hello! Tq very much . I have encountered the same error that u got as undefined variable .It would be grateful if you could share how you overcomed it.
This is a different model, but I am currently using comsol to analyze STL due to thin film vibration. I would like to ask you a few questions, is that ok? I'm waiting for your reply.
Hi. is perforated tube is should be selected as interior sound hard boundaries?. because I already selected interior perforated plate for perforated tube boundary setting. thankyou
@@caewitharminhashemi in case of absorptive muffler with perforated tube using COMSOL. do I need to select the tube as interior sound hard boundary? which is the same tube is already set as interior perforated plate for boundary setting in pressure acoustic frequency domain configuration.
@@caewitharminhashemi Hello Sir, I am a engineering graduate. I am currently working on a project which is based on development of muffler for constant speed Diesel engine. I did analysis for 0-2000 Hz frequency range. Now sir the transmission loss is maximum at 1500 Hz and the engine's rpm is also 1500 RPM. So is there a possibility that the design frequency of this muffler is 1500Hz? Or have I done anything wrong. Please let me know sir, I can also send you graphs of transmission loss
Hello, sound transmission loss only depends on the geometry of the muffler, and there aren't any dependencies on the engine. You have to find the firing frequencies of your engine and design your muffler for these specific frequencies.
@@caewitharminhashemi Hello Sir, the EFR is quite low. It's 12.5 Hz so in that case the TL is in 0. Decimals. And when done for first 100Hz, the max achieved TL is 2.4 decibels
Hello, "acpr" means pressure acoustics, frequency domain. "Rho" and "c" are the density of air and speed of sound, respectively. I called speed of sound and density of air from "acpr" physics.
Hello, thank you very much for your reply. I have one more question. When calculating STL, can you directly take 20*log10(abs(Pi/Pout))? Or do we have to use 10 times the logarithm and calculate with power instead of directly integrating pressure?
Hi sir, Your videos are most helpful. I have sent a mail to you regarding my project work in the similar topic. I really need your help to finish the work. I hope you will check the mail.
سلام جناب اقای هاشمی. وقتتون بخیر. بنده این کتاب جامعی که توی کلیپ معرفی کردید در مورد مافلرها بود ، خیلی جستجو کردم ولی نسخه اصلیش رو پیدا نکردم . میخاستم ببینم این نسخه رو میتونید واسه من ارسال کنید . اگر لطف کنید اینکار رو برای بنده بکنید خیلی ممنون میشم ازتون. ادرس ایمیل بنده : hessamzabihi@yahoo.com
![[LIVE] : ONE ลุมพินี 88 | คู่เอก "ป้อมเพชร vs อัสลามจอน"](http://i.ytimg.com/vi/1ZqTVVbMgbo/mqdefault.jpg)
thanks so much. your video was life saving. I had problems in the metamaterial i was dealing with and your tutorial worked well.
Thank you.
hello! Tq very much . I have encountered the same error that u got as undefined variable .It would be grateful if you could share how you overcomed it.
@@-AJatinsai hello
Which error? I don't remember
@@caewitharminhashemi the error which encountered of undefined variable during transmission loss at 13:32
@@-AJatinsai you should update solution after adding variables
@@caewitharminhashemi sir whereas I was able to plot reflection coefficient
با سلام .
از ویدئو خوبتون متشکرم. امیدوارم روند خوبتون رو ادامه بدین. موفق باشین.
قربان شما، لطف دارید.
Thank you so much,i have a question please,why p0 =1
Hello. Sound transmission loss is independent of acoustic pressure. Therefore, whatever number you enter, the result is the same
Your video are totally awesome
This is a different model, but I am currently using comsol to analyze STL due to thin film vibration. I would like to ask you a few questions, is that ok? I'm waiting for your reply.
