paulo,
You might find the following two references helpful.
Rogalski, A., & Chrzanowski, K. (2014). Infrared Devices and techniques (revision). Metrology and Measurement Systems, 21(4), 565-618.
McManamon, P. F., Watson, E. A., & Eismann, M. T. (1998, March). Suggestions for low cost multifunction sensing. In Aerospace Conference, 1998 IEEE (Vol. 1, pp. 283-307). IEEE.
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what are the necessary things i have to take into account, while concentrating 1/2+ kg load...?
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I agree with Naceur's input on specifics - looking, for example, at HALE type fixed wing UAV, 1/2kg seems no challenge at all...
Nevertheless, in general, I would focus on three main aspects to derrive at load carrying capabilities:
- size (larger lifting surfaces whether as wing or rotor usually translate into more lifting capability)
- speed (higher speeds allow higher lift production, all other parameters considered fixed; again, in general, it doesn't matter whether fwd speed of a wing or rotational speed of a rotor)
- propulsion (the two points above directly will affect drag which in turn will require excess thrust to overcome)
Hope that helps at the conceptual level
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When designing the control systems, I always confused about how to get the bandwidth of the systems. Nearly all the textbooks says like :"In the systems where the low-frequency magnitude is 0 dB on the Bode diagram, the bandwidth is measured at -3dB frequency." But almost all of the systems I meet in practice do not satisfy the conditions that the low-frequency magnitude is 0 dB on the Bode diagram. The low-frequency is always above or lower than 0 dB. What's more, the open-loop cut-off frequency on the Bode diagram is always connected with the bandwidth of close-loop. In this situations, if there is a cut-off frequency, the low-frequency will not be 0dB.
In wiki, it says the bandwidth is the range of frequency which is less than 3dB below the maximum value. While in a ppt created by Dr Grant Covic for paper: Systems & Control 1988: Document 3 of 3, it says:"Some type 0 systems do not have 0dB low frequency gains, hence the bandwidth is normally taken over the frequency range that has gain > –3dB above the designed passband gain." So more confused. So I want to ask your opinions of how to calculate the bandwidth when the low-frequency is above or lower than 0 dB? And if there are some books or articles talking about this? Thank you very much for your help.
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For your maximum value (for example 34 dB or 15 dB, or -5 dB) you must define the value 0dB. From this maximum value (34dB, 15dB, -5dB) then decrease value 3 dB and you will get the value on level -3 dB, it means (31dB or 12dB or -8dB). On these values (31dB or 12dB or -8dB) then you define searched frequency bandwidth.
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Is there a new cognitive task analysis in Phases of flight for pilot?
Please, send me.
Thanks, for your attention
“Phases of flight” means: Pre-flight, Pre-departure, Gate Departure, Taxi-out, Take-off, Terminal Area Departure, Climb, Cruise, Descent, Terminal Area Arrival, Final Approach, Landing and Rollout, Taxi-in, Parking and Post-flight.
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I need this data for my thesis, but I can not find it anywhere. There are still some books to order, but I am rather a pessimist.
This postion looks intresting but I can not find it anywhere. Maybe somebody is able to tell me if required data is there?
Althaus, D., 'ProfilePolaren Fur den Modellflug (Windkanalmessungen an
Profile im Kritischen Reynoldszahlbereich)', [Model airfoil polars
(Wind tunnel measurements of airfoils at critical Reynolds numbers)],
Institut Fur Aerodynamik u. Gasdynamik der Universitat Stuttgart.
Neckar-Verlag, Postfach 1820, 7730 Villingen-Schwenningen, Germany, 1980.
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Dear Mr Wild,
your answer is very valuable, thank you, I will stick to it.
Kind regards!
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Hello, im trying to simulate the flow around the Ahmed body and i want to plot the velocity profiles graphs that many papers have but i can't understand how to do that. Can anyone guide me into that? I should mention that i am using Fluent for my simulation.
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Graphs or contours? 
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especially wide aspect ratio 
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If the aspect ratio is low then secondary loss and tip leakage loss have a greater percentage effect and the efficiency falls. However the low aspect ratio blades are relatively stiff and forced response and flutter are less likely. With high aspect ratio the blades become floppy and their resonant frequencies fall flutter is more likely to occur. Also high aspect ratio blades for te same duty as low aspect ratio blades have much smaller aerofoils and therefore Reynolds number. This leads to thicker boundary layers and tends to lower efficiency. The number of leading edges and their blockage is changing too. So high aspect ratio leads to lower efficiency and more vibration. Too low aspect ratio has low efficiency and requires greater axial gaps to avoid forced resonse issue.
