Pumps and compressors are commonplace. An estimate of the pumping requirement can be calculated based on the height difference between source and destination and head loss estimates for the pipe and any obstructions/joints along the way. Investigating the detailed flow pattern around a valve or joint however, can lead to a better understanding of why these losses occur. Improvements in valve/joint design can be simulated using CFD, and implemented to reduce pumping requirements and cost.

butterfly valve

Flow Configuration through a Butterfly Valve

Flows can contain particulates that affect the flow and cause erosion to pipe and valve components. You can use the particle-tracking capability of CFX to simulate these effects.

In this example, water flows at 5 m/s through a 20 mm radius pipe that has a rough internal surface. The velocity profile is assumed to be fully developed at the pipe inlet. The flow, which is controlled by a butterfly valve set at an angle of 55° to the vertical axis, contains sand particles ranging in size from 50 to 500 microns. The equivalent sand grain roughness is 0.2 mm.

The reference temperature is 300 K; the reference pressure is 1 atm.

A mesh is provided. Sand particles and a domain that contains water need to be created; for one part of the simulation the water and sand will be fully coupled, and for the other part of the simulation they will be one-way coupled. To increase the accuracy of the simulation, the inlet will be given a velocity profile that simulates a fully-developed boundary layer.

To solve the simulation, two sets of identical particles are required. The first set will be fully coupled to predict the effect of the particles on the continuous phase flow field and allow the particles to influence the flow field. The second set will be one-way coupled but will contain a much higher number of particles to provide a more accurate calculation of the particle volume fraction and local forces on walls, but without affecting the flow field.

Video 1: Video Animation of Particle Tracks in Butterfly Valve