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.
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.
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
