Fluid Flow and Heat Transfer in a Two-dimensional Miter-bend : Study of Unsteady Motion by Numerical Calculations : Heat Transfer, Combustion, Power, Thermophysical Properties

Abstract

Fluid flow and heat transfer in a two-dimensional miter-bend were examined in connection with a corrugated wall channel as a means of augmenting a forced-convective heat transfer with a single-phase flow in a heat exchanger. In a previous paper, experimental results were not in perfect agreement with those of theoretical analysis because of the effect of unsteady motion due to the instability of the flow downstream of the bending corner. In the present paper, unsteady motion for Reynolds numbers Re=600, 1000 and 2000 and Prandtl number Pr=0.71 is studied numerically by the finite difference method. The previous experimental results are simulated in outline by numerical calculations, but they do not agree quantitatively with those of numerical calculations for the Strouhal number of fluctuations and the Nusselt number at the concave-side of the wall.