The virtual mass force is proportional to relative phasic acceleration. The Ansys CFX implementation is applicable to the particle model only. For details, see Virtual Mass Force in the CFX-Solver Theory Guide. You may specify a non-dimensional virtual mass coefficient . =0.5 for inviscid flow around an isolated sphere. In general, depends on shape and particle concentration. At the time of this writing, there were no universally accepted models. Such models may be implemented using CEL for .

The virtual mass force is proportional to the continuous phase density, hence, is most significant when the dispersed phase density is less than the continuous phase density. Also, by its nature, it is only significant in the presence of large accelerations, for example, in transient flows, and in flows through narrow restrictions.