LS-DYNA TUTORIAL 19: Sloshing Inside a Tank with ALE method

[@CaptainMyron]

Thank you for these tutorials i am learning LS-dyna for my phd, you have been a huge help.

[@AmeenTopa]

You are welcome and all the best for you PhD! Please check my research articles and cite them if any is related to your research 😁😁

[@FlowDragz]

@@AmeenTopa Would you still have to use multi material ALE if it was just water inside the tank or would you be able to use 1 point ALE (ELFORM = 5)?

[@AmeenTopa]

@@FlowDragz if it is fully filled tank, yes, ALE = 5 should be fine.

[@FlowDragz]

@@AmeenTopa If you use ELFORM = 5, do you still need to use a certain keyword like ALE_MULTI-MATERIAL_GROUP?

[@FlowDragz]

@@AmeenTopa Do you still need to use a keyword like ALE_MULTI-MATERIAL_GROUP for ALE = 5?

[@Garcia....]

Easy to understand, explain too clear, You are an excellent professor! Thx!

[@AmeenTopa]

Glad it was helpful! Kindly share my videos so more people can learn from it! :)

[@ДимаЕвтюнин]

Thank you! Your video very informative and helpful for all engineers

[@AmeenTopa]

You are welcome! Please share this video so more people can learn!

[@dududulcap458]

Excuse me. Do you know cohesive elements? I set my ice with cohesive elements and use a rigid part to impact on my ice. My question is when I set an Eroding single contact to simulate ice self-contact. My SPC boundary condition on ice just make no sense, ice cubes spread out directly after impact. Can you give me some advice? Thank you, your videos are very helpful for my article.

[@AmeenTopa]

@@dududulcap458 yes, I have worked on ice modelling with cohesive elements. What's the problem with your model?

[@abrahammorenoreyna2758]

I agree!! you are an excellent professor!! Thank you!

[@AmeenTopa]

You are very welcome! Please share my videos so more people can follow

[@rayb4271]

Hi Ameen, Thank you so much for the helpful video! I followed all the steps but when I ran it, the ALE water does not move at all, even though the tank moves perfectly fine. I am using the 2024 version of LsDyna. Do you know of any things that may have changed since 2020 that would be causing this? Thanks!

[@AmeenTopa]

This shouldn't be a problem with the solver. Please make sure that the steps are followed correctly, especially the following keywords: *INITIAL VELOCITY GENERATION *ALE REFERENCE SYSTEM

[@dakshitha92]

Very easy to follow, thanks for sharing. One question. Why do you want a reference co-ordinate system?

[@AmeenTopa]

In the previous example (sphere drop on water), we didn't need it because the ALE mesh was stationary. Here, the tank is moving initially then it stops. That's why we need the reference coordinate system so that the ALE mesh will follow the motion of the tank.

[@vedantjoshi6191]

Hi Ameen. Very nicely explained! I just had one question though, when I run the simulation for a longer period of time, I can see that the tank eventually fills completely with water after sloshing (hence volume of air & water aren't conserved). Am I missing something, could you let me know what the issue could be. Appreciate it!!

[@AmeenTopa]

The air mesh should be extended beyond the tank.

[@徐鹏飞-k5f]

Hi Ameen.What a geat job u r doing ! In the video tutorial, I saw that you first copied shell of the liquid container, then cleared the shell at the original position, and moved the copied shell back to the original position. Why don't you need to merge again here?I mean that there are dup nodes at the junction of air and water with the shell?In addition, I would like to ask you how to solve the dynamic analysis of full liquid container(without air) under the action of earthquake? We look forward to your advice and help. I felt I could solve this problem with Fliud80 in ANSYS.Thanks U!

[@AmeenTopa]

Hi there, The reason why I copied the tank is because I don't want it to be merged with the air and water mesh. Lagrange mesh and ALE mesh shouldn't be connected with each other. Regarding your second question, you can input the acceleration from the earthquake using BOUNDARY PRESCRIBED MOTION RIGID if your tank is rigid or PRESCRIBED MOTION SET if your tank is deformable. I can give your further support on this matter as I am doing research about sloshing too. But only if there is a research collaboration between us....and of course we use LSDYNA for the simulation....

