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Advances in Aircraft and Spacecraft Science Volume 4, Number 3, May 2017 , pages 281-296 DOI: https://doi.org/10.12989/aas.2017.4.3.281 |
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Investigation of axial-injection end-burning hybrid rocket motor regression |
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Yuji Saito, Toshiki Yokoi, Lukas Neumann, Hiroyuki Yasukochi,
Kentaro Soeda, Tsuyoshi Totani, Masashi Wakita and Harunori Nagata
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| Abstract | ||
| The axial-injection end-burning hybrid rocket proposed twenty years ago by the authors recently recaptured the attention of researchers for its virtues such as no s (oxidizer to fuel mass ratio) shift during firing and good throttling characteristics. This paper is the first report verifying these virtues using a laboratory scale motor. There are several requirements for realizing this type of hybrid rocket: 1) high fuel filling rate for obtaining an optimal s; 2) small port intervals for increasing port merging rate; 3) ports arrayed across the entire fuel section. Because these requirements could not be satisfied by common manufacturing methods, no previous researchers have conducted experiments with this kind of hybrid rocket. Recent advances in high accuracy 3D printing now allow for fuel to be produced that meets these three requirements. The fuel grains used in this study were produced by a high precision light polymerized 3D printer. Each grain consisted of an array of 0.3 mm diameter ports for a fuel filling rate of 98% .The authors conducted several firing tests with various oxidizer mass flow rates and chamber pressures, and analysed the results, including s history, using a new reconstruction technique. The results show that s remains almost constant throughout tests of varying oxidizer mass flow rates, and that regression rate in the axial direction is a nearly linear function of chamber pressure with a pressure exponent of 0.996. | ||
| Key Words | ||
| hybrid rockets; stabilized combustion; regression characteristics | ||
| Address | ||
| Yuji Saito, Toshiki Yokoi: Graduate school of Engineering, Hokkaido University, Japan Lukas Neumann: Faculty of Engineering, Technical University of Berlin, Germany Hiroyuki Yasukochi, Kentaro Soeda: Institute for Photon Science and Technology, The University of Tokyo, Japan Tsuyoshi Totani, Masashi Wakita and Harunori Nagata: Faculty of Engineering, Hokkaido University, Japan | ||
