支管带套管的横向射流流动特性的实验研究

Digital Particle Imaging Velocimetre Experimental Study of the

针对核反应堆冷却剂系统中注水用带热套管的T型接管热冲击问题 ,利用数字粒子图像测速 (DPIV)技术 ,测量了支管带套管的横向射流主流管内的流场 ,以及套管与支管间的环腔内的流场 ,考察了射流与主流流速比R为 0 .5～ 4 0时的速度和涡量分布特性 ,分析了主流管内的复杂涡系及套管环腔内的流动特性 .结果表明 ,在出射孔附近的套管环腔侧后部存在“环腔泄流” ,这有利于减弱射流对下游壁面的影响 ;射流近区的强涡主要来源于射流及环腔泄流剪切层 ,而它很快就破碎和耗散 ,发展为尾流远区的反向涡对 ;套管环腔内的流动与R密切相关 。

In order to understand the hydraulic mechanism of thermal shock caused by cold jet injection in a T-junction with thermal sleeve in the reactor cooling system, experiments were carried out on the jet-to-cross flow with a sleeve tube by using the digital particle imaging velocimetre (DPIV) to measure the flow in the main duct and in the annular space of the sleeve tube. The velocity and vorticity distributions were investigated at the jet-to-cross flow velocity ratio R of 0.5-4. The complex vortical structures in the main duct, together with the flow characteristics in the sleeve annular, were analyzed. It was found that, from the annular space at the rear part of the sleeve near the jet exit, there was a stream of discharge, which was in favor of decreasing the influence of jet on the downstream wall. The intensive vortex in the near wake mainly originated from the shear layer vorticity of the jet in the hole and the annular discharge stream. It soon broke down and dispersed, and further developed into the counter-rotating vortex pair in the far wake. The flow in the annular was closely dependent on R, and the sleeve's thermal protection would be evident at a higher R.