大口径片状放大器片箱腔内气体吹扫过程模拟

Simulation of gas purging process in the slab cassette of a large-aperture slab amplifier

为更快速地置换片状放大器片箱内部的气体、带走片箱内部因氙灯辐照产生的μm级气溶胶颗粒,以延长钕玻璃增益介质使用寿命,提出了几种不同的片箱隔板气体流道设计并对其吹扫效果进行对比。基于计算流体力学手段和分散相模型,求解了片箱腔内的吹扫流场并模拟了微米级粒子污染物的吹扫过程。片箱隔板采用开孔设计,通过对比分析发现,不同开孔孔径和排列方式的片箱吹扫效果差异明显。当开孔孔径为ϕ14 mm、且上下隔板都采用整齐排列的圆形通孔时,片箱内的气体压力损失更小(424.3 Pa)且吹扫达到百级的时间更短(205 s)。最后片箱吹扫实验显示了采用该结构的片箱其腔内吹扫达到百级的时间为2~3 min。

To replace the gas in the slab cassette of slab amplifier more quickly,thus to transport micro aerosol particles produced by xenon lamp irradiation,and prolong the operating life Nd:glass,this paper proposes several different designs of gas flow channel on the baffle of slab cassette and compares their purging effects.Based on computational fluid dynamics(CFD)and dispersed phase model(DPM),the purge flow field in the chamber was obtained,and the purging process of micro contaminant particles was simulated.Through comparative analysis,it is found that the time required to achieve a cleanliness of 100 class is significantly different for different apertures and arrangements of the holes.When the hole diameter is 14 mm,and the holes on the upper and lower baffles are orderly round through-holes,the purging time to achieve 100 class is 205 s,and the gas pressure loss in the cassette is 424.3 Pa.Finally,gas purging experiments of a 4×2 combined slab amplifier show that a purging time of 2−3 min is needed to achieve 100-class cleanliness by the optimized design.