Numerical investigation of the effect of resistance configuration in the flow channel on heat transfer

In this study, the effect of placing rectangular obstacles in a square section channel on heat transfer was investigated numerically. Channel length was determined as 200 mm. The rectangular obstacles are arranged as shapes of triangular, concave and flat with respect to the channel side surface. Besides, the obstacles were placed on the heating surface 3, 6 and 9 rows and analyzed for the maximum high values of the resistors 20, 40 and 60 mm. The obstacles are selected as 3 mm thickness. The flow is considered in the hydrodynamically fully developed, thermally developing region. The boundary condition of constant heat flux was applied to the lower surface of the test section and the other surfaces were considered as adiabatic. Air (Pr=0,7) was used as a working fluid. In the turbulent flow regime, numerical analyses were performed for the range 10 000-30 000 of the Reynolds number. For numerical analyses, the k-w SST turbulence model was used in ANSYS-FLUENT 14.5 commercial program. In the arrangement of the obstacles, it was seen that the flat obstacles provide maximum heat transfer. However, maximum pressure loss was also obtained in the same obstacle applications.