Geometry - Science topic

Eric Baird,

The third postulate,which is not a main or fundamental postulate or assumption,is the conservation of momentum,where the momentum is defined as the product of the relativistic mass and velocity.The clock postulate and the reciprocity postulate, each can also be called a third postulate.What the clock postulate and the reciprocity postulate are is kept to you as homework.According to Einstein et al.,special relativity has only two main or fundamental postulates or assumptions.

Di Wu, I would suggest trying other file formats or other importing settings.. But I always prefer to create my parts using Abaqus.

The Manning's n approach has been around for quite a while and may suit your needs quite well. Having said that, simply bear in mind that the approach assumes that all flow is 1-dimensional. In other words, this numeric model assumes that the water in the channel essentially flows in a straight line. Perhaps you are familiar with the old phase 'all models are wrong, some are useful'. Point being, just remember that the output you get is an approximation. In the off chance you have some measured discharge values in your study area, this can help quite a bit to calibrate the roughness values you end up using.

The HEC-RAS 1-D model relies on the Manning's equation for its calculations. If you crank up the roughness values, this will result in slower velocities and higher water surface elevations. Conversely, if you lower the roughness values, this results in higher velocities and lower depths.

As for the value of Manning's n that you use, I'll admit that these references might not be the most appropriate or useful for you particular application. Having said that, it doesn't mean that you can't learn something from these references either. So yes, they are 'oldies' but they are also 'goodies' and they can help to you start to better understand some appropriate Manning's n values.

Limerinos, 1970. Determinination of the Manning Coefficient From Measured Bed Roughness in Natural Channels

Arcement & Schnieder, 1989. Guide for Selecting Manning's Roughness Coefficients for Natural Channels and Flood Plains

Verified Roughness Characteristics of Natural Channels

Hopefully these references prove helpful. Best of luck with your project.

Just don’t do a full cell optimization again, do a fixed cell geometry optimization with your desired strain.

Hello. I'm trying to get it working with this simple model. If it works here, then I can transfer it to my project.

I don't have much experience with Intel's MPI, unfortunately. It's probably best to contact BIOVIA Support, I'm sure they'll have seen this before. Alternatively, you could ask Intel directly, but they aren't always very good at responding.

In the mean time, you could check the hydra service is actually running, by using:

hydra_service.exe -status

And you can test the Gateway etc using the Licence Administrator tools.

If all else fails, you can get the free academic CASTEP licence and just compile and run CASTEP yourself, with the input files generated by Materials Studio.

Just go through the given link below and I hope you will get the solution.

Philip James Hasnip Thank you

Thanks for the information. My question was a technical one.

I understand the importance of empirical data and this is part of the validation plan in my protocol. But training a forcefield usually requires high-level ab initio data, to begin with. Not to mention that it was shown that forcefields trained on ab initio data still reproduce experimental properties very well.

Dear Pran JYOTI Saikia,

Please recheck your model; you might have done something wrong in modeling. Moreover, you can convert plane strain analysis from 3D to 2D when the third dimension is way greater than the other two dimensions.

Also, you can learn how to do a proper cohesive simulation with this tutorial package: https://caeassistant.com/product/implementation-of-cohesive-by-interaction-element-base-methods-in-abaqus/

You can find some examples at this link. Just use the “cohesive” keyword and search:

Best regards.

Thanks for your answer.

Actually, I was looking for state-specific geometries from SA-CASSCF...

Thank you Mr. Daniel Galeazzi for your answer. I will try this out.

Hello, Debopam Ghosh. Alright?

I did the optimization and electronic transition calculations under both vacuum and solvent media conditions using PCM.

The difference is a red-shift and a higher molar absorptivity in a solvent medium. The spectral region of the electronic transitions in the solvent medium coincides with the experimental ones. However, it has a greater magnitude.

While it is not confirmed by Gaussian, and is not in their internal manual either: I have confirmed via test structures and cross checking of different values that this set of integers is indeed a matrix of atom indices in sets of 4, indicating the atoms involved with the degree of freedom, so the example I showed earlier becomes:

(1 2 0 0) bond length between atoms 1 and 2

(1 3 0 0) bond length between atoms 1 and 3

...

(2 1 3 0) bond angle between atoms 2, 1, and 3

(2 1 4 0) bond angle between atoms 2, 1, and 4

...

(4 1 5 6) dihedral angle between atoms 4, 1, 5, and 6

with 0 as null values indicating no atom there.

