The formation and collapse of vapor cavities is a common transient phenomenon that can have a significant effect on the evolution of the pressure in a piping system. BOSfluids has therefore, since its earliest releases, implemented two widely-used cavitation models: the Discrete Vapor Cavity Model (DVCM) and the Discrete Gas Cavity Model (DGCM). While these have proven to be reliable and fairly accurate, they have some well-documented shortcomings.
The upcoming release of BOSfluids, version 7.1, implements a new cavitation model named the Homogeneous Vapor Cavity Model that addresses some of the shortcoming of the DVCM and DGCM. The HVCM assumes that vapor cavities (bubbles) are dispersed homogeneously throughout the liquid, or collected in distinct, larger volumes, or combinations thereof. A continuous liquid fraction describes the size and distribution of the vapor cavities. The DVCM and DGCM, on the other hand, assume that vapor or gas-filled cavities exist only at the flow grid points, and that the cross-sectional area of a cavity equals the cross-sectional area of the pipe.
In contrast to the DGCM, the new HVCM does not require any additional input parameters and produces results that are in better agreement with experiments than the results produced with the DVCM. The HVCM is also less sensitive to the resolution of the flow grid than the DVCM. This means that if there is no reason to assume that the amount of entrained gas (air) is significant, then the HVCM is a better choice than the DVCM. The latter remains available for backward compatibility though
While BOSfluids was already an excellent tool for the analysis of transient flow phenomena in piping system, the new cavitation model makes BOSfluids an even more compelling choice for your next engineering project.
Furthermore, we would also like to inform new and future users that our “Water hammer/surge analysis using BOSfluids” training course is available as an online training course. For more information on this course and other courses please visit us on EngineeringTrainer.com.
For more information on BOSfluids licenses and pricing, please contact:
+31 85 058 00 46
or request the demo version.