Oh my GOD! I cannot even think how on earth I would have understood these materials if I had not found your channel! THANK YOU SO MUCH 🙏🙏🙏🙏🙏

The power of explanation. I would love to have this guy as my course instructor

@vineettiwari5027

3 жыл бұрын

When he will be your course intructor may be you wont like him🤣😛😛

@killua9369

3 жыл бұрын

@@vineettiwari5027 I will never not like him! He explains things like a king ☑

@vineettiwari5027

3 жыл бұрын

@@killua9369 I know. He teaches great . I have watched almost all his videos. Just kidding buddy😁

@engineeringsimulationstudi1404

2 жыл бұрын

it looks good .. check this also kzread.info/dash/bejne/h6Nlo5ehc8vQldY.html

@adithyarajchoorikat9904

7 ай бұрын

He has an udemy course on the same topic. CFD

My thesis defense is next week and this is immensely helpful for prep work. THANKSSSSS !

@engineeringsimulationstudi1404

2 жыл бұрын

it looks good .. check this also kzread.info/dash/bejne/h6Nlo5ehc8vQldY.html

Thanks a lot . I waited a long for this and finally its here. Love u Aidan.

Dr. Aidan, I found your videos very resourceful and interesting. Thanks for sharing :)

Fantastic talks - really appreciate the time that you obviously put into these. I've been using them to get up to speed as a neophyte CFD analyst, and I appreciate the way that you stress what things mean over just the math!

Once again, fantastic. Thank you so much for these extremely insightful and well laid out slides and videos.

What a clear and brief explanation, thank you!

Thank you so much. I've been trying to get into CFD and these videos really help me to understand how everything fits together.

Your explanation was easy to understand, and catch the key points. Thank you very much!

Thanks for your kind sharing ! Take care at this tough period of time :)

Very nice and smooth explanation. Thank you for your efforts.

This channel is a gem!

Thanks a lot for sharing Aidan. You're the best

extremely helpful video. i've been only able to get convergence in my model using k w SST. i needed to add turbulence and energy dissipation.

You are an excellent teacher. If you ever end up in Academia your future students will thank you. To round out your talks on turbulence models, I would suggest discussing: DNS, LES and DES. Of these DES is the most practical but understanding all three really adds to a person's fundamental understanding of turbulence.

How did I miss you all those years in KZread!!!!?????

Hello mr Aidan, Thank you so much for your videos. I have been curious for CFD since I was an undergrad student. Its amazing how elegant and simple are your explanations. Thank you for your videos and keep on the good work!

@engineeringsimulationstudi1404

2 жыл бұрын

it looks good .. check this also kzread.info/dash/bejne/h6Nlo5ehc8vQldY.html

As always an awesome explanation Prof.

Very powerful speaking, I learned very much, thanks!

You're going to be big. Keep this up!!

You are the genius. Great to learn lectures from you 🙂

Hi Aidan, Many thanks for the wonderful videos on the basics of CFD. I successfully defended my PhD thesis and your videos were immensely helpful. Keep up the good work. Best regards

@engineeringsimulationstudi1404

2 жыл бұрын

it looks good .. check this also kzread.info/dash/bejne/h6Nlo5ehc8vQldY.html

Thanks a lot for the lecture! The information will help me to perform well at the presentation.

That was really fantastic and amazing explanation, and I used it for my present in Turbulence course.

@engineeringsimulationstudi1404

2 жыл бұрын

it looks good .. check this also kzread.info/dash/bejne/h6Nlo5ehc8vQldY.html

Great explanation. Being in a preliminary stage of learning about CFD, these videos clarifies the concepts very well and quite intuitively. Great work. Thank you very much.

@engineeringsimulationstudi1404

2 жыл бұрын

it looks good .. check this also kzread.info/dash/bejne/h6Nlo5ehc8vQldY.html

Excellent man! thank you so much, is very useful and easy to understand.

Excellent explanation! Thank you!

Excellent lecture Aiden, thanks very much !

Fantastic and amazing explanation

thanks for the crystal clear explanation!

Thanks again for the brilliant lecture🤩🙏👍

Good explanation of the K-w model. Please provide an explanation of the different K-w models' respective applications. Thank you

Love you Aidan!!

