DEVELOPMENT OF THE DEVICE FOR CONTROLLING AND MEASURING THE SUPPLY OF WORKING GAS FOR LABORATORY TESTING OF THE ELECTRIC PROPULSION THRUSTERS

Abstract

The object of the research is a device for measuring, controlling, and indicating the flow rate of working gas during laboratory testing of electric propulsion systems for space applications. The problem lies in the need to ensure high accuracy in controlling and measuring the flow rates of working gas for such devices. The obtained results include: analysis of existing industrial flow meters that could be used in development; proposed structural and functional diagrams of the device; experimental investigations into the accuracy of the developed device. Based on the analysis of parameters of the most common flow meters for development, the Bronkhorst F-201CV-100-AAD-22-V regulator was selected. Based on the selected regulator, a device was developed with a 32-bit ARM architecture. This architecture provides for the use of floating-point calculations, easy reprogramming of the device, and fast indication of values displayed on the indicator. The device features galvanic isolation between the control bus and the UART port of the microcontroller. The device allows for regulation, measurement, and indication of the flow rate of working gas into the anode block and hollow cathode during testing of Hall thrusters. Using the device allows for recommendations regarding the design of onboard systems for supplying working fluid to electric rocket propulsion systems. Based on the presented development and conducted research, laboratory prototypes of the devices were manufactured. The measurement error throughout the entire range of working gas flow rates does not exceed 0.7%. The overall error of the stand control and measurement system for working gas flow rates is up to 3%. The developed device provides measurement accuracy that satisfies the developers of electric propulsion systems.