June 22, 2021 at 2:43 pmSaifulSubscriber
I am a new learner of Harmonic Acoustics. Recently I am modelling a project for acoustic propagation in an aquarium of a rectangular shape whose top is opened to the atmospheric air. I have a sound source at exactly the middle of the tank. I can model the source as a monopole acoustic pressure source. The source produces 76 dB (dB re 20 uPa) at air (calibrated). I want to simulate the sound propagation inside the aquarium. My understanding so far is that for the five glass surfaces I can treat them as hard boundary (default in ANSYS as well) since they are smooth and good reflector of sound. Can anyone help me how can I select the boundary condition at the open surface? The open surface is the water/air interface and they have two dissimilar impedances. How can I model such boundaries?
Please help. I am in badly need of support to complete my project.June 22, 2021 at 2:52 pmErik KostsonAnsys EmployeeHi
There is a big specific impedance mismatch between air and water (since it is impedance~rho-c_speedofsound), so the acoustic waves from/in the water will be reflected there at the interface (watre/air) since the reflection coefficient is close to 1, and the same if the waves come from the air into water.
So the water is like a waveguide and the acoustic energy stays inside there .
Now the boundary condition (BC). So i think a zero acoustic pressure (p=0), so sound soft BC, should be OK there at the air/water interface (otherwise we can model the air and the water as acoustic media).
All the best
June 22, 2021 at 3:33 pmSaifulSubscriberHello Erik Thank you for your answer. Yes, there is a huge impedance mismatch. However, can you tell me how can I define a soft boundary at the top? I was thinking to define the top as an impedance boundary with resistance (343*1.21 = 415 Pa.s/m) and zero reactance. or do I need to use the impedance of water (1481*1000 Pa.s/m)?
Any thoughts on it?
June 22, 2021 at 3:53 pmErik KostsonAnsys EmployeeHI just use the pressure BC in Harmonic acoustic and set it to 0 so p=0 at the interface.
Viewing 3 reply threads
Ansys Innovation Space
- You must be logged in to reply to this topic.
Simulation World 2022
Check out more than 70 different sessions now available on demand. Get inspired as you hear from visionary companies, leading researchers and educators from around the globe on a variety of topics from life-saving improvements in healthcare, to bold new realities of space travel. Take a leap of certainty and check out a session today here.
Earth Rescue – An Ansys Online Series
The climate crisis is here. But so is the human ingenuity to fight it. Earth Rescue reveals what visionary companies are doing today to engineer radical new ideas in the fight against climate change. Click here to watch the first episode.
Subscribe to the Ansys Blog to get great new content about the power of simulation delivered right to your email on a weekly basis. With content from Ansys experts, partners and customers you will learn about product development advances, thought leadership and trends and tips to better use Ansys tools. Sign up here.Trending discussions
- How to calculate the residual stress on a coating by Vickers indentation?
- An Unknown error occurred during solution. Check the Solver Output…..
- Saving & sharing of Working project files in .wbpz format
- Solver Pivot Warning in Beam Element Model
- Understanding Force Convergence Solution Output
- Colors and Mesh Display
- whether have the difference between using contact and target bodies
- The solver engine was unable to converge on a solution for the nonlinear problem as constrained.
- Massive amount of memory (RAM) required for solve
- What is the difference between bonded contact region and fixed joint
Top Rated Tags
© 2022 Copyright ANSYS, Inc. All rights reserved.Ansys does not support the usage of unauthorized Ansys software. Please visit www.ansys.com to obtain an official distribution.