Numerical Simulation of Complex Geometries
Abstract The numerical simulation of fluid flows and heat transfer over complex geometries, especially for three dimensional problems, remains a challenging problem in computational fluid dynamics. This paper proposes a method to approximate the contour of irregular geometries in Cartesian coordinates. In order to achieve a smooth boundary representation, both diagonal segments and Cartesian grid lines are utilized in the approximation. When the geometric object is specified with a set of discrete points, the approximate representation of the object contour is drawn based on the local monotonic principle such that the essential topographical character of the object is preserved. The accuracy of approximated contour on the Cartesian coordinate is estimated by the convergence of contour length and normal distance between the approximated and original contour. The proposed techniques is illustrated by the contours of complex lake banks, multi-cylinder, porous media and the sphere, which are often encountered in fluid devices and heat exchangers.