Multiphase cavitation is triggered by Multiphase cavitation check box in the TCFD menu, see figure . It is only available for transient calculations. Upon checking, user will be offered additional options, see figure . Unless user is familiar with Schnerr-Sauer model , we recommend using the default values. For more information on Scherr-Sauer model , see citeCavitationScherr. As opposed to previous case, Multiphase cavitation uses different solver, so results may (and probably will) slightly differ, when its triggered on. In this case, only Reference pressure is important, setting is the same as in previous case.
It is not recommend to use both Multiphase cavitation and Cavitation risk at the same time. Cavitation risk is not suitable for solver used in Multiphase cavitation mode, so its results may not be reliable. However, since Cavitation risk is post-processing, other results than its own will not be affected.
Results are delivered in the form of fields alpha.water and alpha.vapor , that contain volumetric fraction of water and vapor respectively. Also, volume of all vapor is evaluated and shown in report, see example on figure . Beware, it shows only volume of vapor itself, not volume of all cells containing some vapor, so it is not directly comparable with volume of all cells with risk of cavitation inception from previous section.
Figure: When Multiphase cavitation is switched on, menu offers additional choices for coefficients used in Scherr-Sauer model