One-Dimensional Turbulence Modeling Methods And Their Applications For Compressible Turbulent Flows

In the basic research and engineering practice of advanced aerospace vehicles in the future,high-precision compressible turbulence numerical simulation methods are needed to provide reference for the design of aircraft.Based on the requirements mentioned above,the One-Dimensional Turbulence(ODT)is selected as the research object in this thesis.Based on the conservative compressible ODT model developed by our group,the accuracy of the model verified by simulating representative turbulence flow in the thesis.Then the model is applied to the study of the characteristics of the compressible wall turbulence,and the improved model is applied to simulate the free shear turbulence.The research work of the thesis is carried out according to the ideas of the theoretical derivation,mathematical modeling,numerical implementation,numerical verification and application of the method.Firstly,the thesis makes a complete exposition of the model theory.After introducing the limitations of the current turbulence numerical simulation methods in simulating high-speed turbulence problems,the necessity of developing ODT model methods is introduced.Subsequently,the modeling ideas and theoretical details of the ODT model method are elaborated.Then,the thesis work enters the stage of mathematical modeling.Basis on the verification of the incompressible ODT model under the Euler frame,our research group improved the model from the mathematical modeling level and developed a conservation type compressible ODT model.This thesis improves the function of the new model for the components,so that the model has the function of simulating multi-component compressible free shear turbulence.After completing the mathematical modeling,it enters the stage of numerical implementation and numerical verification.In this thesis,the conservation type compressible ODT model is verified in detail based on the classical case of supersonic channel turbulence.The results show that the new model can simulate the average flowfield with the accuracy close to DNS,and can capture the basic trend of turbulent fluctuation characteristics in the flowfield.The new model inherits the advantages of traditional ODT method,such as low calculation cost and high accuracy in incompressible wall turbulence simulation.The model is applied initially based on the verification of its accuracy.Our research group has fully verified the simulation accuracy of the conservation type compressible ODT model for the isothermal wall supersonic channel turbulence,and the application of the model in this problem is almost mature.In this thesis,based on the idea of control variables,a series of supersonic channel turbulence cases under multiple operating conditions are setted.The model method is applied to study the variation of the turbulent flowfield characteristics on Reynolds number and Mach number.Resultly,with the increase of Reynolds number and the increase of Mach number,there are contrary effects on average characteristics of the flowfield and fluctuation characteristics of the flowfield near the wall,but both promoting effects on fluctuation characteristics in the mainstream.In addition to the application in wall turbulence,the improved model is also applied to simulate the free shear turbulence.The results show that the model can accurately simulate average flowfield of the spatially developing mixing layer in the self-similar stage,and accurately capture the distribution of turbulent fluctuation intensity in the flowfield.The simulation accuracy is better than the large eddy simulation with the linear eddy model coupled(LES-LEM)and large eddy simulation method with gradient diffusion closure(LES-GRAD-DIFF).