[Denied]

Hello,i am new in CFD and i want to simulate a von karman vortex shedding over a cylinder in 2d.I do not understand why it was said to use a pressure based solver and not a density based one. I am working with a Re=100.
If someone can help me understand the reason behind this choice i would really appreciate it .

[truffaldino]

Originally Posted by Denied

Hello,i am new in CFD and i want to simulate a von karman vortex shedding over a cylinder in 2d.I do not understand why it was said to use a pressure based solver and not a density based one. I am working with a Re=100.
If someone can help me understand the reason behind this choice i would really appreciate it .

Because you are working with very slow incompressible flow.

The pressure-based approach was developed for low-speed incompressible flows, while the density-based approach was mainly used for high-speed compressible flows.

In the pressure-based approach, the pressure field is extracted by solving a pressure or pressure correction equation which is obtained by manipulating continuity and momentum equations

In the density-based approach, the continuity equation is used to obtain the density field while the pressure field is determined from the equation of state, i.e you should add equations that relate pressure to density and temperature, which are,in turn, extracted from isoentropic conditions etc. Besides adding complexity in the case of incompressible liquid, this only works well for close to ideal gases, not dense liquids.