Questions related to Flow
Reactor working schematic shown in the annex, driven by the stirring rod fan blade rotation of the metal hanging piece of the rotating flow impact, and the external conditions are satisfied with the Taylor number (Ta) to reach the critical value of the Taylor vortex. Then. Can flow in a high-temperature, high-pressure rotary reactor be analyzed using Taylor vortex theory?
[[ lfh note: This question has been hijacked by mistakenly celebrating a very non-responsive lecture on turbulence with Popular Answers. The lecture is even placed before discussion of the question. In my opinion it was without malice by RG or the person who posted it. Please read that "answer" on Page 4 below after reading actual discussion and clarification of the question, because the lecture is good history. ]]
[Original question comment] I think that the process of flow curvature formation at any scale in a fluid requires a pressure gradient across the curvature. The result outside the curve is increased internal thermal energy there. During subsequent decay of the curved flow, the curving kinetic energy fills the low pressure inside the curvature.
Why do all producers of ideas (fiction writers, doctoral students, journalists...) feel that it becomes easier to generate more ideas shortly after they submit their writing tasks? Is it psychological in the sense that their worry about meeting the deadline is responsible for inhibiting their inspiration? This remark comes from my personal experience as a doctoral candidate who feels that the burden gets lighter after submitting my work.
Share your thoughts!
I am interested in purchasing a non-intrusive flow meter for measuring the flow rates for different fluids circling inside enclosed pipes. I've seen the ultrasonic flow meters as a possible solution.
Can anyone recomend me some manufacturers and/or links ?
I have noticed that there are single microscopic slide/slip chambers (Cytodyne, Flexflow, IBIDI) and many studies have used these chambers. I wondered how it is possible to have more robust data by using a single fluid flow chamber (1 replicate) and a control?
I am confused between bright color or other
can I try
lymphocyte (PE) and the other activation marker which will seen on it will (V450 and percp.cy5)
note that : i have already one marker from the rare antibodies with APC color which will use definitely at the panel
I have been doing research on the leak detection of pipelines for some time. I did the simulations with simcenter software. But unfortunately, I tried to detect the location of the leak using Kalman filter in different ways, but it is not possible. Is it possible to guide me? Is it possible to send me the MATLAB code so that I can try on my own water pipelines and simulations?
I have a situation in a T-Junction Microfluidic device. I am generating water droplets in oil medium using 2D simulation. I have fixed the velocity parameter of both liquids and increase the width of the main channel (Horizontal long channel where oil is passed) ONLY. I see a decrease in average flow pressure in the device with increasing width of the main channel. How do you justify?
Hello! I am running flow cytometry on PBMCs and trying to optimize my voltages for FSC and SSC. The voltages I used were: FSC: 170 and SSC: 273.
However, what was strange is that on FlowJo, the units for FSC-A and SSC-A were from 0-1000, and 97% of my cells lie within that axis. I am perplexed, as most of the FSC and SSC units I find online are from 0-250k.
I will really appreciate if someone could explain to me why there is such a great disparity, thank you!
I'm modelling heat transfer in thermoacoustic device using Ansys fluent - the problem is 3D. Please what is the best way to specify the mean pressure of 5bar in the domain. The flow is driven by oscillating pressure at the inlet and outlet (that's there is reversed flow).
I'm getting divergence in solution after the solution is first converged at about just 5 time step. I specified the mean pressure to be the operating pressure, while I used udf to specify the inlet and outlet oscillating pressure that is driven the flow. I enabled gravity.
Suggestion will be appreciated.
While estimating the contraction and local scour, there are many equations in the literature mostly produced by using prismatic channels (e.g. rectangular). However, in real case studies, we are modelling the rivers with their irregular cross-sections and for scour analysis, the approach channel depth or flow depth at just upstream of the bridge could be "Maximum flow depth", "Local flow depth" at the upstream face of pier, and "Average flow depth".
The question is which approach should be used for contraction and local scour?
For contraction scour the answer is most probably the "Average flow depth".
What about the scour around piers?
Does anybody know of a self-report measure indexing the "runner's high" phenomenon (outside of flow scales)?
