Spatial Stabilization of Detonation Wave Sustained by Photon Injection and Its Application to Supersonic Combustor

1999 Fiscal Year Final Research Report Summary

• Project/Area Number: 10450372
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Aerospace engineering
• Research Institution: Nagoya University
• Principal Investigator: FUJIWARA Toshitaka Nagoya University, School of Engineering, Professor, 工学研究科, 教授 (90023225)
• Co-Investigator(Kenkyū-buntansha): LEBLANC E.Joseph Nagoya University, School of Engineering, Research Associate, 工学研究科, 助手 (30283419) ; ENDO Takuma Nagoya University, Center for integrated Research in Science and Engineering, 理工科学総合研究センター, 助教授 (90232991) ; YOSHIKAWA Norihiko Nagoya University, School of Engineering, Assistant Professor, 工学研究科, 助教授 (60135423) ; SHIRAISHI Hiroyuki Nagoya University, School of Engineering, Research Associate, 工学研究科, 助手 (50273272)
• Project Period (FY): 1998 – 1999
• Keywords: Detonation / Combustion / Propulsion / Photochemical Reaction

Research Abstract

Generation of free radicals by photochemical means can stabilize the detonation wave and this mechanism has a potential of improving the performance of supersonic combustion engine. The present research pursues the fundamental aspects of the photon-injected detonation wave and the effects of free radicals injections to fresh gas mixtures. The important results of the present research are summarized below.
(1) Photochemical ignition phenomena in hydrogen-chlorine mixtures
The ultra-violet irradiation of 355nm of the 3rd harmonic of Nd : YAG laser is used to induce the photochemical dissociation of chlorine molecule into chlorine atoms. Volumetric ignition of the mixture is achieved due to the reaction enhancement. The ignition phenomena are observed by high-speed photography. The experimental results are compared with the computational analysis of elementary reaction mechanisms.
(2) Manufacture of supersonic wind tunnel
A supersonic wind tunnel of blow-down type is designed and constructed. About 15 seconds of Mach 2.5 supersonic flow is planned using a 1 mィイD13ィエD1 tank at 30 atm. The two-dimensional supersonic nozzle and the connecting observation part of 4 inch x 4 inch cross-section is carefully designed. The manufacture of the system is completed, and the fundamental performance of the wind tunnel is preparation.
(3) Computations of enhancement effects of free radicals injection
Free radicals are assumed to be directly injected to hydrogen-air and methane-air mixtures. The subsequent reaction processes are computed including elementary reactions. The free radicals injection effectively reduces the induction times. Reaction path changes increasing the pressure of the gas mixture.