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缩放喷管加速并膨胀到超过其饱和状态时，在喷管的收缩段或喉部会发生闪蒸。闪蒸对流动的阻塞可分为三种类型.阻塞条件取决于初始压力和可压缩液体的过冷度。在等熵、均匀、平衡两相流的假设下，建立了计算喷管临界流量的流动模型。用该模型计算的质量流量与实验结果吻合较好.当流动在喷嘴喉部被阻塞时，产生压力波并向上游传播，从而调节上游流动条件。压力波在可压缩气液两相流中的传播速度依赖于含气率，并建立了两者之间的关系.超声速微喷管的性能不仅取决于马赫数，还取决于雷诺数，这取决于喷管出口处的流动条件。研究了超声速微喷管的过膨胀、正膨胀和欠膨胀范围，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。