The term “runner’s high” (RH) is commonly used to describe the feeling of euphoria experienced by athletes engaged in endurance running. This state is usually characterized by (decreased) anxiety, relaxation, analgesia, euphoria, effortless running experience, and a “lost sense of time”.
I am wet spinning and have two syringe pumps. I want to run one pump at a time but as the syringe gets low on material start the second pump and turn the first pump off without interrupting the flow rate of the outlet. While the 2nd pump is running, I can fill up the first syringe and start that pump when the 2nd pump syringe gets low. So on and so forth. I would like to know if there is a directional valve that can help me achieve this. I was thinking a shuttle valve may work but I do not know if it will affect the outlet flow rate when I turn one pump off and another on
I am trying to measure the pressure values of a venturi at the inlet and throat sections. The fluid is air at room temperature.
1. The main pipe diameter (D) is 6 mm and the throat diameter (d) is 3 mm. Measurements below 10 l/min do not satisfy Bernoulli's equation.
2. The main pipe diameter (D) is 7.5 mm and the throat diameter (d) is 4 mm. Measurements below 20 l/min do not satisfy Bernoulli's equation.
Is there any lower measurement limit for venturi flowmeters? If so, what is the underlying physical mechanism of this behavior?
Thank you in advance
I'm trying to design an irrigation system in which I'm able to get slow liquid flow (dripping) out of multiple holes (exit points) that is uniform across all of the holes. The issue I keep running into is that any discrepancies in the holes - be it slight differences in size, orientation, etc.- results in a preferential path for the liquid and the flow becomes nonuniform; it flows fast out of some holes and slow (or not at all ) out of others.
Any thoughts on an approach would be greatly appreciated.
I am reviewing some mobility flow data of the United States. Does anyone have recommendations regarding public access to big datasets such as mobile phone data, smart card data, or daily activities with the explicit origin and destination locations within the US (preferably, the individual-level data and not city or county level)?
I have an O shaped water bath with a square cross section that I am circulating with an immersion circulator. How do I measure the flow rate at a given point in the bath? Can I use an anemometer even though that’s used for air?
I am doing a cell culturing experiment in a fluid flow chamber made of PDMS material. I was wondering how to sterilize the pipes and the flow chamber before/after the experiment, in case I want to use the same chamber for the second and third biological repeats?
My question is regarding how to make a custom-made culturing flasks (micro-fluidics) using a mold and flowable material that is similar to resin? what material is the most suitable in terms of cytotoxicit/biocompatiblity?
I work in the northeastern USA and I am trying to find options for temperature/level loggers with automated real-time data collection and cloud-based data storage for easy data access. We have a network of sensors in our study watersheds, and data download takes up a lot of time and resources. Anyone have good luck with any sensors and/or data plans that offer cloud-based data access?
I'm performing a cryogenic turning process.
The temperature are recorded from the thermal imaging camera.
Can I use these temperature values to simulate the flow characteristics and behaviour of the cryogenic coolant?
Is this an acceptable thesis?
Thank you in advance.
We have online GC-FID and GC-TCD (Mod: 2014) connected with flow reactor system.
This GC-FID/TCD is connected to a gas line coming from flow reactor system which I used for cascade reaction. In this flow reactor system ethanol is pumped with constant rate & heated at 160 oC and an inert gas (flow controlled by MFC) is using as carrier gas for ethanol. To prevent from condensation of ethanol, the line is wrapped with heating tapes. Further, the gas/ethanol flow through a loop in the GC-FID and GC-TCD, and when the sampling process starts, the GC takes the gas in the loop to column by pressing the switch (activate sampling at same time).
In this system, I flow the gas/ethanol at constant conditions in flow reactor for the long time as well, but I get instable peak area of ethanol in GC-FID as depicted in attached figure.
I tried a lot by changing the flow reactor parameters, checked gas leak, pressure regulators, sampling time. but facing the same problems.
Could anyone suggest me, where is the problem or anyone facing such type of issues?
Thanks in advance
We're having a bit of a problem while trying to find progenitor populations in bone marrow.
The protocol for CyTOF includes staining the cells, fixation, methanol perm for 15min, intracellular staining, fix and washes in 800g and Ir staining.
