Abstract: In the paper the finite control volume integral formulation are derived in three dimensional nonorthogonal coordinates. The curved coordinate velocities on the control volume surface are taken as conveying ones and the Cartesian coordinate velocities at the center of the control volume as the variables of momentum equation. As an example, natural convection are calculated in two and three dimensional domains of eccentric cylinders and spheres.

Key words: numerical analysis, body fitted nonorthogonal coordinates, finite control volume, convection and diffusion, natural convection, eccentric sphere