Harmonic Acoustics analysis on ANSYS R19.2

[@cemalettintan7067]

Mr. Lee, thank you very much for your valuable efforts.

[@diyextravaganza]

Your channel is great and very informative. Thanks for sharing all this !

[@jiamingzhang4870]

can I use harmonic acoustics apply limited bandwidth Gaussian white noise to the structure?

[@maneeshvardhanreddyinakoll7765]

If we want to find transmission loss for the same scenario then how we have to proceed sir? and thank you so much for your last advice I was able to proceed further in my project😃

[@jonghak.lee_simulation]

Your question is that you want to do an acoustic analysis that calculates the same TL curve as the reference TL curve(For example, the experimental value or other simulation result)? like as calibration between experiment and simulation? Calibrating a TL curve is a bit complicated. You can refer to the calibration example in Ansys optiSLang. However, the challenge is to be able to extract TL values from Mechanical to a txt or csv file. To do this, you need to use APDL commands in post-processing. Also, the PORT boundary conditions must be defined in APDL, as the PORT referenced when extracting TL with APDL commands cannot be used with the PORT of the icon function. To do this, refer to the source code in the Ansys Help > Mechanical APDL > Acoustics Analysis section.

[@stefaniamagnettigisolo5775]

good morning. Please, does someone know what to do when this error occurs: "reference to an object not set to an object instance". It occurs when I try opening Ansys meshing, and I don't know what to do, I cannot understand why it happens now.... please, I am desperate!

[@jonghak.lee_simulation]

Sorry, I have no idea because the error occurred based on various reasons. Please contact to Ansys support team in your country.

[@SURABHISAXENA-os5qe]

run as administrator. it worked for me

[@votongnguyen6104]

교수님 안녕하십니까 보여 주신 동영상을 잘 봤습니다. 감사합니다. 죄송하지만 금궁한 것이 있습니다. mass soure를 어덯게 계산하십니까? 그리고 영구자석의 온도 증가한 경우는 수치해석 한 스피커 음압레벨에 미친 영향이 있습니까? 회신 부탁드립니다. 정말 감하하겠습니다.

[@riccardopenna1]

Hi. Can I use this method if I want to simulate the path of an ultrasound in a specimen without the interaction with air?

[@yangsun610]

thank you so much! really high level! could you do an example of the acoustic topology optimization?

[@jonghak.lee_simulation]

Sorry, I have no experience about it. I thought Ansys does not support acoustic topology optimization. You can use size parametric optimization for acoustic performance.

[@mohankrishna2098]

Hi all, can some one explain why 3D modelling to be chosen for the acoustic analysis can it not be done with the 2D modelling? Can you also help me by mentioning few links where i can study in detail about it. Thanks in advance.

[@jonghak.lee_simulation]

Ansys has 3D and 2D Acoustic Fluid Element types but, Workbench Mechanical application does not support the 2D element. Another way, if you make a 2.5D model(thin 3D model), you can run like 2D analysis. You can refer to the park distance example of Ansys Acoustic ACT.

[@yingliu1455]

@@jonghak.lee_simulation Hi Jonghak, thanks a lot for your awesome sharing. Could you please share with me the link about the park distance example? I didn't find it

[@jonghak.lee_simulation]

@@yingliu1455 drive.google.com/file/d/1ITP-i93vJIMKGjrs5lz51aaW4kMZYasy/view?usp=drivesdk

[@jonghak.lee_simulation]

@@yingliu1455 drive.google.com/file/d/1ITP-i93vJIMKGjrs5lz51aaW4kMZYasy/view?usp=sharing

[@yingliu1455]

@@jonghak.lee_simulation Many thanks Jonghak!!!! Looking forward to talking with you more about Ansys acoustics !!

