三阴极等离子体喷枪的数值模拟

摘要

多电极等离子体射流具有火焰长、稳定性高等优点，是制造可重复高性能涂层的有效方法。采用数值模拟方法，对三阴极等离子体喷枪内的流动与传热进行了三维稳态模拟。三阴极等离子体喷枪的模拟结果表明，旋流进气在三个阴极下游旋转加强，形成电弧的三角结构，同时伴随着形成三角星形结构的速度分布，与单阴极等离子体喷枪相比，在喷枪出口形成集中在中心区、速度和温度分布更加均匀的火焰。%Multi-electrode thermal plasma jet enjoys such super characters as long flame and high stability,which is an effective method of producing repeatable and high performance coatings. Three dimensional simulations were per-formed on plasma flow and heat transfer inside three-cathode plasma spray torch. Results reveal that swirl inlet be-comes stronger at downstream of cathodes,yielding a triangular structure of the arc and a triangular star-shaped gas velocity distribution at nozzle exit. Compared with single-cathode plasma torch,three-cathode plasma torch generates plasma jet flame with more uniform temperature and velocity distribution which concentrates in central part of nozzle exit.