After washing the methanol, we had 5 million cells. However after Ir staining we were left with 3 million. Meaning we lost 2 million cells in the process. In addition, our CyTOF keeps clogging because of strange aggregates.
This feels a bit excessive and I was wondering where in the process we had it wrong.
Methanol is ice cold (-20C), added drop-wise, centrifuges were done in 800g.
Is it possible the cells were more vulnerable after the methanol and exploded in such speed?
I'm currently developing my first lateral flow immunoassay and I have come accross some publications like
I know that ANSYS uses J2 flow theory (incremental plasticity approach) to solve the elasto-plastic problem. But I want to compare the results of flow theory of plasticity and deformation plasticity theory. Can I do it using ANSYS or any other commercial software
I am familiar with Microsoft Office Suite but didn't have a Microsoft Visio license. Is there any free alternative that can be used to draw flows and diagrams for research papers/articles?
I searched online for Visio alternatives, there are many online services, but they are not user friendly and flexible.
Note: I am using Microsoft Word to write my articles.
I am looking for some references to understand the flow patterns when high-velocity gas is injected into a liquid tank. I want to see how the flow patterns are changing from low-velocity gas injection (bubbly flow) to high-velocity gas injection (droplet flow?). Can large pipes somehow be analogous to the flow patterns in liquid tanks when gas is injected?
Does anyone know the techniques to measure pressure change of less than 500Pa with at 100-150 oC? We would like to measure the air flow pressure change of less than 500Pa within a static pressure of 100KPa to 1.6MPa environment.
I need to simulate the transition of Flow through Coarse Porous Media such as Rock-fill dams, to investigation of Water level profile in each distance from up-stream and determination of discharge of fluid seepage from the body of these media. Notice, I want to simulate a Single-Phase Flow.
How can I simulate this project? Please suggest and introduce a useful software for this issue to me...
What is your idea about Flow 3D, Fluent, ABAQUS,...
Conference Paper A numerical study of the flow through coarse and homogeneous...
Conference Paper Transition of Flow through Coarse Porous Media with Network ...
I'm trying to find an empirical correlation for obtaining the critical Reynolds number in a 180-degree bend/curve/elbow with a circular cross-section (See the figure). I've searched for a lot of papers with no luck, but I know I’ve seen it somewhere before.
Can you recommend an article or book with a correlation for the critical Reynolds number as a function of tube diameter and curve radius?
Thank you in advance.
They have been proposed as the cause of the abnormal movement of the most distant galaxies in the observable Universe.
To find the developed area of flow inside the tube we use the empirical relation (X = 0.05 ×D ×Re ). Can we use this relation to find the position of the developed flow inside the spiral tube?
How to measure discharge of a canal by surface float method?
If we know flow depth, top and bottom width of canal. And canal is lined with cement concrete. What should be size, weight and material of float? What is relation (Multiplying coefficient)between surface velocity and mean velocity?
I'm working on an overland flow model (MIKE 21 Flexible Mesh) where I have to set some open boundaries with a specified water level. After simulating a rain event, the triangulation mesh elements near the boundaries have water depths which are extremely high (hundreds of meters) and flow speeds of several hundreds of meters occur. What may cause this?
Hello , for which percent we can trust in numerical solution results for energy and fluid flow problems in Fluent , Comsol , ... etc ?
Please verify the percentage for which software.
I am trying to determine whether tree cover (in proportions) at one site is affected by stream flow (and thus flooding, periods of drought etc.) recorded at the same site. The tree cover data is limited to a <20 records over the last 50 years while the flow data has a value for every month (average deseasonlised) for the last 30-50 years. What meaningful statistics would be valuable to assess the effects of flow on vegetation cover? I will repeat the process for each site to assess spatial variation.
I would like to find a way to build a model of the system I'm starting to research. Or really find any small amount of progress. Here's a snapshot of what's happening: Air is flowing (from atm.) through a porous media in what should be a vacuum chamber. I'm not concerned right now with why or eliminating the flow. I just started this in the last 2 days so I know very little and I'm still waiting to get some info from my peers. Rather sit and wait I want to try and see if I can get a leg up on some basic theory and possibly explore any similar mathematical models. I believe my peers want to characterize the flow so they are able to predict the behavior.