[@umanggupta950]

Hey Joanghak, why did you use the radiation boundary object? what's would be the difference if one does not use radiation boundary object? and also Thank you very much for the video it really helped me a lot :) kind Regards Umang

[@jonghak.lee_simulation]

ansyshelp.ansys.com/account/Secured?returnurl=/Views/Secured/corp/v201/en/ans_acous/acous_bc_apply.html%23acous_bc_surfimp ansyshelp.ansys.com/account/Secured?returnurl=/Views/Secured/corp/v201/en/ans_acous/acous_bc_abc.html ansyshelp.ansys.com/account/Secured?returnurl=/Views/Secured/corp/v201/en/ans_acous/acous_artificial.html

[@umanggupta950]

@@jonghak.lee_simulation thanks for the quick reply. unfortunately all of these links takes me to the customer portal registration page.

[@umanggupta950]

@@jonghak.lee_simulation I think due to some maintenance work I couldn't visit the website that day. what I understood, is that these layers are there to absorb the out coming waves so that there is not reflection back. and this reduces the computational domain. After reading I have new issue. One of these link said that for a 3-D acoustic analysis, the absorbing boundary must be a spherical enclosure centered at the origin (x0,y0,z0) with radius ra. i am actually performing modal acoustic analysis to find the natural frequencies of a plate in water/fluid. I followed all your steps from this video defining the acoustic region, structural region, FSI and radiation Boundary. I could run it and got damped frequencies. but I made a cubic enclosure for my plate. not Spherical. as you did in your video. is that right ? *I am a bachelor student. and new to Ansys. so I don't really know much.

[@jonghak.lee_simulation]

@@umanggupta950 Yes, you are right.

[@xuewenzhang2811]

Hi, in 2-way coupling, how can I define impedance for a physical region.Thanks

[@vmdklfvmzkdlfv]

안녕하세요. 교수님. 음향해석 시뮬레이션을 공부중인 학생입니다. Harmonic response 모듈에서 acoustics, piezo and mems 두 가지 ACT를 사용하고자 하는데 piezo and mems는 사용에 문제가 없으나 acoustics ACT가 ANSYS 19.1, 19.2까지만 지원하는걸로 알고있습니다. 따라서, 경계조건이 잘 설정되지 않는 문제가 발생하고 있습니다. 제가 현재 가지고 있는 버전은 ANSYS 2019R1, 2020R1 인데 어떻게하면 저 두 가지 ACT를 사용할 수 있을까요?

[@jonghak.lee_simulation]

kzbin.info/www/bejne/aqaaqKSujKp4pZI 위 링크 참고하세요. ACT 없이 가능합니다. 그리고 저는 교수가 아닙니다. 그냥 평등하게 이름으로 불러주세요.

[@qureshimzi3049]

Hi Lee, you are very good at CFD modeling. I have watched your various tutorials. As Msc work I am interested in investigating the sound transmission capabilities of various materials (sound transmission across various walls of different material). Can you recommend me a tutorial that is very close to my work? Thanks

[@jonghaklee]

Acoustic transmission of laminated materials and composite materials is a very difficult problem. It is possible to construct a model by substituting the transfer matrix based on the experimental results of actual materials.

[@debbyperkasa4454]

Hello, I also have a case for define boundary conditions of acoustics analysis on ANSYS 2019 R3 which I am using. The geometry that I made is a measuring instrument for impedance tube sound absorption referring to the ASTM E1050 standard. Please help me to apply the acoustic analysis system to the impedance tube model, the solution needed is the absorption coefficient. Thanks

[@jonghak.lee_simulation]

Sorry I could not solve your problem.

