Heat exchange in cylindrical pipes with complex cross section under mixed boundary conditions

The method of R-functions and the Laplace transform method are used to calculate heat transfer in cylindrical (prismatic) pipes of complex cross section under mixed boundary conditions for a hydrodynamically stabilized laminar flow of a viscous incompressible fluid in the pipe. It is assumed that the temperature of the inner wall of the pipe is constant and that its outer wall is thermally insulated. Numerical calculations are presented for several specific cases involving pipes of various geometries.