DETERMINATION OF THE OPTIMUM DESIGN OF THE MEANS TO ENSURE FUEL CONTINUITY USING THE METHOD OF NUMERICAL SIMULATION

Abstract

Residues of liquid propellant components in the power system of the propulsion system at the end of the operation of the launch vehicle stage significantly affect its energy characteristics. The fuel continuity features found in modern launch vehicle tanks ensure a continuous supply of propellant components from the tank to the propulsion system without disrupting flow and mini- mizing residues. In the fuel tank of launch vehicles, the presence of a tunnel pipeline complicates, and in certain cases excludes the possibility of taking fuel from the pole of the tank. Solving the problem of fuel intake, in this case, allows the use of means to ensure the continuity of fuel of the side type. However, the use of such a device, due to the displacement relative to the pole of the bottom of the tank by a certain angle of the sampling point, can lead to an uneven level of breakthrough and immersion of the boost gas at the inlet to the flow line and, as a result, a significant increase in the remainder of the fuel components. The authors searched for and substantiated the optimal design of the means for ensuring fuel continuity on the example of the fuel tank of the first stage of the Cyclone-4 launch vehicle, which is equipped with a side-type fuel continuity means in the form of a profiled plate (plate). The designs of siphon and annular fuel continuity means are considered. An analytical calculation was carried out using empirical dependences, a physical experiment, and a numerical simulation of their main parameters. Based on the work performed, a comparative analysis of the change in the energy characteristics of the launch vehicle depending on the chosen design was carried out. The efficiency of the operation of the considered means of ensuring the continuity of the fuel is determined in terms of the mass parameter of the remainder of the propellant components under static conditions. The result of the experimental and computational-analytical work was to obtain the most optimal variant of the fuel continuity means, which turned out to be a siphon according to several parameters. The introduction of a siphon means of ensuring continuity, as more optimal, into the design of the fuel tank of the Cyclone-4 launch vehicle will improve its energy characteristics by increasing the mass of the output payload by 5.4 kg. Also, using the numerical modeling methods (CFD methods) for design work on devel- opment, optimization, and improvement, instead of empirical and semi-empirical dependencies, allows you to: obtain more accurate results; reduce the number of experimental designs; reduce the required number of tests; reduce the duration of exami- nations; reduce the total duration of computational and design and experimental work; reduce the overall material and technical costs and, as a result, reduce the final cost of the development product, which will increase its competitiveness.