对叶片倾角在30°~60°之间的7种开槽螺旋叶片转子的湍流流动与传热特性进行了数值模拟研究。数值模拟采用RNG湍流模型,采用SIMPLE算法进行速度和压力的耦合,对管内壁面采用强化壁面处理法。选取管程入口流量为2.6 m3/h时管程中部截面的速度场、温度场和湍流强度进行了分析,结果表明,开槽螺旋叶片转子可在换热管内引起旋流,增强管内流体湍动,促进对流传热。考虑转子引起传热和阻力两方面因素,采用综合评价指标PEC对7种不同倾角转子进行比较,叶片倾角为60°的开槽螺旋叶片转子具有较好的综合传热性能。
The turbulent flow and heat transfer characteristics in tubes with grooved helical lobe rotors of different dip angles were numerically studied.The simulation was based on the RNG turbulence model.SIMPLE algorithm was employed for the coupling between velocity and pressure,and the enhanced wall treatment was applied on the flow and heat transfer of the inner wall of tube side.The velocity field,temperature field and turbulence intensity of tube side were analyzed at a volume flow rate of 2.6m3/h in tube side inlet.Results indicated that the grooved helical lobe rotor could induce a swirling flow,and enhance the tube side convective heat transfer.Considering both heat transfer rate and friction factor,the performance evaluation criteria(PEC) of rotors with different dip angles were compared,rotor with dip angle of 60° had the best thermal performance characteristic.