NUMERICAL-ANALYSIS OF CONVECTIVE HEAT-TRANSFER IN THE ENTRANCE REGION OF CUSPED DUCTS

This study presents the numerical solution of convective heat transfer in the thermal entrance region of cusped ducts. These ducts are formed contiguously by assembling three, four, or five cylindrical rods having the same diameter next to each other. The ducts are also subjected to a constant wall temperature. The solution to the discretization of these duct geometries is obtained by using the numerically generated boundary fitted coordinate system. According to this method, the complex domain in the physical plane is transformed into a regular square domain in the computational plane. The finite difference method based on the control volume is then used to discretize the transformed governing equation. To prove the validity of the results, the present method is also used to obtain the convective heat transfer solution in the entrance region of square and equilateral triangular ducts. Comparison of the results for square and equilateral triangular ducts with available data published in the open literature gives excellent agreement. The representative curves illustrating variations of the bulk temperature and Nusselt numbers with pertinent parameters are plotted for the three different duct geometries.