[@mohamedelfakharany156]

I want too take a course in this advanced level in Ansys can you recommend a source for me ?❣️

[@jonghak.lee_simulation]

Ah... www.youtube.com/@user-nv5tv8lc5w/playlists

[@ianokumu8159]

@Jonghak Lee hi yes i select the accoustic region with no structure body

[@rishirajpadol834]

Hi, how can I select the geometry when it is suppressed already in Mass Source. Thanks

[@jonghak.lee_simulation]

Sorry I could not catch your opinion. How to select the faces of the speaker box cone shape? You can use the Box Select on the Select mode icon. 6:25

[@_LeeJeong_]

ANSYS를 독학 하고 있는 학생입니다. ~ 13:30 까지의 해석을 진행하고자 할 때 This FSI load should be defined on a common interface of acoustic and structural regions. 오류 메세지가 출력되면서 해석을 할 수 없는 경험을 (약 일주일간..) 했습니다. (잘못된 내용이었던것)

[@jonghak.lee_simulation]

공감할 수 없는 오류 현상입니다. 경계조건 설정에 어떤 실수가 있었고 수정되었는지 이력을 알 수 없으므로 원인을 예측하기 어렵습니다. 다만, 구조해석 경계조건에서 변위하중은 음향요소와 구조요소 모두 자유도를 가지고 있으므로 양쪽 모든 Region에서 설정이 가능(APDL 관점에서)할 수 있습니다. 힘 하중은 구조요소에서만 적용되므로 2-way FSI 경계면에 적용할 때는 경계면 절점공유 상태로 인하여 설정이 안 될 수 있습니다. 유한요소의 자유도 관계 때문에 발생하는 오류는 모델에서 객체 선택에 따라 설정 상태(반영? 오류?)가 달라질 수 있으므로 이와 같은 근거에 의한 오류는 이해할 수 있지만, 단순히 경계조건의 이름을 변경하는 것에 기인하는 오류는 Named Selection과 Command object 관계를 제외하고는 경험한 사례가 없습니다. 조금 더 명확하게 오류 원인을 확인해보시기 바랍니다. 오류 원인을 밝혀내는 과정을 거칠 수록 많은 경험이 쌓입니다. 좋은 결과 있으시길 바랍니다.

[@_LeeJeong_]

@@jonghak.lee_simulation 선생님께서 달아주신 답글보고 다시 도전해보았습니다. 동일하게 FSI 오류가 발생하였고 경계조건의 이름으로 오류가 발생했다는것은 저의 착각이 맞았습니다. 알고보니 face가 명확하게 잡히지 않았었던것이 문제였던 것 같습니다. 감사합니다.

[@maneeshvardhanreddyinakoll7765]

So helpful sir, but I am facing problem with giving mass source and fluid solid interface it shows as the either should be "defined on a common interface of acoustic and structural regions", even though I have given enclosure as acoustic region and speaker and slab as physics region. Please give me a solution and if any have faced same issue please help me out

[@jonghak.lee_simulation]

I could not understand your information is not enough. I need more documentation I understand it correctly.

[@maneeshvardhanreddyinakoll7765]

@@jonghak.lee_simulation here in the video you have given the mass source and FSI ,which I am not able to give directly as you have done. If I try to run for solution ,it is showing error as "mass source and fluid solid interface should be defined on a common interface of acoustic and structural regions".

[@jonghak.lee_simulation]

@@maneeshvardhanreddyinakoll7765 Ensure that the boundaries of the acoustic and structural zones are correctly separated in the CAD model. Share the boundary between acoustic and structural areas by node merging. Do not duplicate boundary sharing with contact conditions. Mass source and FSI boundary conditions are applied to the surface of the acoustic domain. Therefore, when setting the boundary conditions, Set the boundary conditions when the structural region is hidden and only the acoustic region geometry is visible.

[@maneeshvardhanreddyinakoll7765]

@@jonghak.lee_simulation Thank you I will give it a try😀

[@sagemckook2674]

How did you get the magnitude value for the mass source ?

[@jonghak.lee_simulation]

That is a meaningless value in the example.

[@raguldeep3558]

Absolute Legend

[@1574855]

Thanks a lot for this!

[@divyangpatel3326]

what computer system you use?

[@jonghak.lee_simulation]

I use the laptop Lonovo X13. Refer the link. www.ansys.com/it-solutions/benchmarks-overview

[@cheesyzombie]

Would it be possible to get a copy of the 'Acoustic_parameters' excel worksheet please?