Hope this helps someone in the future!

Hi,

Just go through this video.

You will get the answer...

Hi Muhammad,

The equation mentioned above is nothing but the energy balance (conduction=convection at that surface), you still need to have the heat transfer coefficient (h) except which all other parameters could be iteratively solved. 'h' need to be an input to the numerical study.

Considering its natural convection, i would expect h to be somewhere between 0-10 W/m2 K. What i would suggest is to use a value of 5 ( convective heat transfer boundary condition at that wall) and compare the results. Trail and error could help you find that h value.

Hope it helps.

Thanks & Regards,

Rajesh.

Hi Faisal Qayyum,

Possible approach is to use Part>Create:3D-Shell-Sweep to draw longitudinal section of the tube (particularly, two paths for lofting), Shape>Wire>Sketch to draw circular edges, Shape>Solid>Loft to build the solid body without hole, Shape>Cut>Loft to make the hole, Tools>Geometry Edit…:Edge-Remove to remove unused part of longitudinal section.

using rotate option we can do it. However one has to take care of axis of rotation.

Select the object and click on rotate present in tool bar, it will prompt for axis selection, X-Y-Z, then enter the angle in number (45 in your case) and see the result after clicking on OK. you can see the figure rotation by changing the axis check box in the 3d object window it self.

CFD has been successfully used to design and refine small portions (leading or trailing edges, pitch, length, inlets and exits, guide vanes, etc.) of entire devices of this type (turbines, turbo chargers, compressor sections, expander sections, etc.) but not the entire device, as there are simply too many parts comprising the whole. If you are considering the whole device and how this might perform in a particular application, detailed CFD modeling will not yield all the information that you need. You will also need bench test data. Successful applications have followed this approach: 1) select the best available device for this particular application; 2) perform lots of tests; 3) improve individual aspects of the design to best work within the context of your application; 4) continue to test and refine. I seriously doubt that you can build a detailed numerical model of such a device, place the numerical model inside a commercial package like MatLab, find the optimum design parameters by considering many possible designs, spit out the design to a 3D printer, rip the turbocharger off a Porsche, bolt your device in its place, and expect a 25% increase in power output and corresponding decrease in fuel consumption. It's a nice idea but would only work in the movies. Advancements like this take years of effort and teams to accomplish with lots of failures along the way. Some very smart people have already been working very hard at Porsche to design their turbochargers. These can be improved and we hope to see that happen, but it will not be an easy task and it won't be entirely automated. Don't let this discourage you; rather, persist until success is achieved.

Dear Gerhard Martens and Spiros Konstantogiannis

Thank you very much for your comments, solution, and recommendations. I added one more loop into my code that includes the ratio of L1/L2 to check the approximate solution.

Hello Luis

Please use the structured mesh for the quality mesh and keep the skewness factor at least 0.5. You can use the face meshing tool for structured mesh.

Thanks. It seems to be multiple topics journal. This is nice, but the indexing journal does not appear in the website.

Hi dear Kourosh Vaferi,

You can import your 2D model from CATIA software into AutoCAD software and write output DXF.

Good luck!

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Dear Ketaki,

OpenFOAM I believe, is useful for creating porous media.

Check this out: https://www.openfoam.com/

Victor Milman Thank you for your response i will do it

Dear Daniel Paul ,

you can check *IMPORT keyword of Abaqus. This keyword can import an already solved part (with stress fields and deformations) to a new analysis. You can see the manual for more information of how to set up your model.

Hello Samir

Various formulas have been derived from experiments to calculate the reinforcement factor. see DOI: 10.1177/002199836700100205.

They are all approximate solutions and may require validation of results

"LIGO and cooperating institutions obviously determine distance r of their hypothetical gravitational wave sources on the basis of a 1/r dependence of related spatial strain, see on page 9 of reference below. Fall-off by 1/r in fact applies in case of gravitational potential Vg = - GM/r of a single source."

No. Fall-off for a single point source goes as 1/r² for the field strength in the static case. The potential goes as 1/r, but it is the field strength that is measured (and gives the strain).

However, for any time-dependent radiation, the leading-order term of the field strength falls off as 1/r. This is true for dipole as well as for quadrupole radiation. Because of the appearance of time-dependent terms, the derivatives in the field equations produce all terms from 1/r, 1/r²,... to 1/r^s, where s would be 2 for (non-existent) monopole radiation, 3 for dipole radiation (electromagnetic, e.g.), 4 for quadrupole radiation (gravitation), and so on.

