For generating uniform air flow at Laval nozzle outlet

the influences of the form

velocity ratio and pressure drop of the injection was studied.An air heater with two forms of injection and a Laval nozzle were designed

then FLUENT was used to simulate the combustion and flow filed.The result show that:there is little influence from the form of the injection

which mainly influences the temperature of the injector;the lower velocity rate and oxygen drop of the jet means the more uniform of nozzle outlet and approximative contraction ratio in two directions is better for the outlet.