摘要
对射流垂直向下入射至主流中 ,射流管与主管直径比为 0 .1 6时 ,在宽广的射流与主流流速比下 ( R=0 .0 1～ 1 .5 ) ,测量了 3个不同区域内加装热套管前后换热系数随流速比变化的情况。通过实验发现 :热套管对于不同区域的影响情况不相同。在射流管下游区域 ,热套管对于换热系数随流速比变化情况影响很小 ,在射流管与主管相接区域以及射流管内 ,热套管有比较明显的改变传热系数的作用 ,而且对于入射流体侧面的影响要大于对于入射流体迎风侧及背风侧的影响。在流速比较高时传热系数大幅度地下降。图 6参
The local heat transfer coefficient distribution in three different areas were measured for a nozzle with thermal sleeve where jet injected vertically down to the main fow. It is a function of the velocity ratio between the jet and the main flow. Flows with velocity ratio between 0.01 and 1.5 were measured. It was found that downstream of the jet the thermal sleeve has little effect on heat transfer. At the inlet of the jet and inside the jet tube, the thermal sleeve distinctly affects heat transfer coefficient and it has more marked effect on the side of jet floe tllan that on the leeward side and upwind side. The thermal sleeve can greatly reduce heat transfer coefficient when the velocity ratio becomes larger. Figs 6 and refs 5.
出处
《动力工程》
CAS
CSCD
北大核心
2003年第4期2574-2577,共4页
Power Engineering
关键词
热套管
横向射流
流速比
传热系数
thermal sleeve: jet in crossflow: velocity ratio: heat transfer coefficient
