Method for Determining Nozzle-Throat-Erosion History in Hybrid Rockets and Elucidation of the Mechanism

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H04197
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Aerospace engineering
• Research Institution: Hokkaido University
• Principal Investigator: Nagata Harunori 北海道大学, 工学研究院, 教授 (40281787)
• Co-Investigator(Kenkyū-buntansha): 戸谷 剛 北海道大学, 工学研究院, 准教授 (00301937) ; 脇田 督司 北海道大学, 工学研究院, 助教 (80451441)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: ハイブリッドロケット / ノズル浸食 / 再現法

Outline of Final Research Achievements

We developed a new reconstruction technique titled nozzle-throat reconstruction technique to estimate nozzle-throat-erosion history and oxidizer-to-fuel-mass-ratio history in hybrid rockets. Static-firing tests were carried out on a 2kN-class hybrid-rocket motor under varying oxidizer-flowrates to evaluate the accuracy of reconstructed results. For equivalence ratios from 0.6 to 1.4, the relationship between nozzle-throat-erosion rate and equivalence ratio of reconstructed results displays a trend consistent with chemical-kinetic-limited heterogeneous-combustion theory, as well as predictions made by previous researchers. Also, we selected some materials which can prevent nozzle erosion and evaluated anti-erosion characteristics by combustion experiments. As an experimental result, graphite coated by silicon carbide showed good anti-erosion characteristics for hybrid rocket nozzles.

Free Research Field

宇宙推進工学 燃焼工学