The paper presents the results of numerical simulations of high-velocity turbulent air flows in a plane channel with a variable cross section exhibiting sudden expansion with allowance for coupled heat transfer with copper plates modeling the sensitive elements of heat flux sensors. The simulations are performed for conditions of a high-enthalpy short-duration wind tunnel whose specific features are the short duration of the test regime and unsteady “falling” conditions at the model channel entrance. The wave structure of the supersonic flow, which affects the heat fluxes at the walls, is analyzed for various Mach numbers at the model channel entrance. The numerical algorithm is validated on the basis of experimental data on heating of the sensitive elements of heat flux sensors for unsteady input conditions at the channel entrance. The influence of the Mach number, static parameters, and stagnation parameters on the rate of heating of the sensitive elements located at various points in the channel is studied numerically. The heat fluxes calculated under constant and “falling” conditions at the channel entrance are compared. It is shown that the accuracy of heat flux modeling can be increased by taking into account the intensity of oscillations of the flow parameters and their changes along the channel.

本文介绍了具有可变横截面的平面通道中高速湍流气流的数值模拟结果，该通道表现出突然膨胀，并允许与模拟热通量传感器敏感元件的铜板进行耦合传热。模拟是针对高焓短时风洞的条件进行的，其具体特征是测试状态持续时间短以及模型通道入口处的不稳定“下落”条件。针对模型通道入口处的各种马赫数，分析了影响壁部热通量的超音速流的波结构。该数值算法根据通道入口处非稳态输入条件下热通量传感器敏感元件加热的实验数据进行了验证。数值研究了马赫数、静态参数和停滞参数对位于通道中不同点的敏感元件的加热速率的影响。比较了通道入口处恒定和“下降”条件下计算的热通量。结果表明，通过考虑流动参数的振荡强度及其沿通道的变化，可以提高热通量建模的准确性。