Abstract: Heat transfer and fluid flow performance in internally finned tube with blocked coretube was numerically investigated with the realizable k-ε turbulence model and wall function methodThe working fluid was airThe numerical method was validated by comparing the calculated results with available experimental dataIt was found that there existed an optimal value for the ratio of coretube outside diameter to outertube inside diameter, and this optimal value decreased with the increase of air flow rateThe optimal ratio was about 0.5—0.625 in the range of studied parametersMeanwhile under the condition of identical pressure, the optimal ratio was also about 0.44—0.56The conclusion is useful for the design of this kind of internally finned tubes.

摘要： 采用可实现的k-ε湍流模型和壁面函数法对带不同直径堵塞芯管的内翅片管内空气的湍流流动和换热特性进行了数值模拟，利用试验数据检验了计算方法的正确性。在对不同流量下改变芯管直径进行数值模拟的结果表明：在一定流量下，芯管外径与外管内径之比存在着一个最佳值，使单位压降、单位翅片面积下的换热量最大，而且随着流量的增加，最佳芯管外径与外管内径之比呈减小趋势。在本文所研究的参数范围内，这一最佳比值在0.5-0.625之间。同时也对在相同压降条件下进行了数值计算，结果表明，当芯管外径与外管内径最佳比值为0.4-0.56左右时，单位翅片面积下的流量和换热量之积达最大值。这一结论为内翅片管的优化设计提供了重要依据。