The best channel to know the magic behind CFD For an application engineer like me this channel is safe hevaen

Amazing! Thank you!

Thanks a lot. You're a great teacher, in the true sense of the word.

@engineeringsimulationstudi1404

2 жыл бұрын

it looks good .. check this also kzread.info/dash/bejne/h6Nlo5ehc8vQldY.html

Great video and brilliant explanations. I really enjoyed it. Thanks!

@engineeringsimulationstudi1404

2 жыл бұрын

it looks good .. check this also kzread.info/dash/bejne/h6Nlo5ehc8vQldY.html

Thanks from Colombia men, it helped me

Very good explanation, thank you!

thanks for the video. It's really good!

Thank you Thank you very much dear Aidan 😍

I found this talk very usefull!

Love your explanation!

These videos are great !!!!

Thanks Aiden for all these great videos with excellent clarity on explanations. The only thing I would say maybe to add more value is annotating the slides using a digital pen while you explain. This may help to draw the attention of the audience even more. Thanks again for your great contribution towards teaching the most complicated concepts in the field of CFD.

@fluidmechanics101

2 жыл бұрын

That's actually a really good suggestion. Thanks Venkata!

i rarely leave comments but i just wanted to say these videos are amazing. You have a way of explaining things that is rare in people. Your style and methods are something i'm going to use when explaining CFD concepts.

@fluidmechanics101

Жыл бұрын

Thanks Austin, that really means a lot to me

@j121212100

Жыл бұрын

@@fluidmechanics101 i'm using a 12mm tetrahedral mesh with k omega model with an inlet turbulence scale of 20mm and energy dissipation of 2% in my inlet velocity field. i'm restricted in my total mesh size by my memory constraint of 8GB so my total volume is not quite as large as it should be for the duct of 250mm radius the overall space is 1000mm radius cylinder. with a depth of 5000mm. Will i get results that will yield insights for tuning the duct profile? At 300 iterations i am seeing the emergence of detached flow in the trailing section so i see that as a positive sign. I think i need another 300 or 400 iterations before all residuals are below 0.001

@fluidmechanics101

Жыл бұрын

As you are limited by memory, you can only do the best that you can. I would just accept that your mesh is under resolved and look for qualitative flow features and stick to comparisons between different cases. You can still get good understanding from CFD, even if your results aren't accurate. This is really what CFD is good for: understanding, not prediction 👍

Great explanation 👍

It would be more interesting if you could give a lecture about the v2-f turbulence model.

Very helpful, thnks a lot!

You are a God! Thanks a lot!

Thank You Very Much, I felt very comfortable the time I switched on your lecture, My entire work of research is dependent on these models, But at this point in time, literally, I don't have any idea of these models and their usage. I am way too late for my research proposal. I am trying to connect things together. So I am trying to reconstruct everything to get a better understanding, I just found your channel, don't know about other videos yet, have to watch them all, In case if I don't understand then you can help me out, One thing I have to ask you to make is a video on simulations in CFD Ansys on a sample of models

Realizable k-epsilon model with enhanced wall treateament is also useful for aerodynamics applications. Great video.

@leonriccius2684

3 жыл бұрын

would also love to see a video on that one

Thank you very much ! you are such an inspiration for me the way you explain things so easily ! It really made me to give you a feedback. I would just like to know a bit more on tricks or tips to select the ideal turbulence model for different geometries.

@engineeringsimulationstudi1404

2 жыл бұрын

it looks good .. check this also kzread.info/dash/bejne/h6Nlo5ehc8vQldY.html

thanks mate, your explanations are amazing.

@engineeringsimulationstudi1404

2 жыл бұрын

it looks good .. check this also kzread.info/dash/bejne/h6Nlo5ehc8vQldY.html

dr aidan ı wish you were a teacher in my school you are the best

Thank you for the video

These videos are great :)

very easy and useful.

