11.2.1. Setup for Simulations of Liquid Pumps and Turbines

Heat transfer is not significant in most cases, so the heat transfer option can be set to None in CFX-Pre.

The and Shear Stress Transport models are appropriate choices for modeling turbulence. When using the Shear Stress Transport model, ensure a resolution of the boundary layer of more than 10 points. For details, see The k-epsilon Model in the CFX-Solver Modeling Guide.

When setting boundary conditions, a total pressure specified inlet and a mass flow outlet are a recommended practice. The total pressure inlet condition is often more appropriate than the uniform velocity or mass flow inlet condition for cases that assume that the machine is drawing fluid directly from a static reservoir.

As with gas compressors, a good estimate of the timestep is within the region to , where is the angular velocity of the rotating domain in radians per second. Selecting an automatic timestep will result in a timestep of .

The high-resolution advection scheme is recommended.

This document deals with obtaining solutions for cases without cavitation, but cavitation may be present. For advice on how to deal with cavitation, see CFX Best Practices Guide for Cavitation.