| The outer flow field over high-speed train is complex turbulent noW whichcause some unfavorable innuences to thc train and to the surmundings. so it isattended and studied by researchers of the vehicle aerodynamics all the time.Considering the characters of the viscoidal turbulent flow over high-speed train,the computing model of the outer fiow field for high-speed train has beenestablished based on the incompressible fluid Navier-StOkes epuation and theturbulent model of ke two equations. The equation set of the flow field problemvia finite element methods (FEM) has been set up. To assure astringency, sometechnologies have been used such as iterative penality function methods,assemblage mass matrix, reduced integration algoritlun, NeWton iteration methodwith parameters for non-linear equation set, introducing relax factors and doublesteps solution and so on, and an algorithIn for solving the nonlinear equation set offlow field by FEM has been presented. Aiming at the problem that solution FEMequation set needs too much memory, segregated solotion methOd has beenadopted and for the first in China E l em ent- B y- E lement(E B E ) has been introduc edwhen solving flow field parameter equation sets. EBE technology need notassemble and store the global stiffness matrix, and minish effectively memoryrequires of solution equation set, moreover it has inherent high parallelity, andadvance equation solution. For the first time in China the EBE-PCG andEBE-BiCTSTAB algorithIn have been got by combining EBE technology withPCG and BiCGSTAB, and precondition matrix on the basis of EBE has beenattained. Making use of the computing model and technique above described,these PEM parallel computer prograrns fOr calculation of 2D and 3D turbulentflow have been coded by EBE-PCG and EBE-BiCGSTAB. 2D uPend-step flowand 3D outer flow over high-speed trains of four types of mode train have beencalculated by shuguang 2000 parallel comPuter in nation high capability computecenter (chengdu). Through comparing the calculation results by program with theexperiment results, it is proved that the algorithIns presented in this thesis arecorrect and practicable. In the thesis a new count expression of mesh fractaldimension is introduced, on the basis of it the storage and operation counts of directs solution methods, assembly global stiffness iterative methods and EBE iterative methods have been analyzed and compared, a conclusion has been obtained that the storage and operation counts of direct solution methods is the most, the storage counts of the EBE iterative methods is the least. Estimating compute scale for EBE iterative methods at shuguang 2000 parallel computer, it is make out that compute scale is large in the extreme if make the most of the memory of every processor .By analyzing the parallel compute performance of 2D upend-step flow calculation, it is proved that EBE iterative methods can achieve upper speedup rations. So it is also proved that the parallel compute method based on EBE is effective.The 3D turbulent flow fields around high-speed trains of four kinds of model uain have been calculated by 3D parallel compute program coded with the algorithms presented in this thesis. From the calculation results, the aerodynamic drag of different types of model trains are obtained, some characteristics of the flow field over the high-speed train are analyzed preliminarily such as pressure distribution and diversification, velocity distribution and diversification, and the affections of different train head shape to pressure .velocity, pressure gradient and the like. Accordingly the whole understanding to the pressure and velocity state of flow field around high-speed train is comprehended. For the strength and stiffness design of the train body, resistance wind design of the facilities around high-speed railways and working standard of safe and action for acting people surrounding the train, a reliable criterion for the construction of high-speed...
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