法向过载对机载热电转换系统工质吸热过程的影响
2025,47(2):68-77
摘要：
为掌握法向过载对机载热电转换系统的影响，基于计算流体力学软件对循环工质在吸热通道内的流动换热过程进行了数值研究。结果表明，法向过载的增大改变了管道内的流场结构，从而使得壁面温度逐渐降低：沿管长方向，吸热通道的壁面温度呈现一个峰值结构，该结构的形成与近壁处流体湍流热流的变化密切相关。随着法向过载从0g增加至2g，吸热通道前端的流场从8涡结构变为双主涡结构且二次流的影响逐渐增强。双主涡结构的形成使得加热壁处的温度边界层变薄，流体的湍流热流增加，局部对流换热系数增加达80%。随着管道内换热增强，吸热通道的壁面温度逐渐降低，局部降温可达290 K
为掌握法向过载对机载热电转换系统的影响，基于计算流体力学软件对循环工质在吸热通道内的流动换热过程进行了数值研究。结果表明，法向过载的增大改变了管道内的流场结构，从而使得壁面温度逐渐降低：沿管长方向，吸热通道的壁面温度呈现一个峰值结构，该结构的形成与近壁处流体湍流热流的变化密切相关。随着法向过载从0g增加至2g，吸热通道前端的流场从8涡结构变为双主涡结构且二次流的影响逐渐增强。双主涡结构的形成使得加热壁处的温度边界层变薄，流体的湍流热流增加，局部对流换热系数增加达80%。随着管道内换热增强，吸热通道的壁面温度逐渐降低，局部降温可达290 K
基金项目：
国家部委基金资助项目（JCKY2021205B108）
国家部委基金资助项目（JCKY2021205B108）
Effect of normal overload on convective heat transfer process of working fluid in airborne thermoelectric conversion system
YANG Xuan
College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073 , China
WANG Zhongwei
College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073 , China
NIU Yaobin
College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073 , China
College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073 , China
WANG Zhongwei
College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073 , China
NIU Yaobin
College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073 , China
Abstract：
To grasp the effect of normal overload on the airborne thermoelectric conversion system, the convective heat transfer process of working fluid in heat exchange ducts was simulated on the basis of the computational fluid dynamics software. Results show that the growth of normal overload makes the flow field structure inside the pipeline changed, which finally leads to the gradually decreasing wall temperature. Along the duct, the formation of one wall temperature peak of the heat absorption channel is closely related to the change of turbulent heat flux near the heated wall. When the normal overload increases from 0g to 2g, the flow structure at the front end of the heat absorption channel changes from 8 vortexes converts to the two main vortexes structure and the influence of secondary flow is gradually increasing, the formation of the two main vortexes makes turbulent heat flux of fluid near the heated wall increases gradually due to the thinner temperature boundary layer. Hence, local heat transfer coefficient can be increased by 80%. With the enhancement of heat transfer in duct, the wall temperature of the heat absorption channel decreases and the maximum of wall temperature drop can be up to 290 K.
To grasp the effect of normal overload on the airborne thermoelectric conversion system, the convective heat transfer process of working fluid in heat exchange ducts was simulated on the basis of the computational fluid dynamics software. Results show that the growth of normal overload makes the flow field structure inside the pipeline changed, which finally leads to the gradually decreasing wall temperature. Along the duct, the formation of one wall temperature peak of the heat absorption channel is closely related to the change of turbulent heat flux near the heated wall. When the normal overload increases from 0g to 2g, the flow structure at the front end of the heat absorption channel changes from 8 vortexes converts to the two main vortexes structure and the influence of secondary flow is gradually increasing, the formation of the two main vortexes makes turbulent heat flux of fluid near the heated wall increases gradually due to the thinner temperature boundary layer. Hence, local heat transfer coefficient can be increased by 80%. With the enhancement of heat transfer in duct, the wall temperature of the heat absorption channel decreases and the maximum of wall temperature drop can be up to 290 K.
收稿日期：
2022-11-06
2022-11-06
