Improvement of the pulse-detonation technology by shortening of the run-up distance and speeding up of the propagation

2022 Fiscal Year Final Research Report

• Project/Area Number: 20H02352
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 24010:Aerospace engineering-related
• Research Institution: Hiroshima University
• Principal Investigator: ENDO Takuma 広島大学, 先進理工系科学研究科(工), 教授 (00211780)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: デトネーション / 発生 / 伝播 / 衝撃波 / 火炎加速

Outline of Final Research Achievements

A technology that shortens the deflagration-to-detonation transition (DDT) run-up distance and a technology that effectively accelerates a non-stationary detonation were experimentally studied. On the former, we found out a phenomenon that a flame is remarkably accelerated just passing through a T-shaped bifurcation, and studied this phenomenon in detail. In some cases, DDT occurred just downstream of the T-shaped bifurcation as a result of the flame acceleration there. Concludingly, we obtained a very important knowledge on the flame acceleration and DDT. On the latter, we studied the influences of a single small obstacle on the detonation cellular structure, and published the results. However, the effective acceleration of a non-stationary detonation by successive small obstacles was not successful because the tentative deceleration just downstream of each obstacle was more significant than the expectancy whereas the acceleration occurred after the deceleration as expected.

Free Research Field

反応性気体力学

Academic Significance and Societal Importance of the Research Achievements

本研究は、流路内の燃焼波に流路形状が及ぼす影響に関するものである。過去のデトネーションと流路内障害物との相互作用に関する研究では障害物がセル幅（デトネーション波面の特性長）よりも大きな場合を扱っていたが、本研究ではセル幅よりも小さな障害物を扱った。これは新たな視点の研究であり、学術的に意義深い。さらに、これまでよりも現実的な流路内障害物を模擬しており、安全の視点から社会的にも意義深い。また、本研究では火炎がＴ字分岐を通過するだけで火炎加速と、条件によってはデトネーションへの遷移が起こることを見出しており、学術的にも安全という視点から社会的にも、基礎的な実験の成果として大きな意義を持つ。