Investigation of 11D428А-22 thruster operation dynamics with bellows flow stabilizer

This paper presents the results of comparative fire test investigations of the bipropellant thruster 11Д428А-22 with both plate and bellows flow stabilizers. The direct-acting bellows flow stabilizer 11Д428А.410.00/-01 presented in this paper meets all current requirements and progress trends of such type of hardware. In the developed stabilizer the bellows is used as a sensitive element, which excludes any uncontrollable leakages of a working medium and improves the reliability by eliminating cramping and varying frictional forces typical for pistons and plungers. The use of bellows-expanding spring at an initial state of the stabilizer extends the regulation range of the latter and increases the maintenance accuracy of specified flow over the entire control range. The flow stabilizer provides the starting propellant flow at the expense of added mass; hence the negative regulator effect becomes the favorable one in respect of a feed pipeline of liquid propellant thruster to improve thruster operation dynamics. Novelty of the flow stabilizer configuration is combining functions of a regulator and a starting device and broadening a regulation range and accuracy due to the spring expands the bellows at the initial state. The development construction is easy to fabricate and it provides the agreement of calculated regulator parameters and those resulted at the tests.