Zero Gradient Boundary Condition

- June 11, 2020 at 12:49 am
  
  OceanZhou
  Subscriber
  
  Is there a way to impose a zero-gradient boundary condition at the outlet for compressible flow? Such a condition is in OpenFOAM and I'm trying to replicate an OpenFOAM simulation in ANSYS Fluent and am having severe trouble with this.
  
  Furthermore, the OpenFOAM simulation I seek to transfer over has boundary conditions for velocity and pressure at the inlet. Is this possible to do in ANSYS Fluent?
- June 11, 2020 at 3:39 am
  
  Kalyan Goparaju
  Ansys Employee
  
  Hello,
  
  The outflow boundary condition is a zero gradient bc available for incompressible flows in Fluent. For compressible flows, you can try the pressure far-field boundary condition. Please look at the link below.
  
  https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v201/en/flu_ug/flu_ug_sec_bc_pfar.html?q=pressure%20far-field
  
  At the inlet, you can use a mass flow inlet, where you define the velocity (in terms of mass flux) and the static pressure. You can also use a pressure inlet, where you define the total and the static gauge pressure in such a way that the velocity at the inlet is what you are looking for.
  
  Thanks,
  
  Kalyan