[@徐鹏飞-k5f]

Thank you for your answer.I see what you mean. In addition, I am sorry that I made a mistake in my expression. I don't mean merge,actually what I mean is whether normal degrees of freedom of dup nodes need to be coupled ?They are needed to be coupled when using ANSYS Fliud80, so I put forward this question. I thought that LSDYNA would do the same.Now I understand through your explanation.Also, for ALE algorithms for full containers, is it ok to remove the air part from your video tutorial?Then do a dynamic analysis using the two keywords you mentioned?Can I get your email or wechat for further contact? Hope to have the opportunity to cooperate, such as co-author published papers and so on.

[@AmeenTopa]

Regarding ANSYS, you can apply the acceleration on all the nodes of the tank. You can model the sloshing with only water. But still you need the mesh of the empty space of the tank. You can declare that space as void. Put your email here and I will follow up in my free time.

[@AmeenTopa]

For simulation of ALE with water and void, check my tutorial ball drop on water.

[@徐鹏飞-k5f]

Thank you! My email:[e-mail] I have implemented FSI simulation using Fluid30 or Fluid80.The dynamic calculation takes the same approach as you said, consistent input, acceleration applied on all nodes.I will do simulation of ALE with water and void then discuss the problem with you.

[@hshay412]

Dude, you are just brilliant! Thank you so much!

[@AmeenTopa]

Glad to help! Please share my tutorials and support me so I can make more and more videos!!! :D

[@diegoarmandogomezmarquez879]

Hello Mr. Topa. Thanks for so many useful tutorials. May I ask you something no directly related to this? When we use ALE eleform 12 (with void) in a thermo-structural analysis, setting the initial condition of temperature for the void part, and after the analysis starts, its temperature falls to 0 no matter which value we set. ANy idea?

[@AmeenTopa]

If you want to see the effects of temperature in air, then it is better to use multi material ALE instead of ALE with void. Because void is just like empty space, which has no material inside it, so it has no temperature.

[@diegoarmandogomezmarquez879]

@@AmeenTopa thanks. I had the same idea. Unfortunately, the eleform 11 multi-material doesn't work with the thermal solver yet. and BTW, your tutorials are more and more amazing.

[@AmeenTopa]

Thanks. Don't forget to share my videos so more people can benefit :)

[@AmeenTopa]

Have you tried change from the default value of AET in SECTION SOLID?

[@抠脚蕉太狼-v6b]

Dear Ameen Topa Do you have a video about blasting? Several blast holes detonated at the same time while driving the tunnel

[@AmeenTopa]

Yes. Check my tutorial TNT Blast on Composite Beam

[@dequan-g2z]

Hello,sir! I would like to ask you that if you can tell me how to conduct the FSI of Air-backed steel plate subjected to underwater explosion? I am confusing that the overlapping area between Lagrangian mesh grid and the ALE mesh grid. Thank you so much!

[@AmeenTopa]

Check my tutorial on TNT Blast on Composite Beam.

[@dequan-g2z]

@@AmeenTopa Thank you so much!

[@AmeenTopa]

@@dequan-g2z no problem!

[@furkansaruhan568]

Dear Amen, thanks for everything

[@AmeenTopa]

You are welcome!

[@roshanthapa4415]

Thank you very much for this wonderful tutorial. But, when I compiled, I got the warning that the " Input contains 2 ALE parts", warning: "There are 2522 nodes shared by both ALE and LAG parts." and the error message: "ALE coupling interface is unsupported - ignored". I got the same warnings and errors even when I ran the rectified .k file in your description too. Do you have any idea to overcome this? Thank you.

[@AmeenTopa]

It maybe that you have a problem with your solver. Make sure to run with double precision solver and chose the latest version. Regarding the warning, it is fine and you better separate between the ALE and Lagrange parts. Use transform and translate tool to make a copy of the Lagrange part.

[@SherylDolot]

Hi Mr. Topa Just want I followed all the steps that you do on the video but mine is not waving at all the tube is just moving forward and backward but not the water inside. Do you have any idea why is that happens?

[@AmeenTopa]

Make sure you show the ALE 'fluid' parts when you are post processing. Hide the solid parts.

[@SherylDolot]

I just did what you have said but nothing happened to the fluid sir, still not waving @@AmeenTopa

[@AmeenTopa]

@@SherylDolot make sure that the top half and the lower half of the ale mesh are connected.

