内环肋管道中湍流流动与换热的数值模拟

Numerical simulation of turbulence flow and heat transfer characteristics in the tube with circumferential fins

采用K-ε模型和壁面函数法对内环肋管道的湍流流动和换热进行了数值模拟.全面分析了流动特性对换热的影响,包括阻力因子和换热系数随雷诺数、肋高比和肋距比的变化关系.结果表明,努谢尔特数随雷诺数的增大近似线性增大,在肋高与管径之比为0 04～0 12,Re=20000～70000内,肋间距与管径之比为8时,阻力系数与努谢尔特数将达到最大.从而得到确定内环肋管道换热规律的重要依据.

Using K-Ε equation and wall function, the turbulent flow and heat transfer in the tube with circumferential are numerically simulated. The influence of flow properties on heat transfer, including the relations of friction factor and heat transfer coefficient with fin size, fin spacing and Reynolds number is analyzed. The result shows that with the increase of Reynolds number, Nusselt number closes to linearity approximately. When the range of H/D is between 0.04-0.12 and Re number range is from 20000 to 70000, the friction factor and Nusselt number will reach the peak at the point that P/H equal to 8. The relations are an important foundation to confirm the rules of heat transfer in the tube with circumferential.