The multi-nozzle spray cooling with liquid nitrogen can achieve high heat transfer rate and uniform temperature for a large-scale environmental simulation system. The understanding of the flow characteristics is crucial to the accurate control of the mass flow rates and the temperature distribution in a cryogenic system. This article combines the experimental and numerical approach to reveal the external and internal flow characteristics of the multi-nozzle spray with liquid nitrogen. It is found that a higher injection pressure is followed by an increasing mass flow rate under a given nozzle combination. The number and position of the low-temperature region in the downstream field correspond to the number and the arrangement of spraying nozzles under each combination. The pressure differences have little effect on the spray cone angle of a single-nozzle. The flow swirl is induced by the slotted swirl in the nozzle chamber and the cavitation is caused by the abrupt change structure at the orifice. In the absence of the friction and the resistance, the ratio of the mass flow rate in the multi-nozzles to that in the single-nozzle is basically equal to the ratio of the nozzle numbers. And the nearly equal amount of liquid nitrogen flows into each single nozzle of a multi-nozzle array under the varied injection pressure and inlet temperature conditions. The experimental research and the theoretical analysis are to provide insights on the practical engineering application of the multi-nozzle spray cooling in a cryogenic environmental simulation system.

液氮的多喷嘴喷雾冷却可以为大型环境模拟系统实现较高的传热速率和均匀的温度。对流动特性的理解对于精确控制低温系统中的质量流量和温度分布至关重要。本文结合了实验和数值方法，揭示了液氮多喷嘴喷雾的内部和外部流动特性。已经发现，在给定的喷嘴组合下，较高的注射压力之后是质量流量的增加。下游区域中的低温区域的数量和位置对应于每种组合下的喷嘴的数量和布置。压力差对单喷嘴的喷雾锥角影响很小。流动涡流是由喷嘴腔中的狭缝涡流引起的，而气穴现象是由孔口处的突变结构引起的。在没有摩擦和阻力的情况下，多喷嘴的质量流率与单喷嘴的质量流率之比基本上等于喷嘴数的比。在变化的喷射压力和入口温度条件下，几乎等量的液氮流入多喷嘴阵列的每个单个喷嘴。实验研究和理论分析将为在低温环境模拟系统中多喷嘴喷雾冷却的实际工程应用提供见识。流动涡流是由喷嘴腔中的狭缝涡流引起的，而气穴现象是由孔口处的突变结构引起的。在没有摩擦和阻力的情况下，多喷嘴的质量流率与单喷嘴的质量流率之比基本上等于喷嘴数的比。在变化的喷射压力和入口温度条件下，几乎等量的液氮流入多喷嘴阵列的每个单个喷嘴。实验研究和理论分析将为在低温环境模拟系统中多喷嘴喷雾冷却的实际工程应用提供见识。流动涡流是由喷嘴腔中的狭缝涡流引起的，而气穴现象是由孔口处的突变结构引起的。在没有摩擦和阻力的情况下，多喷嘴的质量流率与单喷嘴的质量流率之比基本上等于喷嘴数的比。在变化的喷射压力和入口温度条件下，几乎等量的液氮流入多喷嘴阵列的每个单个喷嘴。实验研究和理论分析将为在低温环境模拟系统中多喷嘴喷雾冷却的实际工程应用提供见识。多喷嘴中的质量流率与单喷嘴中的质量流率之比基本上等于喷嘴数的比。在变化的喷射压力和入口温度条件下，几乎等量的液氮流入多喷嘴阵列的每个单个喷嘴。实验研究和理论分析将为在低温环境模拟系统中多喷嘴喷雾冷却的实际工程应用提供见识。多喷嘴中的质量流率与单喷嘴中的质量流率之比基本上等于喷嘴数的比。在变化的喷射压力和入口温度条件下，几乎等量的液氮流入多喷嘴阵列的每个单个喷嘴。实验研究和理论分析将为在低温环境模拟系统中多喷嘴喷雾冷却的实际工程应用提供见识。