Investigation of the relationship between combustion efficiency and total pressure gain for RDE

Abstract

Total pressure gain is an important parameter in RDC engineering applications. Many factors affect the total pressure gain, such as the area ratio of the outlet to the inlet (A8/A3.1) and type of fuel. In this study, convergent–divergent slot and Tesla valve inlet configurations were adopted. Three convergent nozzles were used, and the ratios of the outlet area to the combustor cross-sectional area (A8/A3.2) were 0.65, 0.5, and 0.25, respectively. The experiments were conducted at mass flow rate of 1.5 kg/s, 1.3 kg/s, and 1.0 kg/s. The combustion efficiency and total pressure gain were calculated using the temperature increase and Mach-corrected static pressure (MCSP). When A8/A3.2 is 0.25, most of the propagation modes are longitudinal pulsed detonations (LPD). The combustion efficiency increased with the equivalence ratio within the range of the detonation boundary. A model was developed to describe the relationship between combustion efficiency and total pressure gain. Once the configuration of the RDC is fixed, a proportional relationship exists between the combustion efficiency and total pressure gain. Improving combustion efficiency enhances the total pressure gain.

Keywords

• RDE
• Total pressure gain
• Combustion efficiency
• Mass flow function