轴快流CO2激光器翅片管换热器强化换热研究

为了解决厚板切割领域中高功率轴快流CO₂激光器翅片管换热器压力损失大、传热效率低的问题，采用计算流体力学软件ANSYS分析了3种涡流发生器的换热特性，并对换热性能更佳的梯形小翼涡流发生器的形状、长度、高度和安装角度进行优化设计；通过一个开环的风洞实验平台验证了数值模拟数据的可靠性。结果表明，长度11mm、高度2.6mm的梯形小翼涡流发生器采用30°迎角渐缩方式布置时换热性能最佳，在雷诺数为600~1600范围内，和没有安装涡流发生器相比，梯形小翼涡流发生器的努塞尔数Nu提高了8%~22%，摩擦因子上升了16%~27%；8h稳定输出功率4216W，比额定输出功率高出5.4%。该研究提高了CP4000系列激光器的厚板切割能力。

Study on heat transfer enhancement of fin-and-tube heat exchangers in fast-axial-flow CO2 lasers

In order to solve the problem of high pressure loss and low heat transfer efficiency of fin-and-tube heat exchangers in a high power axial flow fast CO2 laser in the thick plate cutting field, computational fluid dynamics software ANSYS was used to analyze the heat transfer characteristics of 3 kinds of vortex generators.The shape, length, height and angle of trapezoidal winglet vortex generator with better heat transfer performance were optimized.The reliability of the numerical simulation data was verified through an open loop wind tunnel experimental platform.The results show that the optimum heat transfer performance is gotten with trapezoidal winglet vortex generator of 11mm length, 2.6mm height and 30° angle of attack which is gradually reduced.Compared with the generator without installing vortex, the heat transfer performance of trapezoidal winglet vortex generator Nu is increased by 8%~22%, and the friction factor is increased by 16%~27%, in Reynolds number of 600~1600.Test results of CP4000 series axial fast flow CO2 laser show that the stable output power of 8h is 4216W, 5.4% higher than the rated output power.The study improves the plate cutting capacity of CP4000 series lasers.