This paper designed a platelet heat exchanger in the solar thermal thruster and analyzed the unsteady-state conjugate heat transfer characteristics between heat exchanger and propellant. The conjugate heat transfer (CHT) computational fluid dynamics (CFD) simulation of the 3D model of the platelet under steady-state conditions was carried out with different mass flow rates to find the empirical correlation between the average Nusselt number and the average Reynolds number. The unsteady-state 1D simplified model of the heat exchanger was established using a loose coupling algorithm based on quasi-steady flow domain and finally verified by experiments. The results show that the platelet structure could heat the working medium to more than 2380 K with the heat transfer efficiency of 87% and produce a peak thrust of 0.57 N and specific impulse of 2200 m/s; in steady state, the outlet temperature and heat transfer efficiency of the heat exchanger were stable at 1950 K and 69%. Moreover, 1D model could accurately reflect the real heat exchange situation to a certain extent, the simulation error was less than 5% compared with the 3D model, and the calculation time was greatly shortened, making it more convenient to adjust the heat exchange strategy. The experimental results were consistent with the simulation results at the initial stage of heat exchange, and the difference was mainly reflected in the steady-state stage, which might be caused by the lack of precision of the experimental equipment.

中文翻译：

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太阳能热推进器换热结构设计及推进性能研究

本文设计了太阳能热推进器中的片状换热器，并分析了换热器与推进剂之间的非稳态共轭传热特性。采用不同的质量流量对稳态条件下的血小板 3D 模型进行共轭传热 (CHT) 计算流体动力学 (CFD) 模拟，以找到平均努塞尔数和平均雷诺数之间的经验相关性。采用基于准稳态流域的松耦合算法建立了换热器的非稳态一维简化模型，并最终通过实验验证。结果表明，片状结构可以将工质加热到2380 K以上，传热效率为87%，峰值推力为0。57 N 和 2200 m/s 的比冲；稳态下，换热器出口温度和传热效率稳定在1950 K和69%。而且一维模型在一定程度上可以准确反映真实的换热情况，与3D模型相比，仿真误差小于5%，计算时间大大缩短，换热策略调整更加方便。实验结果与热交换初期的模拟结果一致，差异主要体现在稳态阶段，这可能是由于实验设备精度不足造成的。一维模型能够在一定程度上准确反映真实的换热情况，与3D模型相比，仿真误差小于5%，计算时间大大缩短，换热策略调整更加方便。实验结果与热交换初期的模拟结果一致，差异主要体现在稳态阶段，这可能是由于实验设备精度不足造成的。一维模型能够在一定程度上准确反映真实的换热情况，与3D模型相比，仿真误差小于5%，计算时间大大缩短，换热策略调整更加方便。实验结果与热交换初期的模拟结果一致，差异主要体现在稳态阶段，这可能是由于实验设备精度不足造成的。