كليدواژه :
Heat convection , Nusselt number , non-Newtonian fluid , heat exchangers , power-law
چكيده لاتين :
In many kinds of heat exchangers it is used tubes with circular cross section shape, but in this research, a cam shaped
cross section tube as one of them in the instrument has been considered. Forced convection heat transfer to power-law
fluids from a heated cam shaped tube (assumed as cylinder here) in the steady flow has been investigated numerically
by solving the momentum and thermal energy equations using finite volume method and the coupled scheme on a
structure grid. Reynolds number is Re 5, 10, 20, 30, 40 and power law index is n 0.8, 1, 1.2 at a constant Prandtl
number of 1 . The governing field equations have been solved by using a second-order accurate finite volume method to
determine the drag coefficient, flow patterns and to investigate their dependence on power law index and Reynolds
number. In cylinder (Fig. 1.) is 50,60,70,80,91,100 and Tangential. Results show that Nusselt number and heat
transfer of cam shaped cylinder with 91 is greater than other cam shaped cylinder and circular cylinder. The global
characteristics such as drag coefficients and average Nusselt number are calculated and the representative streamline
contours are presented for the above range of conditions. It has been found that the average Nusselt number increases
with Reynolds number for all n considered here and cam shape cylinder with 91 has the highest heat transfer rate.