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i have an ODB of some thousand elements. i want to copy some elements to new empty odb and run it again to get results for that elements. is that possible ?
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Hi Arun,
By saying ODB, I assume you are using Abaqus to generate your results as the ODB file. If so, then you have the functionality to import back the ODB as a new model. (See first picture) You can then edit the elements.
Also, you have the option to import them part-by-part in which case you could import deformed configurations as well. (See second picture). Once you've done it, you can again remove or add elements as you wish.
I hope this helps! There is a blog post at Intrinsys, listing the part import functionalities of Abaqus here: http://www.intrinsys.com/blog/2016/importing-parts-into-abaqus-cae
If you are looking for more help or tips/tricks regarding Abaqus and CATIA, look around the blog, you will find a lot of useful information!
Best regards,
David
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Real aircraft is too large and when i use similar parameters then, i can't simulate the flow for large velocities in wind tunnel. Is there a way to simulate high velocities in wind tunnel.
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Thanks, John, for the remark on pressurized and/or cryogenic testing, since this is the only way to get Mach and Reynolds number similarity for down scaled models - unless you change (theoretically) the flow medium (e.g. a water tunnel gives you easily Reynolds number similarity - but no Mach similarity except for real incompressible flows at M<<0.1).
Nevertheless, if you are limited by the available wind tunnel facility, it is probably more important to match the Mach number similarity and accept that you will measure higher friction forces (drag) than to be expected for the real aircraft. There are some extrapolation methods around (see some AGARD reports on wind tunnel testing) to estimate the drag variation. When it comes to flow separation the situation gest more complicated, although proper transition tripping will help to eliminate low Reynolds number artefacts. Anyhow, these measurements will not give you absolutely accurate values, but e.g. to compare designs it is mostly sufficient.
One remark to the answers above:
@Aziz: your comment may hold for bodies where the drag is mostly related to pressure drag only. For bodies where the drag is dominated by friction forces, your comment that CD doesn't significantly change between Re=1000 or Re = 10 mil. is definitely wrong.
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When no of impact on the laminate increases, saturation in water absorption of composite laminate will come earlier or take long time?
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I could not get how the impact is made. One reaason for lesser time indicates damage to the structure opening higher no. of defect sites or longer when the impact compresses the pores and allow only slow ingress requiring long time.
Anyway, a detailed picture will be more helpful to answer better.
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Do you know of any unstable aircrfat used for commercial operation including cargo?
Do you think it is a good idea to use such aircraft for commercial operation? Provided the higher payload it provides. The idea could be more feasible for cargo operation.
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MD11 and F117
but the heavier plane needs more accurate, complex and cost fortune safe operation system
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I like to know if any experiments carried out on NLF airfoil with ice accretion models.
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Dear Sir
I am attaching a paper.
with regards
Y D Dwivedi
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I have used YSZ-YSZ/Al2O3 double-layer TBC for my Rocket nozzle.
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I am researching in the same issue
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Suppose, a simplified model of the roll dynamics of an aircraft, which is represented by xdot(t) = A x(t) + B u(t), where the states are (phi, p) and the u is the aileron command **(neglecting the dutch-roll mode).
Due the fact that, the controller contains an integral term, the system dynamics is augmented to contain the state related to the integral of the error signal. Let's call it of Tau(t). Then, we have [xdot Tau_dot] = A_aug x_aug(t) + B_aug u(t).
So, the control law is given by u(t) = - K x_aug + K(1) Phi(ref), where K is the static gain of the controller. Which we can "interpreted" as K = [Kp Kd Ki] = [Proportional, Derivative , Integral] (I have all states to feedback).
As the output of actuator is limited and the controller has an integral term, I should implement an Anti-windup scheme to avoid the windup of integral term. So, what type of anti-windup do you suggest?
Thanks in advance.
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For digital implementations, I just stop integrating the error signal if the controller command signal, i.e. the input to the combined plant/actuator, saturates (i.e. hits +/- max). I know there are more sophisticated approaches, but I have always wondered why anything more than this is needed (?). 
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see attachment please.
I have successfully come up with a new helicopter design that I call the NOTA MRH (NO TAil Mono Rotor Helicopter). The picture shows it's basic design. This helicopter does not need a tail rotor for torque reaction. The person flying this helicopter will only mind about the single main rotor cause that's the only rotor on the helicopter. It can work well for stealth helicopters. It is not a Mono copter or Coaxial helicopter nor Tandem helicopter and can easily be fitted in a space capsule if required for future landing.
