舰船发动机排气管内顺流喷雾降温的CFD分析  

CFD Simulation of Water Spray Downstream in Gas Cooling of Marine Engine

作　　者：袁江涛[1] 金仁喜[2] 杨立[1] 张健[1] 

机构地区：[1]海军工程大学船舶与动力学院,武汉430033 [2]海军潜艇学院,青岛266071

出　　处：《武汉理工大学学报（交通科学与工程版）》2009年第2期314-317,共4页Journal of Wuhan University of Technology（Transportation Science & Engineering）

基　　金：国家部委资助项目(批准号:101050202)

摘　　要：发动机排气管废气出口温度过高是影响舰船红外隐身性能的重要因素之一.在排气管内喷雾能有效降低废气出口温度.针对排气管内顺流喷雾时的气液两相湍流流动与热质传递,用Euler-Lagrange方法建立了数理计算模型,用CFD计算软件进行了数值模拟.考察了水雾出口温度、水流量、水雾喷射夹角及雾滴初始粒径对喷雾降温效果的影响.结果表明:排气管内顺流喷雾时,废气出口温度大幅降低,呈倒钟形分布;废气出口温度的大小和分布与水流量、水雾喷射夹角及雾滴初始粒径息息相关;水流量越大、雾滴初始粒径越小,则废气出口温度越低,废气出口温度与水流量的大小基本呈线性关系;雾滴初始粒径越小、水雾喷射夹角越大,则废气出口温度分布越均匀;而废气出口温度的大小与分布对水雾出口温度的变化并不敏感.The temperature of the exhaust gas in diesel engine is high, which is one of the dominating contributors to the infrared stealth of ships. The high temperature exhaust gas can be cooled using a spray of water fog. For the gas-liquid two phase turbulent flow and the heat and mass transfer during the water spraying downstream into the exhaust pipe, the mathematical physics model was presented using the Euler-Lagrange method, and the numerical simulation was performed using CFD software. The influences of the water fog initial temperature, the water flow rate, the water spray angle and the water droplets initial size on the drop degree of the gas temperature were investigated. Results indicate that the profile of the gas outlet temperature appears to be an inverted bell shape which dropped evidently when the water spray is introduced. The gas outlet temperature is closely linked with the water flow rate, the water spray angle and the water droplets initial size. The gas outlet temperature drops with increasing the water flow rate and decreasing the water droplets initial size, and the relationship between the gas outlet temperature and the water flow rate is nearly linear. The smaller the water droplets initial size is and the bigger the water spray angle is, the more homogeneously the gas outlet temperature distributes. The gas outlet temperature is insensitive to the change of the water fog initial temperature.

关 键 词：发动机 废气 传热传质 多相流 计算流体动力学 

分 类 号：U664.1[交通运输工程—船舶及航道工程] TK414[交通运输工程—船舶与海洋工程]