Updated conceptual design of hydrogen/ethylene fueled detonation ramjet: Test fires at Mach 1.5, 2.0, and 2.5

The conceptual design of a hydrogen/ethylene fueled detonation ramjet (DR) studied earlier is updated based on numerical simulations and test fires at airflow Mach numbers 1.5, 2.0, and 2.5. The goal of the design update is to increase the operation stability, reduce aerodynamic drag, and improve thrust performance at continuous detonation of hydrogen/ethylene in the DR combustor. The updated DR is fabricated and tested. The thrust performance of the updated DR is increased significantly. At on-design M = 2.0, the range of stable operation of hydrogen fueled DR combustor is expanded in terms of the air-to-fuel equivalence ratio from 1.6 to 3.3. At the air-to-fuel equivalence ratio of 3.1, the fuel-based specific impulse reached 4760 s. The maximum value of total thrust is 1000 N. At off-design M = 1.5 and 2.5, the fuel-based specific impulse / total thrust attained 2780 s / 740 N, and 3780 s / 1160 N, respectively. Replacement of hydrogen by ethylene leads to the significant narrowing of the DR stable operation domain: continuous-detonation of ethylene-air mixture is registered only for nearstoichiometric mixtures. (C) 2022 Elsevier Masson SAS. All rights reserved.