Characteristics of low thrust liquid-propellant rocket engines testing process

Liquid-propellant rocket engines of low thrust are the main type of rocket engines for control systems of space aircrafts. The thrusters are able to work either in continuous or impulse regime, which is one of their main characteristics. The suggestion about engines` reliability should come from the results of tests which create real or greatly approximated to the real conditions. The development process of thrusters takes into a great account the problems of bench testing methodic, technical equipment of test benches for creating the closest possible conditions to the space and the using of diagnosis methods and instruments for different physical researches and dimensions. The ground test effectiveness depends on the level of imitation of real conditions and the level of attention to all working factors, that influence the credibility of reliability parameter estimation during the development. One of the most important questions in terms of testing effectiveness is the question of testing result accuracy and credibility. The testing process of thrusters mainly goes under the requested conditions of vacuum, created in pressure chambers. To increase the effectiveness of imitation of the space conditions the paper suggests the using of pressure chamber, equipped with the tube screen with the circulating liquid nitrogen under required mass flow ratio. The impulse working regime creates instability of propellant moving in pipelines. The paper considers the methods of providing the dynamically similar characteristics of supply systems in propulsion systems as well as conformity of hydraulic, inert and wave characteristics of supply pipelines.