Numerical Simulation Of Ventilation Performance In Ship Engine Compartment

Air organization in cabin room has an important influence on the indoor air environmentand air quality because it directly affects the temperature, humidity, cleaning degree, cardinaltemperature, flow velocity, energy comsumpion of air conditioner and etc. It is one of themost important steps for the air conditioned and is the priority considered in engineeringdesign. Efficient ventilation and air organization are significant to improve indoor air quality,control the contamination concentration, and ensure the realization of healthy and comfortair-condition.Based on computational fluid mechanics and heat transfer theory, the thesis useFLUENT software to establish physical and mathematical model of cabin room. The theoryand method of CFD are used to simulate turbulent flow of air organization in the room. Afterthe theoretically analysis and hypothesis of physical and mathematical model, the k-εhere-equation turbulence model and method of SIMPLE are adopted to simulate thethree-dimensional air distribution of engine room. Computional results are analyzed deeplyand optimal design plan is presented finally. The main work of this paper is as follows:1. The flow distribution in engine room is fully simulated based on the same systematicresistance of fans. In the assumption of the same systematic resistance of eight fans, thenumber is given when boundary conditions set up in order to investigate the distribution ruleof velocity and temperature field. This paper simulated the engine room’s flow when thesystem resistance are1600Pa,1400Pa and1200Pa and get the flow field of three dimensionalon the above conditions.2. The flow distribution in engine room is fully simulated based on the same ventilation.With the hypothesis of unrestricted systeme resistance of eight fans, the distribution rule ofvelocity and temperature field are gained on the same ventilation through the regulation offans’ system resistances. This section simulated the engine room’s flow when the fans’ventilations are40000m3/h,30000m3/h and20000m3/h and obtained the flow field of threedimensional on the above conditions..3. The flow distribution in engine room is simulated by the changes of equipment’ssurface temperature. This paper simulated the flow in engine room on several surface temperatures and get the flow field of three dimensional on the above conditions..4. The optimal design on the ventilating characteristics of engine room is given.Through the deep analysis of the numerical simulation results, the ventilating and cooling inengine room is optimal designed for the information of ventilation improvements.