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My suspicion is that 1) the small radius rotor would have to rotate at an unacceptably high rate to counter the torque by the main rotor, 2) the resulting turbulence would likely affect the performance of the main rotor, and 3) it would be a very wasteful design, as the small rotor would not contribute at all to lift, so all the energy spent on making it rotate is wasted.
The reason why the standard helicopter design works is because the small rotor is at the end of a large moment arm. The reason why the coaxial design works is because the two counterrotating rotors both contribute to lift.
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I am interested in using a small/miniature biofuels/diesel powered engine to both charge the batteries (while the solar cells are not producing enough power) and to directly power the 4 electric motors of a small drone (which is used as an aerial platform for cameras and remote sensing equipment, like LIDAR). Which would be the better engine to use, a conventional reciprocating-piston engine, or a turbine? Both have rather high "costs" in terms of start-up current draws from the batteries, but I am thinking this factor would about equal-out for each type, and thus could be disregarded. However, how should fuel-consumption compare for the same amount of power produced from each type? Any thoughts on which maker/model (combination with generator/starter ?) is the best?
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;O)
... I mean, concerning efficiency, there is nothing better than only to use your battery, without such an onboard charging system, but we also know that there are restrictions with payload, flight time and so on and it really could be useful to think about it. Maybee there is a possibility to slimm your plattform to extend flight time and range...
 If you did not find the following link bevore, have a look at it. Maybe, it could help:
Also in an rc-forum discussion in Australia they linked the side: But I am sure you already could find this. Nevertheless, the link:
 There is also a discussion about the topic in a german rc – forum. There are some interesting ideas, but all in all they are not convinced by the idea: There would be much professional development to do to get an effective system...
Jetcat has integrated a small generator to charge the systems batterie, but this will not help you if your copter would not be driven using a jet-engine. But maybee here you can find proposals/stimulations for own ideas:
In my group we also use rc helicopters, but we never did fly such a long range mission. Also in germany it would not be allowed to fly out of sight. But the mission you describe would be perfect for a petrol or jet driven Helicopter System. It should be possible to fly your mission with such a platform. But you would have to develop and configure such a system especially for such a mission, you also need an excellent pilot and as you mentioned, this also would be an other platform again, spend lots of money and so on…
Mybee you can find some better hints at the links and if you would find a solution, please keep me up-to-date.
With best regards and good luck for your realy interesting mission...
Patrick
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I am waiting for your responses.
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I am not a specialist of transonic aerodynamics and I try to understand the difference between buffet and buzz phenomenon.
1) I wonder if the buffet is the periodic variation of lift due to shock wave oscillation and buzz is the name of the aeroelastic answer of the buffet excitation. Is that right ?
2) What is the link beetween the shock wave oscillation and the boundary layer.
3 Is it possible to have buffet without boundaly layer ?
Thank you
Best regards
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If you considered a spring, it will be like considering the elasticity of the structure. In that case based on your BCs an ICs, you could observe damping or diverging or self-sustained response (flutter). But as @Fulvio_Sartor said buzz is related only to ailerons vibration. 
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Greetings.
I am working on a Systems Engineering project. As a team, we have to find the reliability, availability and maintainability figures or values for different components in an aircraft. For example: powerplant, avionics, airframe structure, fuel system, flight control and electrical systems. Since, the data on these systems are hard to find in a public domain; any amount of help on how or where to find these values would be greatly appreciated. Looking forward to some positive response.
Have a good day.
T Vijayan
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Hi
You can find these data in the links below:
Nonelectronic Parts Reliability Data
Electronic Parts Reliability Data
But you have to pay to access it.
 
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Hello,
My name is Mykolas. I live in Lithuania and currently I am studying for my pilots license and Aerospace engineering masters degree VGTU (Vilnius Gediminas Technical University).
My final paper is about an importance of English language in aviation. So I would like to ask for help:
1. Information about techniques of evaluating English knowledge (especially for evaluating professional requirements).
l
2. Any article about incidents because of miscommunication or recordings would help.
3. Expert opinion on the subject would really help.
4. Information on where I could find statistics about the traffic in airports would help.
5. Any ideas to make the subject more useful or interesting would also be very appreciated.
I will mention and give credit to anyone who will help me on my Master's dissertation.
