Developing turbulent heat transfer in a 360°bend of square cross section

This paper reports the computational results on the developing turbulent heat transfer in a 360° bend of square cross section. The centrifugal force acting on the fluid in a bend flow induces strong cross-stream motion. It was found from the computations that the counterrotating vortex pair caused by the centrifugal force are broken into a multicell pattern after the θ = 90° station of the bend and the continuous arising and ceasing of the vortices directly affects the variation of heat transfer through the walls of the bend. Particular attention was paid to the developing process of the vortices because they exert the most significant effects on the convective heat transfer through the bend walls. A low Reynolds number second moment turbulence closure was employed to simulate the near wall turbulence behaviors of the bend.