舰船烟囱热壁面水雾降温的大涡模拟

摘要

采用水雾喷射技术冷却舰船烟囱能够有效降低舰船红外辐射强度，对于提高舰船海上生存能力有重要意义。由于水滴蒸发和气流浮升作用相互影响，细水雾和热烟气在烟囱表面的运动是一种复杂的多相湍流流动。建立水雾在烟囱壁面空间中的蒸发和运动方程，应用多相湍流大涡模拟方法对舰船烟囱壁面空间的热烟气-水雾流动进行建模与数值仿真，分析烟囱壁面热气流浮升作用对水滴到达壁面能力和蒸发过程的影响，以及水滴直径与流量对烟囱壁面区域内热烟气下沉区域大小和流场分布参数的影响，得到水流量和水滴直径与烟囱壁面冷却温度之间的关系。研究结果对于舰船烟囱或其他热固表面冷却方案的选择和优化有一定参考价值。%The shipboard engine flue wall cooled with fine water mist is an important infrared stealth technology. The complex interactions in flue wall cooling flow make the dynamics of fine water droplet evaporation and hot gas fluid fully turbulent. The evaporation model and motion equation about the water droplet were formulated according to momentum, heat, and mass transfer. The multi-phase turbulence flow large eddy simulation method were utilized presently to investigate the characteristics of ship hot wall cooled with mist and the fluid dynamics of hot gas and floating mist. The influence of turbulence gas on the water droplet evaporation speed and movement range was investigated in much detail. The relations among the water flow rate, the average diameter of water droplets and the wall temperature drop were obtained. Simulated results can be applied in concept design and cooling effect optimization of flue wall cooled with fine water mist.