A consequence of the leading order term being 1/r is that the energy current goes as 1/r² in leading order and that means that energy can be radiated away. Which would not be the case, if the leading-order term fell off faster than 1/r.

You cannot directly import a CAD file into Openfoam. You need to convert it into a good surface mesh (STL) and then use snappyHexMesh or cfMesh to create a hex-dominant mesh. Then, use checkMesh utility to verify the mesh quality. Also, you can visualize the mesh in Paraview.

Reference images

I am interested in the applications of Fixed Point Theory to differential and integrodifferential equations (fractional o generalized). Can be?

I know this is an old question however at this moment you still cannot CAD link between Ansys and Fusion360 like you can with Inventor or Solidworks. You can send a study from fusion to Ansys however this does not allow you to use the design exploration tools. Depending on model complexity you could import a step file into design space and use that to create the parameters and then use assembly joint in ansys to put your model back together again as you may have to make it a multibody component to allow for the dimensional behavior that you are looking to optimise.

How about ASPECT(https://aspect.geodynamics.org/), which is supported by CIG (Computational Infrastructure for Geodynamics). It's easy to get started , but I haven't use ASPECT for subduction initiation. And I think you could have a brief look about it , I hope it's useful to you (https://github.com/geodynamics/aspect).

Hi,

In any set-up, there are deep-seated areas where large relative errors are recorded after simulation; perhaps, this account for the observed inhomogeneity in your result.

Endeavour to reposition the source, redefine the source location in terms of (x, y, z) with the target distribution size or area in mind. Take note that homogenous distribution is short range, so locate your source close to your target area of interest.

I hope you find this suggestion useful.

Best regards,

Olaseni M. Bello.

Check out the answers to this question: https://www.researchgate.net/post/How_to_Mn_based_metal_atom_parameter_add_to_autodock, they are also valid for other ions that are not recognised by default.

get the parameter file from http://autodock.scripps.edu/resources/parameters/AD4_parameters.dat/view and follow the instructions kindly provided by @Nur Aqilah Zahirah Norazmi

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Dear Prof. Osman Eroğlu,

It can be modeled with each ring. Also, the lattice of the rings can be 0-360.

I wish you good studies.

Best regards

Try to click "Cobine into single part - > Merge soild regions" when you import your sat file into the part modulue of ABAQUS. I had the same probelm today and fixed it with the strategy.

Devorshi Bhattacharjee Under COSMOL, in the Mesh ribbon toolbar (Windows), select Mapped from the Generators>Boundary () option. Choose Mapped from the Boundary menu () (3D components) from the Mesh contextual toolbar (macOS and Linux) or click Mapped (2D components). Mapped may be selected by right-clicking a Mesh node.

Hi Mir Aamir Abbas,

I'm sorry for the late response. I was trying to solve it. Basically the main problem was that despite my surfaces having a hemispherical geometry, contact was not well established. This was regardless of having a mesh fine in the zone of contact.

To solve the problem, I had to smooth the surfaces in contact, which allowed to obtain credible results.

The replacement {x = x', y = y' + ax'} causes the surface to deform. This change of coordinates represents a Galilean motion. This replacement preserves the total curvature of the surface, even the Euclidean total curvature.

Good luck with your research.

Hi,

I have a similar problem.

Did you succeed in finding a solution?

Thank you

Well, I don't know that much about the effect, but you will access to some displacement variables on the moving mesh (https://doc.comsol.com/5.5/doc/com.comsol.help.comsol/comsol_ref_deformedmeshes.25.05.html), and they will give you the plate displacement, so you should be able to set up a force on a boundary which is a function of this plate displacement.

Maged G. Bin-Saad I got it.

Thank you so much sir.

Hi Behnam Ordoubadi

Have you found a solution to this that you tried and works?. I am in similar boat with slight variation, I would like to just partition and assign a different material to my step file. However abaqus is not allowing me to partition.

Kind Regards,

AM

Thank you Ahmed Al-Manea , Kristaq Hazizi and Erfan Rahimi so much. I apologise for such a late reply . All of your answers are valuable towards solving my problem.

Well , I managed to overcome this problem simply by reading the case file and data file in stand alone fluent solver and changing the boundary conditions(tail gate height) each time.

Of course, the wave equation, through the boundary conditions that define the surface and its properties.

