Is there a distinct flame-front in a liquid-fuelled rocket combustion chamber?

Question

Liquid fuel and liquid oxidizer are injected at high pressure through small orifices into the 'top' of a rocket's combustion chamber. The intention is that these mix quickly and then burn completely before exiting the combustion chamber and entering the engine bell. I am wondering if this combustion occurs in a fairly well-behaved manner with a distinct flame-front, a distinct region where the mixture is burning, and a distinct point where the combustion is essentially complete? Or does the whole process necessarily (or inadvertently) involve large-scale turbulence in the combustion chamber - perhaps to ensure adequate mixing and complete combustion? As a secondary question, how does the combustion behavior change as the engine is throttled? Is it this behavior that constrains how far a rocket engine can be thottled back?

Answer 1

Partial answer because

• based on a simulation
• doesn't address the secondary question about changes with throttling

The paper CFD SIMULATION OF A LIQUID ROCKET PROPELLANT (LH2 /LOx) COMBUSTION CHAMBER shows a "flame front" in the sense that majority of the combustion reactions take place in a relatively small area of the combustion chamber.

(zero on the x-axis is the throat)