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@@TheyCallMeApplePie hello, thank you for your suggestion. I will record it in my spare time

@@aminghasemzadeh5462 سلام خواهش میکنم. اگر وقت آزاد شد حتما.

@@caewitharminhashemi بسیار عالی موضوع پایان نامه بنده طراحی یک مبدل تانپیلز هست من مبدل رو با مدار معادل شرمن باتلر بهینه سازی کردم که بیشترین پهنای باند رو داشته باشه بعد مبدل بهینه شده رو با روش مدار معادل میسون مدلسازی کردم الان باید مبدل رو تو کامسول شبیه‌سازی کنم اگر ممکنه می‌خواستم از شما راهنمایی و کمک بگیرم تشکر

@@aminghasemzadeh5462 من زیاد آشنایی با کار شما ندارم. ولی ایمیل و تلگرام من توی سایت هست. میتونید پیام بدید

@@zahraelyasvand6056 thank you

@@muhammadnisarqasim636 Hello, unfortunately, I don't know. My expertise is in mechanics, so it would be better to consult someone with a background in electronics.

Hello. The absorption coefficient in the JCA model depends on five parameters. If you adjust any of these parameters, the results will change accordingly.

@@caewitharminhashemi Thanks for the reply and this video. I was searching for a tutorial in internet. This video helped me to learn numerical simulation.

@@SumandeepSinghRana you're welcome.

@@the24thintrovert okay. Thank you for your suggestion

There is a circle with a diameter of 2 meters, which is far from the center of the propeller.

@@k.m3129 of course, I will record a video about it in the future

@@abderrahimbarhoumi9003 you're welcome. I haven't any experience in nanotubes. If your model is prepare and has some issues, email it to me and I'll check it

Hello. I haven't calculated before. You should look up in books.

@@caewitharminhashemi Yes sir analytically i can do. Thanks for your guidance.

Hallo. Thank you for your suggestion. These models are very time-consuming and have few viewers because they are specialized.

@@caewitharminhashemi Thank you very much for your attention! <3

Hello. Check yplus it must be below 2. What is your fluid model?

Hello. I did understand. What do you mean source is outside the domain?

@@chris57926 you're welcome

@@juanmanuelorlandomelidoni9110 I think you forgot to enter pressure amplitude in the inlet port

@@caewitharminhashemi No its defined as 1Pa

@@juanmanuelorlandomelidoni9110 unfortunately I have no idea

Of course. I have a video but it needs edit. I'll upload it ASAP

All boundaries are rigid by default in acoustics system. No need to define rigid boundaries

Another question sir. Is it possible if i apply surface velocity and radiation boundary at the inlet face? Or we can ignore it?

@@nurulsyafina1086 absorption coefficient is independent of inlet. Port boundary is defined to calculate absorption coefficient and no need to other boundaries

Hello. Please email me some photos of path lines. Armin.hashemi.k@gmail.com

Hello. add a interior perforated plate boundary on the poroacoustics domain. it's not complicated.

@@caewitharminhashemi ok sir i will try. Will you pls share your email ?

@@caewitharminhashemi sir so is it possible to implement in 3 D. as well also do I have to use MAA's equation for that.. only this boundary condition is sufficient?

@@PriyankaSuryawanshi-if7du I suggest that you solve model with the perforated boundary condition first. 3D model is another scenario and needs another physics in comsol. The Maa equation is not available in Comsol

sir do we have to model this as 2D?

It is a 3D crystal modeled in 2D and depth is not taken into account. You need to model the perforated plate in 3D.

Thank you. of course

Hello. It is installed like the previous versions. What is the problem with the installation?

Install but software was no open

Yes previous version 6.1 are open but this version are not be work sir

Maybe the software has a problem.

Mat be sir

سلام. مشخص نیست هنوز.

Sorry I don't understand what you mean.

Hello. how can i help you

@@caewitharminhashemi Hi Armin. Thanks for answering. I would like you to help me put in COMSOL (in the variables part) the impedance that appears in the article I mentioned. I didn't want to bother you, you taught me a lot but I have doubts about how to put this variable that appears in the article in COMSOL.