Thank you Aidan for the nice explanation! Another rather popular RANS turbulence model is the KSKL (or k-sqrt(k*L)) model. It is quite popular for maritime applications. The advantage is a less sensitivity to the value of y+ at the wall and an easier iterative convergence because you don't need to specify a very large value of omega at the wall (especially useful at high Re when the cell size must be extremely small and so omega at the wall becomes huge). It could be worth a video about it. :) An interesting thing would be to see how these turbulence quantities (k, epsilon, omega, mu_t, production) are distributed in the flow (for instance in a boundary layer) to yield the correct mean flow solution. In this way one could develop a sort of "feeling" about where a particular quantity should be large or small, so one could better evaluate whether the CFD solution makes sense or not. Thank you again!

@engineeringsimulationstudi1404

2 жыл бұрын

it looks good .. check this also kzread.info/dash/bejne/h6Nlo5ehc8vQldY.html

Hey man, I have been watching of lately a lot of your videos, you really inspired me to try out a bunch of CFD little problems. I want to pursuit a career working as an aerodynamicist, I'm currently studying mechanical engineering :)

@fluidmechanics101

3 жыл бұрын

Awesome!

@Michallote

3 жыл бұрын

@@fluidmechanics101 thank you so much! By the way I would like to know if you could make a video on the algorithm that XFoil uses for 2D flow over airfoils

@fluidmechanics101

3 жыл бұрын

XFOIL is awesome! I am a big fan. It uses a classic 'panel Method' which is a bit outdated for fully turbulent flows. But it's treatment of natural and forced transition on transitional aerofoils is really good! I might make a video one day, it is a bit niche to aerodynamics though 😄

Thanks for the video

Man, I'll pay you my tuition fee and you come teach me. I wish all our lecturers could pass on the knowledge like you do. Wonderful work! Plus, I appreciate that ,thanks to you, I can now work on my dissertation with confidence

@martita505

Жыл бұрын

I have 1 question as it is hard to find exact data. Ansys 2022 has the Transitional k-kl-omega model. Is it the same as k-omega sst? There is also Tansition SSt one as well. A bit confusing. Mind giving some clarification on that? Thanks :)

@fluidmechanics101

Жыл бұрын

I haven't checked out the manual but it sounds like they are different models (but either could be used for modelling transition to turbulence)

@Raphael4722

Жыл бұрын

@@martita505 No they are not the same. You can find the k-omega SST model as one of the k-omega model options in Ansys.

awesome mate

Thank you!

Great video, please do one on DES, thanks

you're the MAN

Thank you so much for such a nice presentation! Would you mind to clarify with regard to Free Stream Turbulence, please?

Great lecture sir please make a good series on large eddy simulation as no one talks about it so frequently it would be great

@engineeringsimulationstudi1404

2 жыл бұрын

it looks good .. check this also kzread.info/dash/bejne/h6Nlo5ehc8vQldY.html

Aiden brilliant explanation!!...one doubt though ..you mentioned that this model is good when having adverse pressure gradient/ mild seperation...what if we have a very large seperation??? What turbulence model do we go for???

amazing lecture!!! I just have one question: why does the k-omega formulation does not need wall functions? if we can convert between omega and epsilon freely, why this formulation does not use damping functions?

Well explained gud 👍

Firstly, Thank you Aidan for the videos. It is very beneficial. Keep going. Best wishes. I have a question, Is Y+ value immaterial for SST-kw model? Can you explain. Thanks in advance.

Wow! So useful :) Could you please consider making a video on types of separation and which model is best suited for which type of separation?

@engineeringsimulationstudi1404

2 жыл бұрын

it looks good .. check this also kzread.info/dash/bejne/h6Nlo5ehc8vQldY.html

Hi Adian, I would like to point you one correction at 10:30. It should be Pk.. not Pe. Remaining all is good and wonderful material.

@fluidmechanics101

3 жыл бұрын

Well spotted! Thanks 😄

Thank you very much Aidan! Could you do a video about the v2f model sometime in the future? Greetings from Brazil

@fluidmechanics101

4 жыл бұрын

Yep, its on my list!

Muchas gracias por tu video, dejó mi comentario en español para que veas que te seguimos desde muchas partes. ¿Donde encuentro el video sobre el modelo k-e que mencionas?

Phase change model, in particular Lee's Model for evaporation & condensation

Just finished my degree at Imperial in Aeronautical engineering. I really wished I'd seen these videos earlier!!! Absolutely fantastic, and very clear and consistent. One very minor suggestion could be adding a box to your slides and then overlaying your video into the box post-production? Avoids you having to cover any information on your slides... Thank you!

