طراحي، ساخت و آزمون نمونه‌ي مهندسي رانش‌گر گاز سرد جهت به‌كارگيري در شبيه‌ساز سه درجه آزادي ديناميك وضعيت ماهواره

Design and Development of a Cold Gas Thruster System for use in a Tri-axial Satellite Simulator

هدف اصلي اين پژوهش، طراحي، ساخت و آزمون رانش‌گر گاز سرد با توجه به نيازهاي ماموريتي يك شبيه‌ساز سه درجه آزادي ديناميك ـ وضعيت ماهواره است. براي اين منظور، در گام نخست به شناسايي ساختار و ماموريت شبيه‌سازهاي ديناميك وضعيت پرداخته، سپس با تعريف الزامات ماموريتي شبيه‌ساز 1001 (ساخته شده در آزمايشگاه تحقيقات فضايي)، لزوم بهره‌مندي از مجموعه رانش‌گرهاي گاز سرد را به عنوان عملگرهاي زيرسيستم كنترل وضعيت در اين شبيه‌ساز تبيين مي كنيم. تشريح كامل فرايند طراحي سيستمي مجموعه‌ي رانش‌گر گاز سرد در چهار فاز طراحي مفهومي، طراحي مقدماتي، طراحي جزيي و طراحي نهايي به همراه الزامات طراحي هريك از المان ها و پروسه ساخت و آزمون تجهيزات، در اين مقاله ارايه شده است. اين فرايند در فازهاي مختلف با بهره‌گيري از معادلات اوليه‌ي طراحي، مقايسه‌ي آن ها با شبيه‌سازي هاي عددي به كمك نرم افزار فلوينت، ساخت نمونه‌ي تحقيقاتي و آزمون آن در شرايط واقعي انجام پذيرفته كه جزييات آن، در اين مقاله مورد بررسي قرار خواهد گرفت.

The main purpose of this article is to describe the design and development process of a cold gas thruster subsystem used in a tri-axial satellite simulator (Simulator 1001) as an actuator. Simulator 1001 emulates the rotational motion of a satellite in orbit and acts as a test-bed for satellite attitude determination and control subsystem design and development. Among these projects, the simulator platform (spherical air-bearing) and several subsystems (cold gas micro-thrusters, on-board processor, attitude sensor, balancing mechanism, high-pressure composite tanks, efficient regulator and etc) has been designed and manufactured (or provided) by our technical team in the Space Research Laboratory of KNT. By considering the limitations and requirements of the main project, design and manufacture of a simulator 1001 system design procedure of a cold gas thruster subsystem was established. Systems engineering design procedures encompass the tools and methodology necessary to move conceptualization to system implementation, with emphasis on the system as a whole, and user needs. It has four main phases: conceptual design, preliminary design, detailed design and final design. In the conceptual phase, by reviewing the available samples of cold gas thrusters and using gas dynamics theories, the main coordinates of a cold gas thruster subsystem, including: quantity, tank pressure, regulator pressure, nozzle diameter, expansion ratio and etc., are estimated. In the next phase, the preliminary design, numerical simulation and analysis of gas flow using Fluent software is performed, and the final specifications of the prototype thruster model are exported. Manufacturing the prototype model and the thrust-stand-test are performed in a detailed design phase. Also, evaluating the thrust level of the protype model and finalization of other component specifications, such as tank, regulator, accumulator, solenoid and driver, are the main parts of this phase. In the next phase, the final design, drawings of the thruster and solenoid are prepared and software or user interfaces are built. The outputs of this phase are suitable and also complete for manufacturing the system. In this paper, the above phases will be explained, and results of the test procedure of the sophisticated cold gas thruster will be presented and analyzed precisely.