I am an undergraduate student and have taken an intro fluid mechanics class so my background is not in depth. I've been looking at some books and journal articles. They are okay but I'm just kind of aimlessly picking them.
A converging nozzle increases the flow velocity and decreases the static pressure as per Bernoulli equation. Can a liquid flow through a converging nozzle result in static pressure below the vapour pressure of liquid and evaporation of liquid?
I need the GAMS code for distribution load flow. In this regard, I have found the (improved) backward-forward sweep suitable to my work. So I need the GAMS code for this method.
I would appreciate if anyone can share this code with me.
Why does the imbibition process need a much higher pressure than the drainage process in the two-phase fluid flow in porous media?
Principally, because capillary pressure plays a positive role to drive the flow of wetting phase (e.g., water), the flow in an imbibition process (e.g., water displacing oil) should be easier (less pressure cost) than in a drainage (e.g., oil displacing water) process.
However, as shown by many laboratory core-scale test results, an imbibition usually needs a much higher pressure (e.g., 100 kPa) to drive the flow than a drainage (e.g., 20 kPa) under the same injection rate (e.g., 0.5 mL/min).
The high pressure during imbibition should be not due to the viscosity difference between fluids. When injecting either one of the phases alone in the media, the pressure drop is quite low.
I was trying to push water through a piece of porous media. I was measuring the pressure drop of it under a constant flow rate, and saw that the pressure drop kept increasing over time.
It starts as ~1 psi, and increases to like 10 psi after 7 minutes
Does anyone know why? This only happens to one type of my samples.
Edit: this is an experiment. It keeps increasing, but I can’t measure accurately because my tunings start to leak after 12 psi
Two nozzles of different output diameters (0.20 mm and 0.25 mm) are being used to take mass measurements for an analysis over a time period for the same input pressure.
It has been observed that the standard deviation in the measurements increases in with an increase in diameter of the nozzle.
Is this true? Does an increase in diameter causes greater fluctuations in the flow for the same input pressure?
I want to be able to model some slug flow data using the unified model for gas-liquid pipe flow via slug dynamics by Zhang et al., 2003. Following the flow chart for slug flow calculation is challenging. Any help?
Hello all, currently I am doing experiments, in these experiments I am using a nozzle in order to cool a hot surface, meanwhile I am changing the water flow rate, and what I noticed is, when I change the water flow rate, the cone angle changes, and I am wondering whether the quality of the nozzle is low, or the water flow rate may affect the cone angle of the nozzle! Any answer will be very appreciated. thanks in advance for you all... :)
I can't run MODFLOW Model using PEST in Visual MODFLOW Flex 4.1, and i can't find the tools PESTCHEK.EXE and INSCHEK.EXE in the PEST distribution files to run the model , Is there any help, please ?
I have read a book about turbulent plumes flow by rodi, there are 2 formulas about momentum flux and volume flux. In both formulas there is a constant K, but rodi didn't tells about the number. the formulas will develop into two parameters, plume invariant and richardson number. I need both of the values for my undergraduate thesis. So if you could tell me, i would be so grateful.
In a student group work we are making experiment on participants playing video games using DFS-2 flow evaluation questionnaire. We are looking for experimentation using this same questionnaire for other kind of activities, not related to game. the goal is to compare results.
State of forces acting on the typical sand particle due to water erosion is represented in the figure. Where of particle W, cohesive force FC, the angle of internal friction and resistance force FR . comment on them. If you find any fault kindly give your comments.
check if the cohesive force that acts between the particles representation is correct/wrong?
Resistance force, FR= given in the linked file,
Figure is given in word file attached
I'm doing a differentiation experiment with flow analysis, comparing two cell lines: one is the wt cell line, and the other is a stable line transduced with our GOI + GFP marker.
The GFP is just a marker and is not important for my experiment. Can I leave the GFP uncompensated? The panels I'm using are:
(1st panel) PerCP-Cy5.5(Blue A), PE-Cy5(Y/G C), Alexa700(Red B), and sytox orange(Y/G E).
(2nd panel) APC(Red C), APC-Cy7(Red A), and sytox orange(Y/G E).
