风冷式换热器的热性能直接影响许多暖通空调设备的能效。这些风冷式热交换器的基本特性是固体-空气界面边界层的热阻。为了改善空气侧的传热，通常会采用被动对流强化技术，但这些技术会导致压降增加和污垢敏感性增加。Koplow（2010）发明的空气轴承热交换器（ABHE）绕过了传统热交换器拓扑结构的一些固有物理模拟，并随后展示了前所未有的空气侧热性能，尤其是在非自愿限制的应用中。本研究中所述的ABHE包括一个直径为10厘米[3.9英寸]的固定基板和一个旋转叶轮，叶轮由一个直径为10微米[0.39·10-3英寸]的流体动力（i。 e、 自我维持的）空气轴承。热负荷作用于基板底部，流经空气轴承进入旋转叶轮。叶轮具有远离底板的翅片，其形状可作为离心式风扇叶片，引导周围环境空气轴向进入和径向排出。在此过程中，空气吸收来自基板的上述热负荷。ABHE的一个关键概念是，热翅片表面位于一个旋转坐标系中，该坐标系对翅片上边界层中的流体粒子施加无离心力。这个额外的物体力会使边界层保持非常薄，从而提高传热系数。在这项工作中，我们给出了数值模拟结果和实验测量，以证明两种不同的10厘米[3.9英寸]直径ABHE设计的性能。 我们使用ANSYS CFX预测了自由输送点的流动和传热特性，并通过几项实验验证了这些模拟结果:（1）在定制的流动台上测量了几种转速下的风扇曲线，以及（2）在自由输送点测量了几种转速下的传热系数。这些结果证实，ABHE的性能水平超过了最先进的水平；例如，一种设计的空气侧一次对流换热系数在4500 rpm时为2000 W/m2·K[350 Btu/h·ft2·°F]。此外，我们观察到，其泵送性能超过了同等直径的轴流风机（例如，在3750 rpm时，其具有150 Pa[0.60 inH2O]的关闭压力和2370 L/min[83.7 ft3/min]的自由输送流量）。引用:ASHRAE论文CD:2014 ASHRAE冬季会议，纽约

The thermal performance of air-cooled heat exchangers has a direct impact on the energy efficiency of many HVAC&R devices. The fundamentallimitation of these air-cooled heat exchangers is the thermal resistance of the boundary layer at the solid-air interface. To improve the air side heattransfer, passive convective enhancement techniques are often employed, but these result in undesirable increases in pressure drop and highersusceptibility to fouling. The air bearing heat exchanger (ABHE), invented by Koplow (2010), circumvents some of the inherent physicallimitations of conventional heat exchanger topologies and has subsequently demonstrated unprecedented air-side thermal performance, especially involume-constrained applications.The ABHE described in this study comprises a 10 cm [3.9 in] diameter stationary baseplate and a rotating impeller separated by a c.10 μm[0.39·10-3 in] hydrodynamic (i.e. self-sustained) air bearing. A thermal load is applied to the bottom of the baseplate and flows across the airbearing and into the rotating impeller. The impeller has fins that extend away from the baseplate and are shaped to act as centrifugal fan blades,inducing the surrounding ambient air to enter axially and exit radially. During this process the air absorbs the aforementioned thermal loadoriginating from the baseplate. A key concept of the ABHE is that the hot fin surfaces reside in a rotating reference frame, which imposes acentrifugal body force on fluid particles in the boundary layer on the fins. This additional body force causes the boundary layer to remain very thinand results in an enhanced heat transfer coefficient.In this work, we present numerical simulation results and experimental measurements to demonstrate the performance of two different 10 cm [3.9in] diameter ABHE designs. We used ANSYS CFX to predict the flow and heat transfer characteristics at the free delivery point, and wevalidated these simulation results with several experiments: we (1) measured fan curves at several rotational speeds on a custom-made flow bench,and (2) measured the heat transfer coefficient at several rotational speeds at the free delivery point.These results confirm that the ABHE is capable of levels of performance beyond the state-of-the-art; for example, one design was measured to havean air side primary convective heat transfer coefficient of 2000 W/m2·K [350 Btu/h·ft2·°F] at 4500 rpm. In addition, we observed that itspumping performance surpassed axial fans of comparable diameter (e.g. at 3750 rpm, it had a 150 Pa [0.60 inH2O] shut-off pressure and a2370 L/min [83.7 ft3/min] free delivery flow rate).