Set Up Compressible Flow Modeling
Simulate high speed flows with speeds ranging from subsonic to transonic up through low supersonic conditions. Compressible flow simulations should be conducted using a transient analysis with ideal gas properties for air. AcuSolve will compute the coupled system of compressible NS equations with a single non-linear iteration using the "compressible_flow" stagger. Compressible flow is compatible with the supported turbulence models and most other existing AcuSolve features
- General usage
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- Analysis must be transient.
- Heat transfer should be on with or without turbulence active.
- Inflow boundary conditions
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- Stagnation pressure inlet and static pressure outflow are the preferred boundary condition specifications.
- Subsonic conditions require two variables as input while supersonic conditions require three.
- Mach number is computed by and positivity of both pressure and temperature are checked by AcuPrep.
- When the specified inflow condition is subsonic, pressure is ignored, and only velocity or Mach number and temperature are used as the boundary conditions.
- Outflow boundary conditions
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- Subsonic: The user-specified pressure is fixed.
- Supersonic: The user-specified pressure is ignored if it is lower than the computed pressure on the outflow surface.
- Nodal initial conditions
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- It is important (critical in most cases) to specify valid initial values for all the solution quantities. Pressure and temperature must be defined such that density is realistic.