2003 Fiscal Year Final Research Report Summary
Investigation of Thrust Performance and Physical Phenomena in Laser Propulsion
| Project/Area Number |
12450393
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Aerospace engineering
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| Research Institution | The University of Tokyo |
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Principal Investigator |
ARAKAWA Yoshihiro The University of Tokyo, School of Engineering, Professor, 大学院・工学系研究科, 教授 (50134490)
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| Co-Investigator(Kenkyū-buntansha) |
INUTAKE Masaaki Tohoku University, School of Engineering, Professor, 大学院・工学研究科, 教授 (90023738)
KOBAYASHI Tsuruo The University of Tokyo, School of Engineering, Research Assistant, 大学院・工学系研究科, 助手 (90215343)
KOMURASAKI Kimiya The University of Tokyo, School of Frontier Science, Associate Professor, 大学院・新領域創成科学研究科, 助教授 (90242825)
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| Project Period (FY) |
2000 – 2003
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| Keywords | Laser propulsion / Space propulsion / Plasma / Thrust performance / Electric discharge |
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| Research Abstract |
In this work a continuous wave (CW) laser thruster has been developed in order to establish scaling laws of thrust performance for realizing laser propulsion system. Optical diagnostic techniques were used to investigate physical phenomena of laser sustained plasmas (LSP), such as laser absorption and heating processes, ionization and excitation phenomena, heat transfer and energy dissipation processes. In addition, a 1Kw-class laser thruster was designed and fabricated to measure thrust and performance by varying the operating parameters such as propellant species and flow rate, laser input power and to examine the relation between thrust performance and the physical phenomena described above.
At first specific impulse and energy conversion efficiency of the CW thruster were obtained by thrust measurement. Also, fundamental characteristics of its thrust performance were investigated.
Secondly, optical diagnostics of laser plasmas were conducted to obtain plasma properties such as electron temperature, plasma density, and their spatial distributions.
Thirdly, influence of LSP properties on thrust performance was examined. It was found that the flatter profile of the high temperature region leads to the higher thrust performance. The best performance was obtained with a multi-focused condensing lens, which expands the size of the LSP, particularly in the axial direction. Moreover, an analytical study on oscillation phenomena suggested that the stable operations would require the control of the oscillation.
Finally specific impulse of 300 s with argon as the work gas was successfully demonstrated, which corresponds to specific impulse of more than 1000 s in case of hydrogen gas. It resulted in three times larger specific impulse compared with chemical rocket propulsion.
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