Setting Fluid Sources or Sinks

It is sometimes desirable to inject or extract fluid mass directly in simulations without having to define a geometrical representation of the real aperture that is used to do so. For example, the length scale of the actual geometry of the aperture may be too small to resolve adequately. Therefore, injecting the fluid from a much smaller region is an appropriate method.

In Simcenter STAR-CCM+, various region sources are provided to make this kind of approach possible. Cell sets can be used to define the cells to which the region source applies.

The general rule to follow in applying this method is that every transport equation active in the region should have a corresponding source or sink term of the form

$S_{\varphi }=\dot{\mathrm{m\prime \prime \prime }}\varphi$

where $\dot{\mathrm{m\prime \prime \prime }}$ is the mass flow rate of the injected/extracted fluid per unit volume, and $\varphi$ is the corresponding transported quantity. For the continuity equation, $\varphi =1$ .

For each transport equation, the appropriate region condition, and the number of corresponding value nodes that may be added, are given as follows:

• Continuity: Mass Source Option (providing up to four additional value nodes)
• Momentum: Momentum Source Option (providing up to four additional value nodes)
• Energy: Energy Source Option (providing up to four additional value nodes)
• Turbulence: Turbulence Source Option (providing up to two additional value nodes)
• Species: Species Source Option (providing two additional value nodes)