Study of the Propane Detonation Spraying under Different Gun Structures

Detonation spraying is a technique that uses the high-temperature, high-velocity detonation waves to deposit the molten metal particles onto the target surface. The effect of the detonation spraying is influenced by the structure of the gun significantly. A series of detonation spraying gun two-dimensional (2-D) numerical models with various spray gun structures (slope lengths from 5 to 45 mm with a step of 10 mm) were established in this work, to investigate the spray performance. During the process of gas detonation, the interaction between the detonation wave and obstacles results in the generation of reflected waves, which exerts an accelerating effect on flame. Simultaneously, collisions between the flame front and obstacles introduce energy losses. Based on the above factors, the following results can be obtained: when the slope length at the nozzle diameter change point is 5 mm, the maximum flow velocity is achieved at the spray gun outlet. When the slope length at the transition point of the spray gun is 25 mm, the maximum temperature is reached at the spray gun outlet. When the slope length at the transition point of the spray gun is 45 mm, the maximum pressure is reached at the spray gun outlet. This work can contribute to the design of the detonation gun.