@@やや-j9u hello. Of course
@@caewitharminhashemi Can you tell me your email if you don't mind so I can send you a picture?
hi can you plz tell me how should i import cfd data (pressure, velocity,temp,etc ) to comsol ?? for the analysis of transmission loss
Hello. Add a cfd physics and linear Navier stokes. Then mapping the cfd mesh to the acoustics mesh
Could u share your files?
I haven't this exact file. But I will upload a similar file.
Hi. is perforated tube is should be selected as interior sound hard boundaries?. because I already selected interior perforated plate for perforated tube boundary setting. thankyou
Hello, sorry I didn't understand. Could you please explain more?
@@caewitharminhashemi in case of absorptive muffler with perforated tube using COMSOL. do I need to select the tube as interior sound hard boundary? which is the same tube is already set as interior perforated plate for boundary setting in pressure acoustic frequency domain configuration.
@@nursaadah3814 yes. If you don't use interior sound hard boundaries. It's like there is no tube in the chamber of muffler.
@@caewitharminhashemi even I have selected interior perforated plate for the tube?
@@nursaadah3814 no, if you selected interior perforated, it's a tube that has perforated on it.
Please can you help me, I followed your steps and did on analysis. I need your little help. Just a little
of course. what's your problem?
@@caewitharminhashemi Hello Sir, I am a engineering graduate. I am currently working on a project which is based on development of muffler for constant speed Diesel engine. I did analysis for 0-2000 Hz frequency range. Now sir the transmission loss is maximum at 1500 Hz and the engine's rpm is also 1500 RPM. So is there a possibility that the design frequency of this muffler is 1500Hz? Or have I done anything wrong. Please let me know sir, I can also send you graphs of transmission loss
Hello, sound transmission loss only depends on the geometry of the muffler, and there aren't any dependencies on the engine. You have to find the firing frequencies of your engine and design your muffler for these specific frequencies.
@@caewitharminhashemi Hello Sir, the EFR is quite low. It's 12.5 Hz so in that case the TL is in 0. Decimals. And when done for first 100Hz, the max achieved TL is 2.4 decibels
@@ritvikpatil4703 its not important. No one can hear noise in 12.5 Hz
Hello, I have a question. What is acpr. rho&acpr.c mean?
Hello, "acpr" means pressure acoustics, frequency domain.
"Rho" and "c" are the density of air and speed of sound, respectively. I called speed of sound and density of air from "acpr" physics.
Hello, thank you very much for your reply. I have one more question. When calculating STL, can you directly take 20*log10(abs(Pi/Pout))? Or do we have to use 10 times the logarithm and calculate with power instead of directly integrating pressure?
hello may i get the copy of the book in the video?
Hello, please send me an email.
Thank you so much
You're welcome
Please let me know
Hello! Can you help me to read book “acoustics of ducts second edition”, may be you can send me copy your book?
Hello, please send me an email. I'll send you this book.
Armin.hashemi.k@gmail.com
@@caewitharminhashemi drobgon@outlook.com
@@caewitharminhashemi you are the best! Thank you!
hi may i get the book?
Hellooooo
Hi sir,
Your videos are most helpful. I have sent a mail to you regarding my project work in the similar topic. I really need your help to finish the work. I hope you will check the mail.
Okay send me your model
@@caewitharminhashemi sir i have it already.. Can you please share your mail id once more
@@jagath7594 armin.hashemi.k@gmail.com
@@caewitharminhashemi i have sent it on 2nd September 2021. I have resent it now again. hope you received.
سلام جناب اقای هاشمی. وقتتون بخیر. بنده این کتاب جامعی که توی کلیپ معرفی کردید در مورد مافلرها بود ، خیلی جستجو کردم ولی نسخه اصلیش رو پیدا نکردم . میخاستم ببینم این نسخه رو میتونید واسه من ارسال کنید . اگر لطف کنید اینکار رو برای بنده بکنید خیلی ممنون میشم ازتون. ادرس ایمیل بنده : hessamzabihi@yahoo.com
سلام، ممنون. برای شما ایمیل کردم