Numerical Study Of Chemical Nonequilibrium Flow

The reactive flow is a common phenomenon in the Aeronautics and Astronautics fields.Numerical simulation of the combustion flow is also a hotspot and difficulty in the field of computational fluid dynamics.Due to the introduction of the chemical reaction source term,the governing equations of chemical nonequilibrium flow is extremely stiff and hard to get an accurate numerical solution.It is necessary to seek a fast and efficient numerical method to improve the computational efficiency of solving partial differential equation of chemical non-equilibrium flow.Based on Liu's uncoupling algorithm,this paper divides the governing equations of chemical non-equilibrium flow into twos: flow and chemical reaction.This paper mainly studies the solution of the chemical reaction part.The precise time-integration method is applied for solving the chemical kinetic equations for the first time.This paper proposes two kinds of coefficient matrix,an optimization method of precise time-integration method with a prediction-correction step and studies the influence of weighting parameter on the robustness and accuracy of precise time-integration method.Using the Fortran computer language,a program based on precise time-integration method for solving chemical kinetic equations is written which is used to simulate zero-dimensional combustion with six chemical reaction mechanisms.Comparing the simulation result of the precise time-integration method with VODE and the quasi-steady-state method ?-QSS,the performance of the three methods under different reaction mechanisms and different initial conditions is analyzed.The results of the precise time-integration method are greatly in accordance with the traditional method which means that the precise time-integration method can be used to solve the chemical reaction part of chemical non-equilibrium flow and to some extent improve the computational efficiency.