[@cheesyzombie]

I am referring to the excel spreadsheet shown at about 8 mins. It seems to have a lot of useful calculations

[@cheesyzombie]

@@jonghak.lee_simulation Thanks a lot!

[@josechechi8247]

@@cheesyzombie would you send me, pls ?

[@cheesyzombie]

​@@josechechi8247 www.dropbox.com/s/6y0rouyk0rhqpkd/Acoustic_parameters%20-%20Copy.xlsx?dl=0 P.s. I was trying with Ansys for a project but I found that Comsol seems to have lots more examples online for these kinds of analyses. Will be trying that for the next project.

[@robertcibula8576]

Hello, i have the same version of ANSYS but i cannot transfer data from harmonic response into harmonic Acoustics. Ansys doesnt allow me to do, what can be the problem? Thanks!

[@jonghak.lee_simulation]

Sorry I can not find a reason without any information(solver output data).

[@pranavnair3938]

Hi. I used your method of approach for my experiment on a similar plate. But the total deformation always comes as zero when I solve it. What could I be doing wrong?

[@jonghak.lee_simulation]

In my view, I will check the geometry connection of node merge or contact region.

[@dhruvindarji5795]

Can we use fixed support instead of displacement???

[@jonghak.lee_simulation]

In the APDL command, the Fixed support is "D, ALL NODES, UXUYUZPRES, Value 0" but the Displacement support is "D, ALL NODES, UXUYUZ, Value 0". So if you use the Fixed Support, the selected face has 0 positions and 0 pressure conditions. That is wrong. You have to define 0 positions only. In the multi-physics analysis(Structural+Thermal+Electric+Acoustic...), the Fixed support makes 0 value on all degree of freedom(DOF). Just careful. So I recommend Displacement support.

[@dhruvindarji5795]

@@jonghak.lee_simulation Thank you so much. Could you please make one video on prestressed harmonic acoustic analysis? I am facing problem on morphing mesh. There is no video available on that topic. It would be great help.

[@jonghak.lee_simulation]

@@dhruvindarji5795 You mean the pre-stressed Harmonic is Structure+Modal+Harmonic(using mode superposition method)? In the video, the Harmonic using the Full method has the FSI condition. It can be covered. If you want an initial strain into the harmonic analysis model, you can define the coupling system(Static Structure+Harmonic).

[@dhruvindarji5795]

@@jonghak.lee_simulation yes, but in this video there is only harmonic analysis. I want harmonic analysis with following static analysis (first) in acoustic medium

[@dhruvindarji5795]

@@jonghak.lee_simulation yes but I am facing problem. Is it possible to make one video?

[@taha-Alious]

Hi i dont have speaker box plat

[@jonghak.lee_simulation]

Refer the Acoustics ACT in Ansys App store or have to make it.

[@taha-Alious]

2:18 i cant share why

[@taha-Alious]

Why

[@rohansabu1358]

Can anyone please help me to simulate an acoustic black hole in ansys

[@jonghak.lee_simulation]

Do not use the Fixed support on the acoustic domain. Recommend the Displacement support. Because the Fixed support made the pressure dof to 0 value. So you have to use independent ux uy uz constraints condition as Displacement support.

[@genewu6296]

my solution velocity is zero I don't know why !!!

[@jonghak.lee_simulation]

May, non-FSI condition or no node merge or no contact.

[@ianokumu8159]

Hi Sir, Kindly send me your email ID so i can send you my file and see what is wrong. I cannot apply any acoustic load (as the Mass Source), while the Surface Body is correctly recognized.

[@jonghak.lee_simulation]

Could you select the acoustics region surface without any structure body?

[@onurcatak6920]

@@jonghak.lee_simulation Hi, I have the same problem. I can define mass source for an acoustic region but not structural region as you. Thank you