Investigation of Choking Phenomena of Supersonic Micro-nozzle Flow with Flashing Evaporation

闪蒸超音速微喷嘴流壅塞现象研究

• 批准号: 06452176
• 负责人: MATSUO Kazuyasu
• 金额: $ 5.31万
• 依托单位: KYUSHU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06452176/
• 关键词: Compressible fluid; Supersonic nozzle; Choking phenomenon; Flash evaporation; Micro-nozzle

1. When intitially subcooled high temperature and high pressure liquid is accelerated through a converging-diverging nozzle and is expanded beyond its asturation condition, flash evaporation occurs in the converging section or at the throat of the nozzle. The choking of such a flow with flash evaporation is classified into three patterns.2. The choking condition depends on the initial pressure and the subcooling of the compressible liquid. A flow model for calculating the critical massflux through the nozzle is presented assuming an isentropic, homogeneous, equilibrium two-phase flow. The mass flowrate calculated by the present model agrees well with the experimental results.3. When the flow choked at the nozzle throat, a pressure wave is generated and propagated upstream so as to adjust the upstream flow conditions. The propagation velocity of a pressure wave through a compressible gas-liquid two phase flow depends on the void fraction and the relation between them is established.4. The characteristics of supersonic micro-nozzle depends not only on the Mach number but also the Reynolds number based on the flow condition at the nozzle exit. The range of overexpansion, correct-expansion, and underexpansion of a such a nozzle is clarified, and the data of the critical flow rate through the supersonic micro-nozzle was obtained.

1.当初始过冷的高温高压液体通过收敛-扩张喷嘴加速并膨胀到超过其稳定状态时，闪蒸发生在收敛段或喷嘴的喉部。闪蒸对这种流动的堵塞可分为三种类型。堵塞条件取决于可压缩液体的初始压力和过冷度。在等熵、均匀、平衡两相流的假设下，建立了计算喷管临界质量流量的流动模型。用本模型计算的质量流量与实验结果吻合较好。当气流在喷嘴喉部堵塞时，会产生压力波并向上游传播，以调整上游的流动条件。压力波在可压缩气液两相流中的传播速度取决于含气率，并建立了它们之间的关系。超音速微喷管的特性不仅与喷管出口的马赫数有关，还与喷管出口流动条件下的雷诺数有关。明确了超声速微喷管的过膨胀、正膨胀和欠膨胀的范围，得到了超声速微喷管的临界流量数据。

项目成果

Kazuyasu Mastuo, et al.: "Critical Flow Rate of Flashing Subcooled Water through a Converging Nozzle" Engineering Sciences Reports, Kyushu University. 18-1. 11-18 (1996)

Kazuyasu Mastuo 等人：“通过收敛喷嘴的闪蒸过冷水的临界流量”工程科学报告，九州大学。

片野田洋: "不足膨張軸対称超音速噴流の数値計算" 日本機械学会論文集. 61・589. 3236-3242 (1995)

Hiroshi Katanoda：“欠膨胀轴对称超音速射流的数值计算”日本机械工程师学会会刊 61・589 3236-3242（1995）。

宮里義昭: "超音速ノズルにおける過膨張流れの特性" 可視化情報. 15. 23-26 (1995)

Yoshiaki Miyazato：“超音速喷嘴中过度膨胀流的特性”可视化信息。15. 23-26 (1995)

Yoshiaki Miyazato, et al.: "Characteristics of Overexpanded Flow in a Supersonic Nozzle" Journal of Visualization Society of Japan. 15-2. 23-26 (1995)

Yoshiaki Miyazato 等人：“超音速喷嘴中过膨胀流动的特性”日本可视化学会杂志。

Hiroshi Katanoda, et al.: "Numerical Calculation of Underexpanded Axisymmetric Supersonic Jet" Transaction of Japan Society of Mechanical Engineers. 61-589. 3236-3242 (1995)

Hiroshi Katanoda 等人：“欠膨胀轴对称超音速射流的数值计算”日本机械工程师学会会刊。