Study on the performance characteristics at off-design points of an axially symmetric plug nozzle
| Autor: | Azuma, Nobuyuki, Tanatsugu, Nobuhiro, Sato, Tetsuya, Kobayashi, Hiroaki, Hongo, Motoyuki |
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| Jazyk: | japonština |
| Rok vydání: | 2004 |
| Předmět: | |
| Zdroj: | 宇宙輸送シンポジウム 平成15年度 = Proceedings of Space Transportation Symposium FY2003. :139-142 |
| Popis: | In the present study were examined numerically and experimentally the off-design performance characteristics on an axisymmetric plug nozzle with variable throat area. In this nozzle concept its throat area can be changed by translating the plug in the axial direction. First, the mixed-expansion plug nozzle, in which two expansion parts are arranged both inside and outside, was designed by means of the method of characteristics. Secondly, the CFD analysis was verified by the cold-flow wind tunnel test. Thirdly, its performance characteristics were evaluated over wide range of pressure ratio from half to double throat area through the design point, using CFD code verified by the wind tunnel tests. It was made clear from the study that not so critical thrust coefficient efficiency losses were found and the maximum thrust efficiency loss was approximately 5 percent at most under off-design conditions without external flow. It implies that a plug nozzle possesses the altitude compensation even under the off-design geometry operations. However, shock waves were observed at the inner expansion part in case of the doubled throat area case and thus some thermal problems may be caused on the plug surface. Furthermore, collapse of the shock cell structure on the plug surface was observed with external flow (around Mach number 2.0) as it became lower pressure ratio below the design point and the fact may result in big efficiency loss regardless of configurations. 資料番号: AA0047118035 |
| Databáze: | OpenAIRE |
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