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As an Air Traffic Controller, I like my instructions to be understood by the pilots. If both of us are going to follow different languages as a medium of radio telephony, then imagine the confusion! Already we are facing the problem of phonetics and different pronunciation among all the stake holders in aviation like pilots,ATCOs and ground crew.The use of non-standard procedures and phraseology can cause
misunderstanding. Incidents and accidents have occurred in which a contributing
factor has been the misunderstanding caused by the use of non-standard
phraseology.
The worst accident in aviation history i.e.,Tenerife collision between two B747s on 27/03/1977 was due to non standard R/T only. So standard and uniform R/T is a must for safe operations. Language was a part of important factor in many accidents like Milan Linate airport MD10 and a Cessna. etc
Follow the link to know about the english tests satisfying the ICAO SARPs for Language proficiency requirements.
Regarding the air traffic through out the world check ACI (www.aci.aero) or IATA (www.iata.org). They are publishing the air statistics regularly in their sites.
If you feel I may be of further helps,please inform me.
Regards and best wishes.
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Using stereovision camera in uav navigation.How can it can create a navigation waypoint
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number of articles on the sub. question are available. interested person may refer to it to understand the solution thoroughly.don't look for short cuts.
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Of the current systems that exist onboard an aircraft, which if any are able to transmit location data to a ground receiver station?
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ADS-B. But not all aircraft have it.
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I am in need to validate the codes for aeroacoutics computational simulation. What are the standard test cases in computational simulation of Aeroacoustics, whose experimental data will be available?
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Did you have a look to the benchmark problems used for the computational aeroacoustics workshops? They are available on the NASA Technical Reports server. There are different test cases of increasing complexity. Analytical solutions are usually provided as well.
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can autopilots controls the aircraft in rainy air and gusts?
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thanks a lot for your your guidances
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I am working on an Aeroacoustics Competency Development Program.
As I don't have much solid experience on Aeroacoustics and its allied processes, I would like to know which will be the best way to start with.
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Hello Green
This is my collection of aeronautical books:
I hope it will be helpful.
Pass : Lahidjan_Sadatmahalleh
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I need some inputs for optimizing W/S of an aircraft.
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HI,
Peter pointed us towards the answer to this problem. The W/S will depend on the main function and performance of the aircraft - speed (cruise, on function, take-off, etc). As an illustration, a steady flight with low gust sensitivity would requires high W/S. But this would mean high take-off and landing speeds.
Meaning, there is no short answer to this question. Torenbeek do give a method to arrive at compromise best.
Wan Zaidi
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I have simulated a system using pure simulink blocks. Later I substituted some of the subsystems by commands in a matlab embedded function. The results are completely different. What could cause such diverge results?
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I usually get good results using following simulation configuration in my experimental validations (where I use C language funtions): In your Simulink diagram, menu Simulation/Configuration parameters; Solver options, Type: Fixed-step, Solver: ode1 (Euler), Periodic sample.. : Unconstrained, Fixed-step (fund. sample time): 2e-6, Tasking mode for periodic sample times: Single Tasking. Then I use 2e-6 as a simulation sample time and about 1e-4 or greater for the controllers and estimators (previously dicretized).
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Hi, I'm Ramprasanth from Aeronautical Department. Can anyone explain this question clearly?
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Ramjet belongs to air breathing engine and inparticular, in the category of steady state combustion.In case of ramjet, air with supernsonic speeds gets compressed by supernsonc and subsnoic diffuser by means of shock waves,  mixed with fuel from injectors, ignited by means of ignitors so as to develop sufficient pressure and temperaure casuing combustion to take place and combustible products expanded through nozzle producing necesawry thrust requried to propel jet engine. Supernsonc combustion is not possible as air must have sufficient pressure and temperaure for combustion. KE of the air gets converted to pressure energy so as to cause necessary combusiton. Compressor and gas turbine are eliminated in this engine, and diffusers are provided.  .   
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it was long back in 2007-2008. Better is that you disclose some details or ask some specific queries otherwise beating around the bush will fetch nothing
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Warp field generation using metamaterials and sub-nanoscale casimir cavities architecture (e.g. optimising multiscallar geometry of warp propultion). 
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I can't believe NASA is funding this before having established human settlements on other solar-system bodies with a less ambitious but much better understood propulsion technology, namely nuclear power.  Warping space to any practical extent would probably require extreme energy densities that only nuclear processes - and lots of experience manipulating them - can provide.
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For Velocity, Acceleration, 'g' , Load etc.