Recursive vs. one-step calculations are of little concern with current computer resources and readily available software. The bigger issue arises from the fact that these two methods solve the same separable differential equation, but using different assumptions when separating the variables before integrating. This means that the two different methods handle some things differently, like implicitly/explicitly averaging properties, heat transfer coefficients, etc. You should consider EPRI TR-107397 (Service Water Heat Exchanger Testing Guidelines). The principal author of 1997 version is Jeffrey Rabensteine of Power Generation Technologies, here in Knoxville. The 2015 version was updated by Lindon C. Thomas, who is a friend and also lives in Knoxville. Dr. Thomas is a renown authority on the P-NTU method and wrote a textbook covering the subject https://www.amazon.com/Lindon-C-Thomas/e/B001HOVPI4

Hi, if you used Ansys SpaceClaim for geometry, then just use share topology between regions you have. the mesh would be conformal automatically.

It is necessary to define the parameters which are in your formula Ff=A/Lb² because in this form Ff is not dimensionless.

Usually, the following parameters are defined for the watershed:

1. Form factor: Watershed Area/(Watershed length)² = A/L², Value < 1

2. Shape factor Bs : (Watershed length)²/Watershed Area = L/A², Value > 1

3. Elongation ratio: Diameter of the circle of watershed area / Watershed length = 1.128A^0.5 /L, Value < or equal to 1.

4. Circulatory ratio: Watershed area/Area of the circle of watershed area = 12.57A/P², where P is the watershed perimeter, Value < or equal to 1

5. Compactness Coefficient: Watershed perimeter/perimeter of the circle of watershed area = 0.2821P/A^0.5, Value > or equal to 1.

Regards

The shear stress can be calculated using the formula, dynamic_viscosity*shear_rate (mu*(vx+uy)).

Nils Wagner Here's a sample job that I created, which should be enough to understand the situation. There are 3 steps with loads (Step-1, Step-2 & Step-3) and 2 dummy steps (Step-1_D & Step-2_D) which only exist to deactivate the loads from the previous step.

This is not the actual model that I am working on, since I don't think I am at a liberty to share that. But the problem is exactly the same. Here the loading is in 3 different directions, which need to be evaluated independently of each other. To save on computation time, I am trying to do them as different Steps in the same analysis rather than create a separate analysis for each direction, but it does not seem to be working out very well so far.

Please let me know if you would like any more details.

Thank you Mr Zaid for your answer

you could also try my software

1. We know that nature of bulk materials and nanoscale materials. Bulk material has been large and smaller crystallite size, but nano materials having unique nature. Although nanomaterials exist 10-100 nm range, that’s why different geometry of same nanomaterials have different photo-absorption and harvesting capacity.

Dear omer,

Watch this video it may help you

Best regards

Used the Laser Scanner software

Yes kittidhaj is right... Geometry is causing a issue

Have you figured out the solution? If yes please share it. I am stuck with the same problem.

I presume you're using some software you didn't write but got from someone else and you're seeking an answer to a runtime error? If that is the case, we would need to know what software you're referring to.

The projective plane satisfies the following axioms:

A. Any two distinct points are contained in a unique line.

B. Any two distinct lines are intersected in a unique point.

C. There exists four distinct points no three of them are collinear.

Ok - You should specify the name of isomers with point gr symmetry - For eg -https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwi0r4eYi9z1AhXkmeYKHUxADwAQFnoECDcQAQ&url=https%3A%2F%2Fwww.mdpi.com%2F1420-3049%2F17%2F12%2F14588%2Fpdf-vor&usg=AOvVaw3t7ufKVg6OZnLdhdvZpjaw

Hi, I am not used to Q-Chem and RI-MP2 methods. But I have found several techniques to improve convergence on this page: https://manual.q-chem.com/5.3/sect_convergence.html

In general, it is useful to look at the last energy values of the SCF procedure. If the energy oscillates, maybe some damping is enough to favour the convergence. If the energy always decreases and does not oscillate (a pare from rare cases), maybe you should increase the maximum number of steps.

I found some details on how to deal with damping on Q-Chem here: https://manual.q-chem.com/5.3/sect_damp.html

I hope this may help

Best regards

Take a look at this:

Editing and deleting questions is well described topic at R^G Help Center page:

For atoms closest the metal, do not use gaff directly. instead of it, generate new atom type. Most Of the time this will solve your problem.

Dear Sidiq Setyo Nugroho,

Yes you can do it via 2D or 3D geometry sketching via magnification of its total shape for its wings geometry. Some related literature is here :