Complex Flow Field Of The Whole Machine N-s Equations Numerical Simulation,

This thesis concentrates on application of CFD. Through the numerical simulation, an aircraft's aerodynamic characteristics has been investigated. The main research issues include: creating a UG model of the plane, structured computational grid generation, solving the N-S equations and analysis of flow field. Numerical solution of 3D NS equations based on multi-block grid techniques was studied with finite volume method. The boundaries between each multi-block grid are point to point patched grids.At the very beginning, the UG model of the aircraft was created according the configuration data, and some simplification was introduced to make the grid generation being more convenient without significant change of the aerodynamic characteristics. Then generate the 1-1 patched multi-grids . Structured multi-grid generation is the main method of complicated flow field. The flow field is divided into many regions, then generate grids in each region, and then solve the governing equations separately. The convective terms are discretized using upwind flux-difference-splitting technique of Roe. An implicit approximate factorization method is used to advance in time. The flow field around the aircraft is acquired through steady computation. The computational results are compared with experimental results, which demonstrates that the patched grid algorithm has good accuracy and practicality in the simulation of complicated flows.Besides the simulation of the characteristics of an aircraft, a quasi two dimensional flow approximation theory was created to simulate the performance of an axial cooling fan.