[@SherylDolot]

hi Sir, do you have the old .k file for this toturial? Can I have a copy of that sir? @@AmeenTopa

[@SherylDolot]

as of now sir it doesn't make a wave at all

[@ahdshsah4869]

HI Ameen, Thanks again for the nice video, it definitely helps for the physical problem I am currently facing. Could you please kindly answer one question, For the the linear polynomial coefficient you used for EOS in the air domain ; and the coefficient you used in for Gruneisen EOS equation in the water domain, could you provide the literature/guide of how to finding these coefficients? I have checked your early ball drop to water tutorial, the water was model in polynomial EOS and the coefficient are different from what you used in this tutorial. Thanks a lot. Zhemin Cai

[@AmeenTopa]

Hi Cai, There is no directory where you can find these coefficients. The only way is to look in the literatures. If you look and compare both examples, yes the coefficients are different, but also the NULL material definition. The EOS coefficients depend on how you define MAT NULL. You can check here for more examples for water simulations: www.dynaexamples.com/ale/sloshing www.dynaexamples.com/ale/intermediate-example/wavestructure www.dynaexamples.com/sph/intermediate-examples/wavestructure The wave structure examples were validated against experimental work. So I believe you can trust their input :)

[@ahdshsah4869]

Hi Ameen, Thanks a lot for the detailed explanation and dynamore example, really helps, appreciated😄

[@AmeenTopa]

@@ahdshsah4869 No problem. If you got any questions, feel free to ask. Just for your note, I am always open for research collaborations :D

[@ahdshsah4869]

@@AmeenTopa Hi Ameen. That is Great, the content left on my project has will focus on two parts: (1) Fluid slosh simulation in a baffled chemical transport tank, I have run a set of model in Ansys fluent and finished the early stage simulation, but short duration peak force was observed, I assume it should come from the VOF numerical method and the solver can not handle the sharp separation on the wave with short duration, that is why I want to try SPH/ALE method on dyna (2) Simulate polymer powder movement, heat transfer and phase change inside a rotating tank, For this part, Dyna is the only tool I found can handle this complex physics, I still have one year left for this project so hopefully I could solve it. I am from UNSW in Sydney, Below is my linkdin profile" www.linkedin.com/in/zhemin-cai-4a67a5112/?originalSubdomain=au", my unsw email address is "[e-mail]". Thanks a lot for your video and help, very happy to collaborations.

[@AmeenTopa]

I have looked into your LinkedIn profile and had a quick look at your previous work from ResearchGate. I’d say that you have done very good work. I am Ameen Topa, a Research Scientist from PETRONAS University of Technology, Malaysia. My core research is impact engineering and fluid structure interaction simulations. Looking forward for this collaboration.

[@giridharpotharaju2713]

thank you, sir, for such a nice video. I am also trying to model liquid storage tank subjected to seismic excitation, but I am facing some difficulties in modelling part like we have to use initial volume geometry. If possible, please do a tutorial on this topic. it will help me a lot

[@AmeenTopa]

Thank you! I am glad you liked my work. With regard to your request, unfortunately I cannot make it due to my time constraints. However, if you are interested in a personal consultation session, please contact my team and they will arrange.

[@giridharpotharaju2713]

@@AmeenTopa yes sir how to contact your team. can you give details for that

[@AmeenTopa]

@@giridharpotharaju2713 sites.google.com/view/topacademyofficial/about-topacademy

[@dicoga2]

Hi Amen. Thank you for these ALE Method videos, very helpful for my Final Degree Project. Have you worked with underwater explosive simulations with ALE Method? Could you upload some tutorials on them? Thank you!

[@AmeenTopa]

You are welcome. Regarding the underwater explosion, I have shared an example with SPH for underwater explosion. From there you can take the material properties of water and explosives. I have uploaded two tutorials on ALE so I think you should be able to convert the SPH file to ALE file.

[@付世博-v8r]

I have used ALE method to simulate air explosion before, please leave your email address if u want to communicate.

[@dicoga2]

@@付世博-v8r [e-mail] Thank you!

[@twinpa911]

Thank you so much for nice video. I believe it is helpful to build vehicle door and air model under side impact to define pressure level. The LS-Dyna job 'Sloshing_Ex.k' is well completed in smp R11.1 WINDOWS X64. Tank and ALE are moving together, but ALE air and water are not shown sloshing. What do I need to check for input file to see ALE sloshing?

[@AmeenTopa]

You are welcome. Make sure to display the Fluid (ALE) parts not the solid part.

[@shout_gopchang]

I have a question.. Why do you use *ALE_REFERENCE_SYSTEM_NODE? If we don't use the keyword, what happens?

