Experimental investigation on the application of the coal powder as fuel in a rotating detonation combustor

Detonation cycle realizes the high-efficiency utilization of the fuel. However, most of the fuel considered in the detonation engine is gaseous or liquid fuel, while seldom notice is focused on the solid fuel which is also a kind of important energy resource. In this research, experiments were conducted in a rotating detonation combustor, separately fueled with the coal/H2/air and the H2/air to realize the operation of PRDE (Powder Rotating Detonation Engine) and GRDE (Gaseous Rotating Detonation Engine) with the global equivalence ratio ranging from 0.7 to 1.7. By comparing and analyzing the detonation characteristics and engine performance of the PRDE and GRDE, the specific feature of the coal PRDE is revealed. It's found that the coal powder increases the detonation height; a small amount of the coal powder increases the detonation velocity while excessive coal powder decreases the detonation velocity; with the proper increase of the coal powder, the pressure peak increases and the thrust of the PRDE correspondingly improve, which indicates that the coal powder takes part in the detonation combustion and strengthen the detonation intensity, making a contribution to the engine performance. However, with the excessive addition of the coal powder, more powders would be burnt after the sonic plane and thus the specific impulse is decreased.