### Experimental evaluation of rational parameters of pre-acceleration to ensure liquid sustainer engine launch in zero gravity

**Published:**26.09.2019

**Authors:** Sapozhnikov V.B., Polyanskiy A.R., Korolkov A.V.

**Published in issue: **#9(93)/2019

**DOI: **10.18698/2308-6033-2019-9-1916

**Category:** Aviation and Rocket-Space Engineering | **Chapter:** Thermal, Electric Jet Engines, and Power Plants of Aircrafts

The paper presents the results of experimental studies of liquid fuel deposition processes in liquid rocket propulsion system tanks under the conditions of free, i.e. unperturbed, orbital and suborbital flight under the influence of small prestart G-load created by auxiliary engines before liquid sustainer engine launch. Having conducted the dimension analysis, we formed the structure of dimensionless groups, which determine the dependence of the time required for fuel deposition to the tank intake, on the g level, the degree of tank filling and the physical properties of the propellant. Experimental studies were carried out on a zero gravity test bench, using the principle of implementing below-G conditions at the free fall of the equipment under test, and on a laboratory aircraft at the "Kepler's parabola" flight. The results of experimental studies have shown that the effect of viscosity on the deposition rate is practically absent. At the same time, in experiments it was found that, starting with Bond numbers exceeding 40 ... 50, the dimensionless separation time does not depend on Bond number, the value of the latter being determined by the minimum radius of free gas inclusions, deformed during when ascending during the separation process. Findings of research show that with a considerable duration of the prestart G load pulse, the movement of gas bubbles in the liquid under the action of a G load pulse becomes quasistationary.

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