Combustion Properties of High Density Fuels

A novel experimental technique has been developed to simulate combustion of liquid propellants in rocket engines. The method uses an ultrasonic nebulizer coupled to the downstream end of a shock tube, which is equipped with visible, infrared, and pneumatic monitoring devices. This system was used to initiate RJ-5 mist combustion in oxygen at around 1500 K with an associated reflected shock pressure of about 2 atm. Under these conditions, the ignition delay of RJ-5 droplets with a mean particle diameter of about 3 micron was 200 micro sec, whereas ignition delay of RJ-5 vapor in the same experiment was very short (less than 1 micro sec). The droplet ignition delay decreased with increasing temperature and was approximately 100 micro sec at 1700 K. (Author)