I checked the spectra and it doesn't look like GFP will overlap with the other fluors? Also, I'm worried that I can't really compare the GFP- cell line with the GFP+ cell line if I compensate for GFP; it might overcompensate the GFP- cells.
I am trying to find an empirical formula/graph/simple calculation that I can use to predict the flow pattern inside a horizontal rotating hollow cylinder. I intend to find a method by which I can understand the onset of different flow patters (i.e. annular, rimming, pool .etc) by varying the liquid fill percentage and/or the rotational velocity of the cylinder. I want to find out such data for a variety of setups and hence am not using CFD or experimentation.
It would be of great help if anyone could suggest a source to find the same.
MSc. Mech. TU Delft
I'm studying the flow behind a bluff body and I have done a large eddy simulation in ANSYS-FLUENT 17.0. Now I would like to show the shedding vortices behind the bluff body in CFD-post; but I can't find vorticity in the list of parameters to plot the vorticity contour. Does anyone have idea?
I’m having some trouble simulating laminar steady-state flow over a sphere (OpenFOAM). The solution is converged but I’m having about 15% error on the drag coefficient (CD) for 10 < Re < 100, and about 20% for Re <= 1. Please, see some pictures of my simulation in this website http://imgur.com/a/AxIWE for more details.
I’ve tested finer meshes to ensure the mesh independence. (The CD of the mesh from the pictures differs only 1.5% from a 15.4% more refined mesh)
From the picture "Pressure over the sphere and U streamlines for Re = 80", it seems like the flow isn’t steady (because of the different size of the recirculation zone), but shouldn’t it be for Re = 80? The separation zone is increasing the pressure in the back of the sphere, is that right?
I think that there’s something strange with the pressure field, because for very low Reynolds numbers (<= 1) the drag should be predominantly viscous (the pressure CD represents 33.6% of the total CD).
I’m using simpleFoam solver (SIMPLE algorithm), GAMG for pressure (p) field and smoothSolver for velocity field (U) (see pictures for fvSoultion and fvSchemes). I’ve already changed those field solvers (PGC, GAMG, …), refined the mesh, reduced the tolerance of p, checked the boundary conditions and checked the size of the fluid domain, but the results barely change.
Does anyone have any clue what’s wrong, please?
Thanks in advance.
I am trying to test for Jurkat activation following stimulation with peptide-pulsed APCs. I am looking for a flow-based assay. Are there jurkat markers other than CD69 that are up/downregulated upon TCR activation?
I am trying to design a counter rotating wind turbine system and looking for an alternative method to find blade properties for the second rotor(downstream of flow of first turbine). For a single rotor wind turbine, Betz and Schmitz methods help out, but I can't find a similar approach for counter rotating wind turbines.
Streams are freshwater with fast flowing current (velocity 0.4 to up to 1 m/s), from main channels (C.20 metres wide, depth c. up to 5 metres in pools) to tributary streams (5-10m wide, mostly wadeable). River has rocky bed. Mini rapids (main rivers) waterfalls and cascades are common features.
Stream water is clear at baseflow with low conductivity (24.7 +/- 5.7 microS/cm) but gets turbid after rainfall.
Watershed is forested - gets pitch dark at night
I am trying to calculate the convection coefficients of the different faces of a building. Thus, I am wondering how to deal with external convection with a wind of a different direction from completely parallel or completely normal to the surface subject to the convection (see the attached picture).
For instance, under EES, for a vertical plate, there is a correlation dedicated to parallel flow, another one to normal flow and another one for a flow directing to the edge of a diamond shape. But no correlation is proposed for an any wind direction for a vertical shape.
By advance, thank you
I am doing master thesis in which I have to optimise active power flowing through HVDC link and it is installed in parallel to AC line. I need to know how can I make obective function and what would be my constraints for this function?
According to my study, single phase model works better under Developing flow condition while for Fully developed flow its not work better. Because once the flow is developed the velocity profile for fluid with particles and without particle is almost same because single phase can not compute slip velocity. I used Mixture model for fully developed flow and get better results.
So, according to me for fully developed flow (hydraudynamically and thermally) two phase model predicts better compared to single phase.
What are your thoughts on this?