Annular mini-channel Stirling heater are replacing conventional tubular heater in modern free piston Stirling engines due to reliability and manufacturing issues. Heat transfer characteristics of a new mini channel heater with variable cross section are analyzed under oscillating flow. The effect of oscillating speed and dimensionless fluid displacement (Aₒ) on heat transfer rate is evaluated. The variation of operating speed from 150 to 1200 rpm enhanced heating power requirement from 191 to 581 W for wall temperature in 473–773 K range. However, hot space gas temperature is decreased by 66–162 K under same conditions. The change in Aₒ from 10.98 to 15.09 resulted in 13.2% enhancement in heat transfer at 300 rpm whereas maximum enhancement of 27.6% was noticed at 1200 rpm with maximum hot space temperature drop of 9.5 K. Based on the data, an empirical correlation for heat transfer in annular mini channel Stirling heater is proposed, the correlation covers kinetic Reynolds number (${\mathrm{Re}}_{\omega }$) in 0.48–1.94 range.

由于可靠性和制造问题，环形微型通道斯特林加热器替代了现代自由活塞式斯特林发动机中的常规管状加热器。在振荡流动条件下，分析了一种新型的具有可变截面的微型通道加热器的传热特性。评估了振荡速度和无因次流体排量（Aₒ）对传热速率的影响。对于473-773 K范围内的壁温，从150到1200 rpm的工作速度变化将加热功率要求从191 W增大到581W。但是，在相同条件下，热空间气体温度降低了66–162K。Aₒ从10.98更改为15.09 导致300 rpm时的传热增加13.2％，而在1200 rpm时最大热增加为27.6％，最大热空间温度下降9.5K。基于这些数据，环形迷你通道斯特林加热器的传热经验相关性为建议的相关性涵盖动力学雷诺数（${\mathrm{回覆}}_{\omega }$）在0.48-1.94范围内。