目的 研究高压冷喷涂中，送粉气流在室温时主气流温度对冷喷涂粒子速度和温度的影响。方法 利用计算流体力学软件FLUENT对冷喷涂流场进行数值模拟，分析不同送粉压差、不同喷管喉部直径的情况下，主气流温度对气体流场、粉末速度和温度的影响状况。结果 送粉压差为0.1 MPa且喷管喉部直径为2 mm时，进入喷管的送粉气流流量占总气流流量的比值超过50%，此时提升主气流温度对冷喷涂粒子撞击速度和温度的提升幅度十分有限。在不改变送粉气流流量的情况下，增加喷管喉部直径可有效削弱送粉气流对粒子加速的不利影响。结论 考虑送粉气流时，主气流温度对冷喷涂粉末沉积效果较弱，为了提高冷喷涂粉末沉积效率应保证顺利送粉的前提下尽可能地减小送粉气流流量，并且在设计喷管时应适当增加喷管喉部直径。

Objective To study the effects of main gas temperature on speed and temperature of particles under the condition that the powder carrier is at room temperature in high pressure cold spraying. Methods The effects of main gas flow temperature on gas flow field, powder speed and temperature within different pressure differential and different size of nozzle throat were investigated based on numerical simulation of cold spraying field with computational fluid dynamics software Fluent. Results When the pressure differential was 0.1 MPa and the diameter of the nozzle throat was 2 mm, the ratio of the mass flow of powder carrier gas on the total mass flow of the gas in nozzle exceeded 50%. At this time the increasing range of the particles impact velocity and temperature was limited with the increasing of the temperature of main gas. Using nozzle with larger size of throat could weaken the adverse effects effectively of powder carrier gas on particle accelerating. Conclusion The effect of main gas temperature on powder deposition is weakened when the powder carrier gas is considered. In order to improve the powder deposition efficiency, the flow of the powder carrier gas should be as small as possible under the premise of normal powder feeding, and also the nozzle throat diameter should increase appropriately when the nozzle would be designed.