Method for processing the results of cavitation tests of TNA pumps in order to obtain an approximating function

When designing rocket engines, the problem of providing the specified basic design parameters is solved. In connection with the increase in requirements for products of rocket and space technology, the requirements for ensuring the energy efficiency of all its constituent elements are also increasing. As a rule, the task of increasing the energy characteristics of a rocket engine is carried out by increasing the pressure in the combustion chamber and the rotational speed of the turbopump shaft. An increase in the rotational speed of the shaft of a turbopump unit requires the provision of a cavitation-free operation of the pump with the absence of cavitation breakdown. This problem can be solved in various ways: by constructive improvement of the pump or by increasing the pressure parameter at the pump inlet. However, too much increase in inlet pressure is not possible, as this will increase the thickness of the walls of the rocket's fuel tanks and a corresponding increase in the mass of the entire rocket. Turning on the screw, although it does not guarantee cavitation-free operation at any inlet pressure, is the most preferred method. The geometry of the bore part of both the screw prepump and the pump blades is designed to ensure non-cavitational operation. When designing, at the stage of experimental testing of pump modes, it is possible to use the methods of computational fluid dynamics (Computational Fluid Dynamics, CFD). These methods are used in various areas of general engineering and have proven themselves well. However, the rocket motor pump has a high pressure drop with relatively small dimensions. The question arises of adapting CFD methods to modeling cavitation tests. This work is aimed at deriving a function approximating the THA pump test data set with a view to its further adaptation for CFD methods.