[@AmeenTopa]

The ALE mesh will not move forward with the tank. You can try and check yourself.

[@yashchordiya5963]

Amazing video!

[@AmeenTopa]

Thanks! Please share my videos so more people can learn! :D

[@AccelifeLiam]

thank u so much for ur tutorial brother ameen，but i don't understand why the normal of the tank has to be reversed

[@AmeenTopa]

This is because of the coupling between the ALE (fluid) and Lagrange (tank). The coupling should be only in one direction (compression only, and no tension).

[@AccelifeLiam]

@@AmeenTopa THANKS

[@jiayueding4314]

How do we define the parameter in EOS_GRUNEISEN or EOS_LINEAR_POLYNOMIAL when it's a polymer instead of water?

[@AmeenTopa]

It depends on what type of polymer. (I assume you are talking about melted polymer here). It is really difficult to tell. You may need a different type of EOS. The only way to find is to search in the open literature.

[@jiayueding4314]

@@AmeenTopa Hi Ameen. Thanks for your reply. I am running my ALE simulation and facing an Error "Negative volume in advection redo cycle". Do you know what causes this?

[@尹小东-l1u]

嗨，Ameen.我来自中国，通过朋友的推荐观看了您的视频。你的视频真的很好，对我现在的论文很有帮助，但是现在有一个问题，当罐体材料是刚体时，结果和你的一样。但是当我把水箱的材料换成001-ELASTIC时，随着水箱的移动，它得到的水越来越多，空气越来越少，直到水箱装满水，有什么问题呢？期待您的回复。

[@AmeenTopa]

Thank you for reaching out. I used GoogleTranslate on your comment because I don't understand your language. You are using MAT ELASTIC instead of MAT RIGID for the tank. Make sure that the material properties are correct. Also, make sure that the ALE domain is larger than the tank, not like my video. In my video, the ALE is only inside the tank which works only with rigid tanks.

[@尹小东-l1u]

@@AmeenTopa Thank you very much for your reply. I'm sorry that Google automatically translated my comments, which caused you trouble. I wanted to use MAT ELASTIC instead of MAT RIGID to get the stress and strain of the tank, but eventually the water got more and more and ended up filling the tank. Do you mean that I need to expand the air domain outside the tank to surround the tank? But it creates a very large air domain.

[@AmeenTopa]

@@尹小东-l1u Yes, you are correct. You need to make the ALE domain larger than the tank. However, you only need one or two layer of elements in each direction. So, the model woll not be very large.

[@尹小东-l1u]

@@AmeenTopa Thank you for your answer. I understand. However, since the inner ALE domain and the outer ALE domain are separated by the tank, can the ALE domain be processed in a common node way? And by the way, can I set MAT RIGID on the tank and then put that pressure on the tank and get the stress? Indirect coupling similar to FLUENT software.

[@AmeenTopa]

@@尹小东-l1u The ALE mesh inside and outside the tank should be connected (shared nodes). However, the Lagrange tank mesh should not be merged with the ALE mesh. If you use MAT RIGID for the tank, then you can apply a load (it will be force, not pressure) using LOAD RIGID BODY.

[@抠脚蕉太狼-v6b]

thank you!

[@saichilla2421]

Very useful video sir, I'm doing a final year project on ls dyna can u help me sir!!?

[@AmeenTopa]

Thanks. Please share my videos so your classmates, juniors can benefit too. Yes how can I help you?

[@saichilla2421]

@@AmeenTopa can you make a video for how to do a static and dynamic analysis (axial crush) for a complex geometry (like cone which is like the cones placed on the road)with the composite materials??? Already watched the video you have done before for that particular analysis (cylinder shell) very helpful started working with that sir but it taking too much time when I use the same process for the cone and alsp ended up with error termination sir!! Can u please help me to get through it!??

[@AmeenTopa]

@@saichilla2421 You can check this video for axial tube crush. kzbin.info/www/bejne/aZ3UlqSPl6atpdE I don't have any videos on composite simulation. I have planning to do one but due to time limitation I haven't done it yet (I am not a full time KZbinr :D )

[@AmeenTopa]

@@saichilla2421 Static analysis will take long time if you are using explicit solver to run them.

[@saichilla2421]

@@AmeenTopa thank you sir for reply that's the video I watched sir many times. can you tell the way to do the same with the cone (closed at one end like halfsphere and open at other end with a section thicknes of 3mm)