NUMERICAL SIMULATION OF INCOMPRESSIBLE LAMINAR ENTRY FLOWS IN A SQUARE DUCT OF $90^{\circ}$ BEND BY UNSTRUCTURED CELL-CENTERED METHOD

비정렬 셀 중심 방법에 의한 정사각형 단면을 갖는 $90^{\circ}$ 곡관 층류유동의 수치해석

Three-dimensional steady incompressible laminar entry flows in a square duct of $90^{\circ}$ bend are numerically simulated by a new solution code(PowerCFD) using unstructured cell-centered method. Solutions are obtained with three unstructured grid types of hexahedron, prism and hybrid at a Reynolds number, based on the hydraulic diameter and bulk velocity, of 790. Interesting features of the flow are presented in detail. Detailed comparisons between the computed solutions and the available experimental data are given mainly for the velocity distributions at cross-sections in a $90^{\circ}$ bend of a square duct with fully-developed entry flows. It is found that the code is capable of producing the nature of laminar flow in curved square duct with no grid type dependency.