柴油机排气喷水过程仿真及红外预测

Simulation on diesel engine exhaust by spraying water and infrared prediction

为降低舰船柴油机排气系统的红外辐射强度,往往通过加装喷水降温装置降低其排气系统温度。本文基于喷水降温装置的试验数据,通过Ansys Fluent软件建立起喷水降温装置工作前后的流场和温度场,仿真温度和总压计算结果的误差为1.3%和0.5%,验证了喷水降温装置仿真的真实性和可靠性。根据仿真结果对排气出口在3~5μm的红外辐射亮度进行计算,结果表明使用喷水降温装置出口红外辐射亮度可降低98%,能大幅提升舰船的红外隐身性能。

The installation of water spray refrigerated device can often drop the temperature of its exhaust system,which will simultaneously reduce the infrared intensity of the ship’s exhaust system.With the assistance of testing results of the water spray refrigerated device,the flow field and temperature field of the water spray refrigerated device before and after the operation are established by ANSYS fluent.It can control the error range of temperature and total pressure between calculation and testing result being 1.3%and 0.5%,which confirmed the authenticity and reliability of the simulation of the water spray refrigerated device.According to the calculated results,the infrared radiance of the exhaust outlet 3~5μm was calculated and confirms that the infrared radiance of exhaust gas will be reduced by about 98%via the use of water spray refrigerated device.The device can improve the infrared concealment of ships a lot.