## General Mechanical

Topics relate to Mechanical Enterprise, Motion, Additive Print and more

#### what analysis system that i need to use to obtain a sound pressure of moving wheel along the rail?

• zulkarnainzakri
Subscriber
• Dave Looman
Ansys Employee
To solve a rolling object it's necessary to limit the step size so the wheel doesn't rotate more that one or two degrees per step. nSound is a wave phenomenon so an acoustic analysis is usually harmonic or in rare cases transient. nIt's not obvious that a slow rolling wheel would create very much sound, but hypothetically the systems required are a transient structural analysis (transient so that the surface has a velocity to create waves) followed by a transient acoustic analysis. Workbench doesn't currently support transient acoustic analysis so a transient acoustic analysis would need to be done with APDL commands. nTo scope out the potential difficulties of the proposed analysis it is recommended to do a harmonic-acoustic analysis on a small plate model. This analysis type is supported in Workbench. The air elements for the acoustic domain should be no more than around the wavelength of interest divided by 10. So for example, if you are interested in audible sound of 5000 hz in air, the wavelength would be (343 m/sec)/5000 hz = .07 meters and the element size should be no larger than .07/10 = .007 m or 7 mm. This element size will limit how large the air domain is.n
• zulkarnainzakri
Subscriber
so i just need to analyse directly using the harmonic acoustic analysis ??? or there should be a primary analysis setting followed by the harmonic acoustic analysis....for example transient structural-harmonic acoustic analysis ???n