Axisymmetric Far Turbulent Wake of High-Speed Moving Objects

There are a number of problems of atmospheric entry during descent of high-speed objects (HSOs) from orbit: small entry angle (insufficient deceleration), high drag (high entry speed into dense layers), high overloads (steep descent), and high entry speed (small angle and high speed). The results of the study are used to determine the parameters of the optimal trajectory of the HSO entry into the atmosphere. The peculiarities of the processes occurring in distant wakes are thermal and chemical nonequilibrium. The paper presents a mathematical model and calculation of the distant turbulent wake based on a semi-empirically closed system of equations for determining the first moments of hydrodynamic fields, the root-mean-square value of the pulsation field of a scalar quantity and the kinetic energy of turbulence. An integral method for calculating the system of equations of the model is proposed; the asymptotic behavior of the solution is studied under the assumption that chemical reactions are frozen; the possibility of using some models of the turbulent viscosity coefficient for calculating the turbulent wake is discussed. Based on the calculations carried out, the sections of the trajectory where the influence of thermal nonequilibrium is most significant were determined.