@killua9369

3 жыл бұрын

Do you have a twitter account? I have some inquires about Imperial; my twitter is @Killua_xy please contact me

@engineeringsimulationstudi1404

2 жыл бұрын

it looks good .. check this also kzread.info/dash/bejne/h6Nlo5ehc8vQldY.html

Now everything falls into place :)

Thanks

Thanks! very informative, it would be great to go through the non-linear eddy viscosity models since you are creating videos around the RANS models, it's just a suggestion. It might be also worth looking at the weaknesses of linear EVMs, in particular within turbomachinery applications when high curvature and rotation exist in the flow filed, hence Curvature Corrections, etc. again just another suggestion.

@fluidmechanics101

4 жыл бұрын

Yep, there is lots to cover. I want to get through all of the turbulence models eventually 😊i am trying to decide whether to go for LES (and its variants) first or go for NLEVM and maybe Reynolds stress. I will bare this in mind! Thanks for your suggestion

@seyedsoroshmirfasihi3267

4 жыл бұрын

@@fluidmechanics101 That would be a very useful archive to have. Also, you are right, since the main idea of the NLEVM is taken from the RSMs, I think it is better to start from the RSMs and build upon that.

@engineeringsimulationstudi1404

2 жыл бұрын

it looks good .. check this also kzread.info/dash/bejne/h6Nlo5ehc8vQldY.html

Big thanks for video, this is awesome. Will you make video about Reynolds Stress Model (RSM) in future?

@fluidmechanics101

2 жыл бұрын

Yes, hopefully if I get time 😅

I heard about Lattice Boltzmann instead of Navier Stokes but dont really get it. If you want an idea for a next video ^^

Hi Aiden! I was comparing the equations writed down in the slides with the ones on the NASA website, it seems that the SIGMA_k and SIGMA_omega coefficients are placed in a slightly different way; in particular, they are at the numerator and SIGMA_omega is used instead of SIGMA_k within the omega equation. I think that the same thing also happens in the k - omega SST video. Please, let us know if there is a little typo or the adopted coefficients have simply a different value. Big thanks for these beautiful resources!

@fluidmechanics101

Жыл бұрын

I would always go with the NASA page. The page exists exactly for this reason ... to check for typos in CFD user manuals and KZread videos 😅

Is it possible to use your presentation in the form of screenshots with mentioning your name?

Excuse me sir, you said that practically the dissipation rate (epsilon) has the opposite behavior compared to K... but with Taylor hypotesis (epsilon=K^(3/2)/L), K and epsilon have the same behavior... or not? Thank you.

Thank you Aidan!! This was the video I was waiting for so much :D What do you think on a video about turbulent mass transfer and wall functions?

@engineeringsimulationstudi1404

2 жыл бұрын

it looks good .. check this also kzread.info/dash/bejne/h6Nlo5ehc8vQldY.html

Hi, Dr.Aidan, thank you for your interesting introduction to these RANS models, could you please share some of your ideas about RSM kinds of the second-moment closure model like this video. Thank you for your work.

@engineeringsimulationstudi1404

2 жыл бұрын

it looks good .. check this also kzread.info/dash/bejne/h6Nlo5ehc8vQldY.html

THANKS SIR

MVP

I LOVE YOU METROMAN

Thank you so much for your video!!! You mentioned in the video (time 15:30) that k-epsilon model requires damping function for solving the boundary layer while k-omega doesn't require any damping function. This difference explains why k-omega is better for cases where resolving boundary layer is essential to account for the adverse pressure gradient. Some time ago, I tried to study why k-omega can resolve the boundary layer without using damping function. However, it is still unclear to me since I couldn't find any reference with a good explanation on it. May I learn from you about that?

@mateusalves9558

4 жыл бұрын

I would like to know that too, excelent question and fantastic video from Aidan again

@fluidmechanics101

4 жыл бұрын

I think this is explained in the original wilcox paper. It is because the behaviour of omega is relatively smooth all the way through the log law and viscous sub layer, while epsilon has a peak in the buffer layer. This makes it tricky to define a consistent function for epsilon that is smooth all the way to the wall. I would have another look at my video for ‘epsilon wall functions’ and you can see the variation of epsilon close to the wall. Good question though! It is definitely not very clear

@mateusalves9558

4 жыл бұрын

Thank you for the reply, and I have saw these videos so many time kkkk.

