Is there any way at all to use NDSolve to solve PDE's with more than 2 independant variables. This is actually very important, because if the answer is no, then it makes impossible the use of Mathematica in a huge field: Fluid Dynamics, in which we'd like to numerically model the evolution in time of the velocity or vorticity field. Depending on whether there are 2 or 3-D, this could involve 3 or four indep variables. Is there ANY package or version of Mathematica that allows this to be done? None of the NDSolve examples in Help have more than 2 variables (x,t). I have version 3.0. When I try to NDSolve with limits on 3 variables, it complains that it was expecting Options at position four in NDSolve, not another variable.