General Mechanical

General Mechanical

Difference between pressure in structural and acoustic analysis

    • Samir Kadam
      Ansys Employee
      What is the difference between pressure in structural and acoustic analysis?n
    • peteroznewman
      Subscriber
      When solid elements mesh a volume, the nodes are assigned different unknowns for the two types of analysis.nStructural models have displacement of the node in X, Y and Z as the unknowns. Pressure can be applied to the node to make it move to a new static or dynamic equilibrium position, or to have an amplitude and frequency of oscillation in a harmonic response analysis.nAcoustic models have pressure at the node as the unknown. Pressure can be applied to the nodes in the form of an acoustic excitation, but the nodal XYZ coordinate doesn't move, the pressure wave can move through the mesh.n
    • Ashish Khemka
      Ansys Employee
      Hi,nnWe can specify a Pressure load in a structural analysis, which is an excitation (force/area). On the other hand, in an acoustic analysis, pressure is a DOF constraint (boundary condition, not excitation), where the total pressure (e.g., incident + reflected) is being specified. The two are not interchangeable, as they have different usage in structural vs. acoustic analyses - in the former, pressure is a load/excitation whereas, in the latter, pressure is a DOF that we solve.nnRegards,nAshish Khemkan
    • peteroznewman
      Subscriber
      Array Let me clarify what I meant by Pressure can be applied to the nodes in the form of an acoustic excitation. The Acoustics training material provides this equation to convert a surface velocity excitation into incident pressure:n
      Add Tags