|Budget Amount *help
¥1,500,000 (Direct Cost : ¥1,500,000)
Fiscal Year 1997 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1996 : ¥900,000 (Direct Cost : ¥900,000)
Supersonic cmbustion of hydrogen gas, which was injected transversely from a circular hole flush to the wall of a high temperature/high speed wind tunnel (stagnation temperature 1500K max., Mach number 1.8), has been investigated. The experimental study consists of combustion tests due to (1) hydrogen injection with elevated temperature (2) chemical radicals injection using a plasma torch.
The effect of elevating injectant temperature up to 950K by using a heater system has been recognized upon the near-injector combustion in the airstream of 1400K.The bulk flame downstream, homever, was not much affected by this injectant temperature, but found to be rather sensitive to the main airflow temperature. The flame formed inside the test section showed a tendency of strong interaction with the shock waves, which enhanced the combustion at the corresponding interaction point.
The plasma torch employed Argon as the carrier gas and Oxygen as the secondary additive gas, which operated in the airflow of 1000K.The combustion tests were not successful for the torch to be located upstream of the fuel injector, but realized the ignition at the temperature of 800K,that is, far below the usual self-ignition temperature of 1300K.It has been also shown that the additive Oxygen radicals further lowered the ignition temperature to 600K,which showed a little unstable feature. The bulk flame in this case is also enhanced due to the interaction with the shock waves inside the test sectoon.