Regenerative cooling and adjustable throat for rotating detonation engine

A method for operating a rotating detonation engine, having an outer wall extending along an axis;

• an inner wall extending along the axis, wherein the inner wall is positioned within the outer wall to define an annular detonation chamber having an inlet and an outlet, the method comprising:
• flowing liquid phase fuel along at least one wall of the inner wall and the outer wall in a direction from the outlet toward the inlet to cool the at least one wall and heat the liquid phase fuel to provide a heated liquid fuel, wherein the fuel is selected from a group consisting of aviation fuel, CH4, C2H4 and combinations thereof;
• flowing the heated liquid fuel to a mixer at the inlet and through at least one fuel orifice of the mixer to reduce pressure of the heated liquid fuel, flash vaporize the heated liquid fuel and mix flash vaporized fuel with oxidant to produce a vaporized fuel-oxidant mixture;
• feeding additional fuel to an additional inlet to the annular detonation chamber that is located along a length of at least one of the inner wall and the outer wall and spaced along the axis toward the outlet from the inlet;
• and
• detonating the vaporized fuel-oxidant mixture in the annular detonation chamber.