Computational experiment on obtaining the characteristics of a thermal control system of spacecraft

The presented article is covered a research task for a thermal control system with a fluid circuit (FC) including tubes with a current of the working medium inside, a radiation heat exchanger, panels with heat-generating equipment placed on them, pumps for pumping the working fluid, a flow control system. Analysis and justification of the equations involved in the calculation algorithm are presented. For the modeled sys- tem the influencing parameters are distinguished. As initial equations for modeling, equations that have a significant effect on the thermophysical parameters (temperature, flow, heat transfer coefficient) are used: the Stefan-Boltzmann law for thermal radiation; the law of heat transfer from the wall to the fluid; heat capacity equation; the equation of thermal conductivity inside the panel from the radiating surface to the surface of heat exchange between the working heat and the fluid; flow equation; criterial equation for determining the heat transfer coefficient. To verify the calculation algorithm, the calculated and experimental data on the temperatures of the fluid for the winter and summer solstices were compared. The results of the calculation have a satisfactory convergence with the experimental data. Using the calculation algorithm in the framework of the computational experiment we evaluated the effect on the FC of four influencing parameters: the heat release of the payload module, the flow rate of the working fluid, the area of the radiating panels, and the heat release of the service module. For each of these parameters exposure levels were established. For example, for heat release of the service module, 0, 50, 100, 150 and 200 % of the base load of 915 W from the pilot study were considered as load levels. The article presents the formulation of the research problem, the description of the calculation algorithm, the data obtained by calculation, the analysis of the results of the computational experiment, and conclusions on the degree of influence of the selected parameters on the operation of the FC.