Space systems design (spacecraft, satellites, space stations and their equipment)
Hamed Hashemi Mehneh; amirreza Ghedamini Harouni
Volume 12, Issue 4 , December 2019, , Pages 1-17
Abstract
The robust multi-disciplinary, multi-objective shape optimization of re-entry capsule with aero-thermodynamic, trajectory, stability and the geometry considerations are presented in this paper. In this research, the results of maximizing the volumetric efficiency of the capsules while minimizing the ...
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The robust multi-disciplinary, multi-objective shape optimization of re-entry capsule with aero-thermodynamic, trajectory, stability and the geometry considerations are presented in this paper. In this research, the results of maximizing the volumetric efficiency of the capsules while minimizing the ballistic coefficient and the longitudinal stability derivative with considering uncertainties are discussed in presence of some constraints on geometry, heating load, and load factor. To reduce the time and cost of robust optimization, the Adaptive Monte Carlo Simulation technique is used which decreases the number of required evaluations within the robust optimization process. Utilizing the constrained multi-objective genetic algorithm will result in a collection of robust optimal solutions. The results show that the performance of obtained robust optimal configurations is in a way that the considered constraints aren’t violated with 99.8% of confidence level even in the presence of uncertainties.
Saeedeh Ya’ghob-nezhad; Seyed Hamed Hashemi Mehne
Volume 9, Issue 1 , May 2016, , Pages 73-89
Abstract
Because of vast applications of Liquid fuel engines in rockets and importance of their functional parameters such as trust, specific impulse and fuel consumption in engine performance, it is needed to be tested in different functional conditions before operation in actual missions. The analysis of test ...
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Because of vast applications of Liquid fuel engines in rockets and importance of their functional parameters such as trust, specific impulse and fuel consumption in engine performance, it is needed to be tested in different functional conditions before operation in actual missions. The analysis of test data used to improve the design, engine troubleshooting and to expand the production program for future rockets. Selecting the suitable injector(s) is the key parameter for improving combustion parameters. With respect to finding the effective ways to analyzing the engine hardware performance without neglecting from their main characteristics, one of the alternatives is doing the hot-fire tests by using a sub scaled engine instead of the full-scale engine. In this research, the design process and manufacturing details of a 300N trust (nominal) micro engine with single swirl Injector is presented. Initial firings using the actual fuel and oxide were not successful. Low fuel flow, low mixing area of the fuel and oxide, and contamination in the self ignition fuel (TR-1) were considered to be the reasons. Overcoming to these problems resulted in successful firing of the subscale engine.
