Experimental research of the performance and pressure gain in continuous detonation engines with aerospike nozzles

Abstract

Several continuous detonation engines (CDEs) with aerospike nozzles were designed, and nearly 100 effective experimental tests with methane/GOX were carried out. All tests exhausted to sea level backpressure and were conducted using a calibrated thrust stand and Coriolis mass flow meters. Throughout testing, three key parameters (area ratio, equivalence ratio, and mass flux) affecting CDE operability are discussed in detail. Three normalized parameters were proposed and analyzed to evaluate the performance of CDEs, called the normalized characteristic velocity, the normalized thrust coefficient, and the normalized specific impulse. A new evaluation method for total pressure gain is proposed and implemented. The experimental results showed that lower area ratio (less than 20%) and lower mass flux contribute to form a stable detonation and enjoys a wider range of equivalence ratio. The studied CDEs presented higher performance in the range of area ratio 12.8% - 18.8% and equivalence ratio 1.0 - 1.2. The pressure gain of detonation mode ranged between 15% and 25%, and decreased slightly with the increase of equivalence ratio (0.7 - 1.2). A suitable area ratio is necessary to improve the pressure gain.