Detonation Dynamics in a Diverging Cone and its Application to the Pulse-Detonation Technology

2019 Fiscal Year Final Research Report

• Project/Area Number: 17H03482
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Aerospace engineering
• Research Institution: Hiroshima University
• Principal Investigator: ENDO Takuma 広島大学, 工学研究科, 教授 (00211780)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: デトネーション / 拡大流路 / パルス運転 / 溶射 / 高融点セラミックス

Outline of Final Research Achievements

For both the detonation initiation in a short distance and the enlargement of the combustor exit, we experimentally clarified the condition for that a detonation entering a diverging cone from a cylindrical tube can pass through the diverging cone. By using the results of the fundamental study, we improved our pulse-detonation thermal-spray gun so that its exit was enlarged from its original size of 10 mm in diameter to 20 or 30 mm. The improved pulse-detonation combustor was stably operated at the original frequency of 100-150 Hz. Furthermore, we demonstrated that the high-melting-point ceramics, that are difficult to be sprayed before the improvement, can be sprayed by using the improved pulse-detonation thermal-spray guns. In addition, on the spraying of materials that could be sprayed even before the improvement, the distance between the spraying-gun exit and the sprayed substrate was enlarged approximately in proportion to the exit diameter.

Free Research Field

反応性気体力学

Academic Significance and Societal Importance of the Research Achievements

デトネーションとは、通常の燃焼よりも高温・高密度・高圧の既燃ガスが生成される特殊な燃焼モードである。本研究では、デトネーションを産業応用するため、流路形状がデトネーション伝播に及ぼす影響についての基礎的な知見を得る研究を行うとともに、実際にその知見を使って溶射装置（コーティング装置の一種）を改良した。装置を改良した結果、高融点セラミックスの溶射能力が飛躍的に向上した。この溶射装置の改良により、デトネーションを利用する溶射装置の小型化が実現され、我が国の産業に役立つものと思われる。