> Does it make really that difference for the calculation time when youre not looking for performance? I once implemented a calculation for the turublent heatflux and there where no big difference in the calculation time. And I used a Mesh with more then 20 Millionen not just a case thats too small to recognize. @User I am always looking for performance in FOAM, I don't say the way proposed by @User is incorrect, it's just slow. Besides we don't know what kind of computer he/she has