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SHORT TERM MICROGRAVITY EFFECT ON ISOMETRIC HAND GRIP AND PRECISION PINCH FORCE WITH VISUAL AND PROPRIOCEPTIVE FEEDBACK
P. Pastacaldi, P. Orsini, F. Bracciaferri, G. Neri, M. Porciani, L. Liuni, V. Zolesi
Advances in Space research, JASR 6283. Vol. 33, Issue 8, 2004 , pp.1368-1374
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I am working on improving cockpit automation interfaces and will be using a PC based simulation as part of that effort. I am considering using Microsoft’s FSX, Flight Gear, X-Plane or Prepar3D. I’m leaning toward Flight Gear as it is open source and may be easier to develop interfaces with it using custom software. I wanted to ask other researchers what opinion they have regarding the suitability of these platforms for academic research especially when failure simulations will be created?
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I don't know much about the other sims, but X-Plane lets you access simulation data via UDP. Two of my students wrote an interface which we could use to get sim outputs and write sim inputs. The number of accessible states / parameters is fairly comprehensive.
You'll find information about the protocol at http://www.nuclearprojects.com/xplane/xplaneref.html
Cheers,
Marc
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From the plots.
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You can divide the pressure distribution around a body such as an airfoil into two region beginning from the leading edge.
In the first region near the leading edge the pressure begin with a maximum value at the stagnation point then decrease up to a minimum value, while the airflow velocity increase along the surface. This is the favorable pressure gradient region (dp/dx<0). There is no risk of separation in this region
After a minimum point the pressure begin to increase along the surface, while the velocity decrease. This is the pressure recovery region, or  unfavorable adverse-pressure gradient region (dp/dx>0). In this region there is a risk of separation if the pressure gradient is high enough. After a certain point on the cp(x) graph in this adverse pressure gradient region if there is a constant pressure region, this region may be an indication of separation. However this is not so clear. Therefore it is better to calculate the boundary layer on the surface, then evaluate if there is a point where Cf is near zero.
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I would hence, like  to know the formula used to calculate the descent velocity of the object to which it(propeller) is attached.
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While very early aircraft were fitted with constant pitch propellers, modern propeller aircraft are fitted with variable pitch propellers which accomplish the following:
Adaptation to aircraft speed
Reverse used at landing
In case of engine failure propeller is feathered that is, oriented along the velocity so that it does not rotate. For that reason when one of the engines of a propelled aircraft fails one of the first procedures to apply is to feather the pitch. Failing to do so keeps the propeller rotating and when piston engines are concerned the compression of the cylinders represents a considerable resistance to its rotation and this adds additional drag. This is not the case with turbine driven aircraft in particular when the propeller is driven by an independent turbine stage(s) called free turbine in which case there is much less torque resistance.
When the crew attempts to re-start a piston engine they just un-feather the propeller which causes the engine to rotate again and thereby eventually re-start,
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Is the derivative of the error the rotation between the derivative of the desired and the derivative of the actual angle or simply the derivative of the error equation?
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The following thesis may prove helpful to you:
T.V. Marcard, Design and implementation of an attitude estimation
system to control orthopedic components, M.Sc. thesis, 2010:
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I need a transient aero-thermal test case for the validation of numerous procedures. I have one very good test case of x-15 but I need one or two more test cases.
X-15 transient aero-thermal test case contains complete detail of free-stream conditions, material thickness, temperature measurement instruments locations, and skin temperatures.
If anyone knows some other test cases which have these all data available for study please inform me.
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I have seen few solutions solved by NASTRAN CFD package. It may be useful for you.
Dr.S.Ravindran
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I am seeking help in solving the problem which is attached here. Which software is most suitable to solve this problem?
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Try this one:
Comsol - Heat Transfer Module
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I want to develop a new test standard for oxygen masks used by flight crew members.
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Which kind of oxygen mask do you develop : for fighter aircrafts ? safety oxygen mask in commercial flights ?
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I have a control volume as attached. Left is inlet, right is outlet, top is symmetry and bottom is axis (it is a 2d axisymmetric analysis). What you see is a vehicle and there is a piston-cylinder mechanism inside it. The piston moves and creates pulses. There is no flow from the inlet, so the velocity of the inlet set to "0". When I initialize the case, it gives a warning as "turbulent viscosity ratio is limited to 1e+5 in xxx cells". When I plot turbulent k contours, I see that every turbulent k is over the limited value. What might be the problem?
