激光切割用拉伐尔喷嘴的设计分析与实现

Design analysis and realisation of Laval nozzle for laser cutting

应用阶面层理论和小扰动稳定性理论提出并分析激光切割前沿熔融层控制方程，认为熔融层流动趋于稳定的条件是由切应力驱动流动而非压力驱动流动或压力驱动流动为流动的次要因素，拉伐尔喷嘴出流特点正是流体速度高而压力较低，结合激光对喷嘴的特殊要求，提出了激光切割用拉伐尔喷嘴的设计依据和设计步骤，以及保证喷嘴正常工作所需的操作参数选取范围。

Deriving and analyzing the governing equation of the molten layer on cutting front with theory of the boundary layer and the perturbation method, we consider that a sta-ble molten stream need to be driven by friction forces but not the pressure gradient of the gas flow,or the pressure gradient is second factor. The flow feature of Laval nozzle is just as the above mentioned condition, taking account of the special demand in accordance with laser proccssing, we derive the design regulation and procedure of Laval nozzle used in laser cut-ting,and the area of operating parameter which guarantees the work normal of the nozzle.