The horseshoe vortex generated around the sail-body junction of submarine has an important influence on the non-uniformity of submarine wake at propeller disc. The flow characteristics in the horseshoe vortex generate...The horseshoe vortex generated around the sail-body junction of submarine has an important influence on the non-uniformity of submarine wake at propeller disc. The flow characteristics in the horseshoe vortex generated area are analyzed, and a new method of vortex control baffler is presented. The influence of vortex control baffler on the flow field around submarine main body with sail is numerically simulated. The wind tunnel experiment on submarine model is carried out, and it is proved that the vortex control baffler can weaken the hoi-seshoe vortex and decrease the non-uniformity of the wake at propeller disc. It is shown from the experiment results that the effect of vortex control baffler depends on its installation position; with a proper installation position, the non-uniform coefficient of submarine wake would be declined by about 50%; the Reynolds number of submarine model has an influence on the effect of vortex control baffler too, and the higher the Reynolds number is, the better the effect of the vortex control baffler is.展开更多
为了提高氧化沟内水流的混掺能力,降低系统的运行能耗,对卡鲁塞尔(Carrousel)氧化沟的结构进行优化研究。采用数值计算方法求解气液两相流时均方程,辅以RNGk-ε紊流模型封闭时均方程组,自由面的追踪采用VOF(volume of fluid)方法处理,...为了提高氧化沟内水流的混掺能力,降低系统的运行能耗,对卡鲁塞尔(Carrousel)氧化沟的结构进行优化研究。采用数值计算方法求解气液两相流时均方程,辅以RNGk-ε紊流模型封闭时均方程组,自由面的追踪采用VOF(volume of fluid)方法处理,对六沟道试验氧化沟在曝气推流设备后增设导流板与无导流板2种工况下的水力特性进行研究。通过对比2种工况下的流速分布规律,得出在曝气转盘下游加装导流板时,不会导致氧化沟中上部污泥滞留,并能增大氧化沟底部水流速度,改善沟内垂线上的流速分布。在曝气推流设备后增设导流板来改善水力特性有利于消除氧化沟池底积泥现象,延长水气混掺时间,提高水处理效率。展开更多
基金supported by the State Key Laboratory of Ocean Engineering,Shanghai Jiao Tong University(Grant No.0708)
文摘The horseshoe vortex generated around the sail-body junction of submarine has an important influence on the non-uniformity of submarine wake at propeller disc. The flow characteristics in the horseshoe vortex generated area are analyzed, and a new method of vortex control baffler is presented. The influence of vortex control baffler on the flow field around submarine main body with sail is numerically simulated. The wind tunnel experiment on submarine model is carried out, and it is proved that the vortex control baffler can weaken the hoi-seshoe vortex and decrease the non-uniformity of the wake at propeller disc. It is shown from the experiment results that the effect of vortex control baffler depends on its installation position; with a proper installation position, the non-uniform coefficient of submarine wake would be declined by about 50%; the Reynolds number of submarine model has an influence on the effect of vortex control baffler too, and the higher the Reynolds number is, the better the effect of the vortex control baffler is.
文摘为了提高氧化沟内水流的混掺能力,降低系统的运行能耗,对卡鲁塞尔(Carrousel)氧化沟的结构进行优化研究。采用数值计算方法求解气液两相流时均方程,辅以RNGk-ε紊流模型封闭时均方程组,自由面的追踪采用VOF(volume of fluid)方法处理,对六沟道试验氧化沟在曝气推流设备后增设导流板与无导流板2种工况下的水力特性进行研究。通过对比2种工况下的流速分布规律,得出在曝气转盘下游加装导流板时,不会导致氧化沟中上部污泥滞留,并能增大氧化沟底部水流速度,改善沟内垂线上的流速分布。在曝气推流设备后增设导流板来改善水力特性有利于消除氧化沟池底积泥现象,延长水气混掺时间,提高水处理效率。