I set inlet and outlet turbulent parameters to 0. The warning disappeared, but then it did not solve the case. I changed the boundary inlet to wall and the turbulent viscosity ratio warning still appears. I am really confused. Do you have any ideas?
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Mr. Kumar, I think I have found an answer to my problem.
When I define zero velocity, there will be no turbulent viscosity. Because turbulent viscosity is a result of velocity. So no velocity means no turbulent viscosity.
Since turbulent viscosity ratio is the ratio of dynamic viscosity and turbulent viscosity, they both must have values other than zero. I don't exactly know which parameter is in nominator or denominator, but if one is zero and is in nominator, then the ratio will be zero. Otherwise, it is infinity.
In my case, I think, denominator becomes zero and the ratio goes is infinity.
I must say that I am not an neither expert in the subject of turbulence nor in fluid mechanics. So, my answer is not more than an idea.
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Temperature reduction factor for various material
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Dear Sir, r u having any Docs For finding temp red factor?
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We know that the path of a point on a Bezier curve can be controlled through the control points of the curve. This parametric curve ranges from t=0 to t=1. This means the velocity is uniform for fixed control points. Is there any research where the possibilities of a non uniform (assigned) velocity for a point on a Bezier curve has been discussed?
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Good points above. In practice what you need is to reparametrize by arc length. Rick Parent's animation book covers this nicely. A numerical approach is to build a table of arc lengths using a linear approximation. Small steps in the parameter 't' give points on the curve. Calculate the linear distance between each pair and enter the total distance travelled in the table as (Euclidean) distance against parametric distance. This can be normalized by dividing by the total distance to give a 0<=d<=1. Given t the distance can be found - use linear interpolation to find a distance between table parameter values and vice versa. This is an approximation whose accuracy depends on the step size. In Rick Parent's book there are various ways of controlling velocity and acceleration along the curve once arc length is known, but sow-in slow-out is most common in animation, often done with a cubic.
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Can anybody guide me on how to analyse the Impeller of the Centrifugal pump in Ansys-CFX/Fluent/Solid Works, or provide a related tutorial?
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The below 2 tutorials may not be exactly matching your requirements - Still both will be useful to you I guess
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I am trying to write a project proposal and I am having a problem referencing my proposal. Thing is I know things like dust etc can cause some damage to propellers which might lead to dents and cracks and etc, but what I need is research papers that prove this Where can I find them?
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Unless there is specific research looking at the effects of debris/precipitation damage, you're more likely to find relevant resources within maintenance documents or accident reports where such events have been reported. For example, search "CASA propeller stone damage" for relevant information in the first listed article from the Flight Safety magazine. At the more severe end of the spectrum, an academic at Loughborough University has researched the aerodynamics of battle damaged wings, which may have some relevance to your proposal - search the AIAA database for related papers.
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I just read a paper from Antony Jameson published in Progress in Aerospace Sciences 47 (2011) 308–318, http://www.sciencedirect.com/science/article/pii/S0376042111000029
He discussed CFD simulations of the Korn airfoil, and stated that some numerical methods failed to give a shock free solution. I am really impressed by Jameson's work, he did a mesh convergence study of this problem (Mach=0.75, CL=0.629) and give a new shock-free cruising condition (Mach=0.751, CL=0.625).
I tested this case with my own codes and failed. I would like to know from other CFDers, whether your code can produce the shock-free solution. Is there some important factors I need to pay attention? e.g. accurate treatment of the solid boundary condition? point-vortex at the far field? etc.
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Hello,
Jameson did a numerical optimization using adjoint method. So this means he modified the original airfoil which is not shock-free at these conditions, so the results you obtain may be fine. See Harbeck, Michael, and Antony Jameson. "Exploring the limits of shock-free transonic airfoil design." AIAA 43rd aerospace sciences meeting and exhibition. 2005.
Regards
François
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What are the anti-icing system techniques used in aircraft particularly in piston engine aircraft like Cessna 172?
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A Cessna 172 has no anti icing system, as long as i remember a electrical pitot heater for preventing freezing over the pitot tube and a carb heater for preventing formation of ice in carburetor are the only two ways to prevent ice from forming; for that the C172 cannot flight in cold weather conditions.
There are two common types of anti ice systems: the electric thermal heating system and the bleed air (pneumatic) system.
The electric thermal heating system are most commonly used on windshields and propellers. The bleed air anti ice systems is used by most jet aircraft to prevent ice from accumulating in leading edges and flight surfaces (this air is taken from the engines or an independent compressor unit).