I written c-code for rotoray componet of wankel engine, which dynamically links the fluent solver, which enhance the standard features of the solver. i have done unstructured grid for the housining. after, not even 1 sec the solver shows the negative volume detected...? what exactly it mean ? how to minimize the negative voulme.? please can anybody help in this regard.

Somasekhar.m

may be your mesh very fine so the first point of your grid is smaller than your geometry tolerance so fluent see this volume with negative value. so you need to rebuild your grid with a smother geometry or with courser mesh