Influence of tubes on flow and temperature fields within water-collecting box

The water-collecting box (WCB) of conventional submarine exhaust system can prevent the reversed flow. The gas within the WCB is divided by the clapboard and a sheaf of pipes into several sections, which can get an effective heat transfer with the internal wall. After the heat transfer, the temperature of exhaust gas decreases a little. Several numerical models with different structure were established and based on which the internal flow and temperature fields were obtained. The influence of the turning style, the length and the lay of pipes on the cooling performance and resistance characteristic was analyzed. The results show that the bended pipe can reduce the exhaust resistance than the folded pipe; the L₁-larger-than-L₂ structure can reduce the exhaust resistance, enhance the cooling effect as well; the cooling effect of the L₁-equal-2L₂ model is most excellent which also makes the least resistance.