格芯夹层结构散热性能的数值计算评估

为评估格芯夹层结构的传热性能以及代替传统的板式肋片结构应用于汽车散热系统中的可能性，文章对几种典型的格芯夹层结构（如kagome lattice，tetrahedral lattice和pyramidal lattice）和板式肋片（corrugated plate）结构实施了一系列的三维数值计算评估.通过对比相同Reynolds数下的传热系数和相同泵功率下的局部Nusselt数来评估各组结构的传热性能.结果显示，相同Reynolds数条件下，各组格芯夹层结构的传热系数较板式肋片结构均有提高，同时摩擦阻力也大幅度增大.在相同泵功率条件下，由于板式肋片结构所受形阻基本可以忽略，因此在较低泵功率范围内（< 1 500 W），板式肋片的局部Nusselt数最大.随着泵功率的增长，当泵功率提高到3 000 W，tetrahedral的Nusselt数与板式肋片持平并进一步增大，显示出了格芯夹层结构的应用潜力.高传热性能而低摩擦阻力的格芯夹层结构完全有潜力代替传统的板式肋片结构应用于新型高效紧凑的散热系统中. 

Numerical Estimation of Heat Transfer Performance of Lattice Core Sandwich Structure

In order to evaluate the heat transfer performance of lattice core sandwich structure as well as the possibility of application of that, instead of conventional plate fin structure, within heat exchange system of electric vehicle, in this paper, a series of three-dimensional numerical calculations have been conducted for several typical lattice core sandwich structures, such as kagome lattice structure, tetrahedral lattice structure, pyramidal lattice structure, corrugated plate as well in reference, in terms of their heat transfer performance. For this purpose, the heat transfer coefficients under equal Reynolds number and the Nusselt numbers under equal pumping power were compared. As a result, compared with the corrugated plate, the heat transfer coefficients of these lattice core sandwich structures increase, however, the friction factors of that also achieve a great increase. On the other hand, under the condition of same pumping power, the corrugated plate structure achieves the largest Nusselt number at a lower range of pumping power (< 1 500) because of its almost negligible friction factor. With the increase of pumping power, such as 3 000 W, the Nusselt number of tetrahedral lattice structure gets close to that of corrugated plate and maintains further increasing. This shows its great potential of application within heat exchanger system. A novel structure, which has higher heat transfer performance and lower friction factor, is expected to be used within new type compact heat exchanger system replacing conventional plate fin structure.