@engineeringarts4509

4 жыл бұрын

@@fluidmechanics101 Thanks for your reply. I revisited the Wilcox's book "Turbulence modelling for CFD". He tries to analyze the asymptotic behavior of omega. According to my understanding, he analytically finds out the asymptotic values of k and omega at wall surface (in viscous sub-layer), and then analyze towards into the log-law sub-layer. Through fitting into the standard law-of-the-wall formula for log-law sub-layer, the analytical values of the formula constants (B and n)are evaluated. He compared the formula constants for different sets of k-omega models against the measured formula constants (B=5 and n=2). He points out that his k-omega model gives the fairly closed values, which argues that damping function is not required for k-omega model, and also the good performance of his model. Hope my understanding is correct! But, frankly speaking, I am not in a good context with the procedures in his proof. Pls kindly share your view, if any.

@engineeringsimulationstudi1404

2 жыл бұрын

it looks good .. check this also kzread.info/dash/bejne/h6Nlo5ehc8vQldY.html

Thank you for your kind explanation! Also, I have a one question. Video said that k-w model does not need damping function. Then, does it mean that k-w model use empirical coefficients instead of damping function in the viscous sub-layer?

@fluidmechanics101

2 жыл бұрын

Essentially yes ... The empirical coefficients tune the model so that it has the correct asymptotic behaviour as it approaches the wall

very nice talk. In practice Eq 9 is what is used in the k-omega model but I think the omega transport equation as derived from (or equivalent to) the epsilon transport equation should have another term that is proportional to (rho/omega * grad k times * omega) which is zero only for homogeneous flows.

@fluidmechanics101

Жыл бұрын

Thanks for the pointer. Do you have a good reference for the additional term? I would love to have a read and check it out

@robertopaoli7836

Жыл бұрын

@@fluidmechanics101 Pope "Turbulent Flows", chapter 10. The exact transport equation for omega (implied by epsilon) is Eq. 10.99, which reduces to 10.94 with very minor assumptions and finally to 10.93 (i.e. your Eq.9) fro homogenous turbulence

@fluidmechanics101

Жыл бұрын

Yes that's the one. Thanks Roberto

@robertopaoli7836

Жыл бұрын

@@fluidmechanics101 A pleasure. Again, your lecture is very clear

Can you talk about SAS and DES?

Excellant video.Would be really great to understandd eulerian multiphase model.

@fluidmechanics101

4 жыл бұрын

I think i have a video on multiphase flows 🙃 check it out!

@totaloverdose3591

4 жыл бұрын

@@fluidmechanics101 I'm really sry.Did notice it later.Was awesome!

Why not start making videos on LES simulations? Since, they are the state of the art now. In addition to that, I must say, your videos have just the appropriate mixture of math and physics. Keep making more :)

@Fluid Mechanics 101 So my first question, you might have come across the turbulence viscosity issue in CFD Simulations, for instance if you specify a turbulent viscosity ratio for which there is no any hard and fast rule - you have to take the values between 1 and 10. For instance if turbulence intensity is 1% you would be taking viscosity ratio betwern 1-3. But during the simulations this viscosity becomes limited on the mesh and solver gets exhausted. Some CFD people believe that increasing the limit for this viscosity won't give the realistic data in the end since the viscosity is already high that computational domain is unable to withstand. And some say it happens due to poor mesh quality. Why do you think this issue appears and what's the best fit to this? P.S: Sorry if my question is a bit off-topic.

@hrkalita159

3 жыл бұрын

Do anyone cares😂🤣😂🤣

@fluidmechanics101

3 жыл бұрын

Have you tried looking at the solution itself? If the viscosity ratio is sensible in the areas that you care about, and the viscosity ratio is only too high in a few bad cells then you can be happy with your solution 🙂

At equation 6, shouldn't the production term be P_k instead of P_ε?

@rishi0299

3 жыл бұрын

Yes