@@gabrielhernandezrozo848 please email me article.

@@caewitharminhashemi I sent you the article by email.

It happens sometimes. Because mesh motion is used. In the steps interval that diverges, increase the residual value. After passing that interval, return it to the first values.

@@caewitharminhashemi Thank you for your reply. When I met this situation for the first time, your way can solve the problem effectively. But when I ran into the problem the second time after 60 more steps, I tried to raise the residuals to 0.1,10,100, 10,000, but still couldn't diverge after calculating up to 12 steps. And the residual value is getting larger and larger.🥺

@@JjownO check mesh and time step. problem is due to one of these

Hello. If the propeller tip Mach is low. No need to define a surface (permeable FWH) because the quadrupole sound source is weak. You have to define surface in jet noise calculation because quadropole source is dominant

@@caewitharminhashemi Thanks a lot for your explanation.

Armin.hashemi.k@gmail.com

@@caewitharminhashemiI also have some questions, may I ask you for advice？Thank you for your reply.

@@user-kx1jm4zx8k hello. of course

@@caewitharminhashemi It‘s so great,thank you.

Hello. I will record it in the future

It's not my speciality. Maybe one day i made it

@@caewitharminhashemi ok thanks anyway

Do you achieve that?

I think you should clean up your geometry.

@@caewitharminhashemi do you mean to use the command fill in spaceclaim?

@@omerabdo8674check extra edges, holes, inexact edges, etc

@@caewitharminhashemi btw I am using the same geometry you gave in the discription

@@omerabdo8674 i have no idea.

Inlet and outlet are pressure outlet. You can add a inlet velocity if the propeller moves in air.

No. You cannot use symmetry or periodic boundary condition in mesh motion. It uses in stationary solution.

@caewitharminhashemi thank you🙂‍↕️ So I can't simulate the noise of one blade.🥲 All of it has to be.

Hello. You can use it in 3D space. There is no particular difference.

R is reflection coefficient. Pressure reflected to pressure incident. Here I used power, not pressure (p). Therefore alpha =1-R. Power is proportional to p^2.

Well noted. Thanks. I have one more question. If we calculate the reflection coefficient (R) from surface impedance (Zs), is it possible to realize it in Comsol?

@@BondanDwisetyo yes. There are several examples in Comsol library

You're welcome

You're welcome

Hello. Sound transmission loss is independent of acoustic pressure. Therefore, whatever number you enter, the result is the same

Hello. Thank you for your comment. Okay

Hello. Arc length is 0.1 meters in x axis. This is length of cut line

@@caewitharminhashemi Thankyou Sire. Could mind to give us a tutorial for measure droplet diameter by cut line plot in COMSOL? Especially in microfluidics

Hello. Create three layers. Two layers for aluminum sheets and one layer for poroacoustics material.

Ok I will try.​@@caewitharminhashemi

Thank you

Did you use body of influence?

Yes!

@@JjownO You cannot use both. Remove boi to access buffer layers

@@caewitharminhashemi thank you!

سلام، خواهش میکنم. ساده‌ترین را اینه که یک پراب از قسمت definitions اضافه کنید و برای آن SPL را تعریف کنید. مکانش هم می‌تونید تغییر بدید.

دستتون درد نکنه، چجوری منبعی که صدا تولید میکنه را قدرتش را بر حسب spl بدم؟ خودتون تو آموزش بر حسب power وارد کردید @@caewitharminhashemi

@@MohammadHoseinAhmadi-io6yy تا جایی که یادمه برحسب فشار دادم و سه در سه جهته. فشار را باید بر حسب پاسکال وارد کنید. اگر بر حسب دسی‌بل دارید باید آن را تبدیل به پاسکال کنید

Thank you. I'm only a simple engineer. I downloaded this propeller from grabcad website. I don't remember exact name of model. As I know it's DJI propeller.

Thank you 🌹

Thank you

Hello. Thank you very much 🌹

ممنون از شما. الکتریک را باید یکی بگه که رشتش باشه. من مکانیک خواندم و همین همین مباحث را آشنایی دارم.

Yes.

I haven't seen frensel number in results. Maybe you should define it. Yes you can calculate insertion loss.