Analysing a Numerical Calculation Adequacy of the Recovery Factor for Various Problem Statement Options

The paper studies a recovery temperature distribution in a turbulent boundary layer of the compressible gas in a rectangular heat-insulated channel in supersonic flow mode using the numerical methods of gas dynamics. The software package ANSYS Fluent was used for calculation.In the numerical simulation were used SST and k-epsilon turbulence models with two types of thermal boundary conditions on the channel wall: the standard adiabatic condition, provided by the software package, as well as the user boundary condition (UDF) based on the empirical dependence of the recovery factor in a turbulent boundary layer on the Prandtl number of the medium.A data analysis showed that an application of the standard boundary condition of a heatinsulated wall, in some cases, results in recovery factor values on the wall, corresponding to the laminar rather than turbulent boundary layer.For all options of the numerical model under consideration was found a non-zero value of the heat flow to the adiabatic wall. In the case of setting the user boundary conditions, this fact is due to the approximate nature of the dependence of the recovery factor on the Prandtl number.For standard boundary condition of an adiabatic wall the most likely explanation for this result is a feature of the numerical solution scheme, according to which, to set the zero heat flow, is used a number of ghost cells, which can lead to the heat pattern distortion in the computational domain in the vicinity of the wall.Correction of boundary conditions using an empirical relationship for the recovery factor enabled us to reduce the heat flows and have a better approximation of the adiabatic boundary condition.Thus, it follows from the data obtained that the calculation of heat exchange in a turbulent boundary layer by means of ANSYS Fluent software physically yet does not provide the adequate results, and for its update at the moment the third party experimental data are required