The Research On The Efficient Focusing Technique Of Micro-thrust-stp

The folding and deployable umbrella-shaped keel has been developed and used in solar thermal thruster (STP) system. This improved concentrator has the capability of overcoming the shortcomings of traditional inflatable concentrator, such as massive existences of superimposed fold, low deployment degree and high optical aberration, as well as the disadvantages of rigid fixed concentrator, such as its low power, huge size and mass. A deployable solar paraboloid concentrator, having the collapsible umbrella-shaped keel, power of 100 kW and aperture radius of 4.9m, has been designed and FLUENT software has been adopted to investigating on performance of STP system equipped with the concentrator above. The results revealed that the thrust and specific impulse can reach 10.23N and 691.4s respectively, indicating this system has the characteristics of high specific impulse and moderate thrust, as well as is applicable to attitude control and orbit transfer for micro-and nano-satellites. The concentrator's finite element model has been established and the ANSYS sofrware has been adopted to perform the structure statical analysis. The results indicated that the influence of films tension and solar wind on the working shape of concentrator bas been offset to a large extent by the umbrella-shaped keel, as well as that the selected structure and materials are appropriate.In order to obtain the thrust of 0.5 N and the specific impulse of 350 s, it can be shown from the investigatation on the nano-/micro-STP system that the structure of the efficient condensing systems of mirco-thrust STP should be designed as follow:a Gregory dual reflective condensor with a collapsible umbrella keel structure has been used as primal reflector. A sapphiric refractive secondary concentrator (RSC) has been used as the secondary condensor, which is connected with multimode optical fibers through the fibre connector at the outlet. the condensed energy has been conducted to the absorbor/heat-exchanger by the triangular cone energy extractor.