Around The Bus Body Numerical Simulation Of The Spatial Discretization

The discretization of the space around bus body is one of the key steps in the studying of numerical simulation to the flow field surrounding bus. By analyzing the mathematical description of curves and surfaces, the methods of mesh generation and the questions we face at present, the space discretization that will be used in finite element numerical simulation is particularly carried out based on the surface numerical modeling of the bus body. The surface numerical modeling of bus body is the base of the space discretization. As the bus body composes of mass free surfaces, B-Spline and NURBS are applied. According to the reverse engineering principle, and on the basis of the datum that comes from three-dimension measure experimentation, the modeling of buses body is established. Also, the method that the surfaces commonality connecting are joined and the triangle field is sewed by applying the double cube B-Spline style is utilized. The three-dimension space around the bus has been partitioned topologically according to topological theory so as to improve the quality of mesh and elements generation from the division of the space. In this work, the datum which are provided by the above modeling have been used, the method that composes of algebra equation and ellipse equation has been adopted leading to measure off the three-dimension space surrounding the bus. Exponent function control method is presented to further advance the quality of the mesh and elements. For speeding up the discrete rapidity, the elliptic equation improved by parabola has been applied. The means that known as the least node amount section advance is educed to optimize node number order. With Visual programming language, 3D-BusMesh software has been developed in Windows environment. On the basis of numerical modeling of the bus body, the automatic topological partition of the space enclosing the bus body and the elements discretization have been accomplished automatically resulting in node-coordinate and element-node information.