Experimental studies of correction propulsion system elements for small space vehicles manufactured due to additive method

摘要

Producing ammonia correction propulsion system (CPS) elements for maneuvering satellite platforms (MSP) of small space vehicles (SSV) is a relevant problem. The investigation is devoted to the solution of the named problem with the use of direct metal laser sintering (DMLS) method. The research objective is to confirm the feasibility of manufacturing ETMT and CPS evaporator with autonomous heating elements (AHE) by DMLS method, based on the prototypes experimental testing. During the research the following tasks were solved: creating 3D models for ETMT and double-threaded evaporator and producing experimental prototypes by DMSL method. 3D models of ETMT and evaporator casings were developed following the prototypes produced by the conventional methods of turning and milling. 3D models of ETMT and evaporator casings represent complex integral parts with multiple passages for working medium flow. Experimental studies of ETMT and the evaporator were performed with nitrogen as a working medium. ETMT and evaporator temperature characteristics were determined during the experiments. The investigation was made of ETMT with nominal thrust of 30 mN and power consumption in the range of 5-60 W with and without heat insulation. AHE with embedded thermocouples, having the diameter of 6 mm and power consumption of 60 W, was used. AHE temperature was limited by 973 K. A double-threaded evaporator was investigated for power consumption of 5-30 W, the evaporator casing temperature limited by 393 K. The maximal increase in the gas temperature equaled no more than 8.6 % at the nozzle exit in the power consumption range of 10-60 W for ETMT with heat insulation. At ETMT power consumption of 5-50 W, the build-up time for ETMT was 400-600 s. While at power consumption of 50-60 W, it was 200-400 s. At power consumption of 10-30 W, the evaporator casing temperature reached 393 K in 100-340 s, AHE temperature being 400-460 K and the gas temperature at the evaporator throttle exit being no more than 290 K. At power consumption of 5 W, the maximum evaporator casing temperature of 375 K was reached in 1200 s, AHE temperature being 370 K and the gas temperature at the evaporator throttle exit being no more than 302 K.