A new methodology of ejector’s bench research for liquid-propellant rocket engine testing

Ejectors (jet pumps, jet devices) are used in various branches of engineering. They are used in fuel supply systems and in firing bench tests of liquid-propellant rocket engines. Ejectors are also widely used in test benches for fire tests of rocket engines to create a vacuum at the exit section of the jet nozzles (to simulate high-altitude conditions), noise attenuation, and neutralizing fuel combustion products. Ejectors can also be used in air breathing rocket engines and as booster pumps in liquid propellant rockets. Being in its configuration a section of the pipeline, the ejector fits well into the design of the rocket engine, and its installation leads only to a small increase in the mass device. There are different types of ejectors, for example, liquid jet pumps and liquid-gas ejectors. It should be noted that the fluid capacity pumped out by the ejector can vary significantly during operation. Therefore, for rational operation it is necessary to choose the most suitable flow part of the ejector. Despite the simplicity of the design, many issues of the workflow of the ejector and increasing its efficiency currently remain unexplored. The existing technique and laboratory bench allow you to take the characteristics of the ejector under atmospheric conditions at the receiving chamber of the jet apparatus. Since in practice there are often high-pressure conditions at the receiving chamber of the ejector, the question arises of the modernization of laboratory equipment and the creation of a new technique to investigate the jet apparatus under these conditions. To solve this problem, the task was set to create a new laboratory stand. As the result a new laboratory bench is constructed, which implies the creation of increased pressures at the receiving chamber of the ejector, by creating high pressures in the fluid tank with gas and redirecting it to the ejector. After the fluid and gas pass through the dif-fuser, a water-gas mixture is formed, which subsequently falls back into the tank, where it is divided into two phases and then the reverse circulation takes place. The laboratory bench has low maintenance costs and small size. © 2021, Univelt Inc. All rights reserved.