Elucidation of the gas flow and droplet behavior near the liquid sheet at the nozzle exit of the hollow-cone spray

阐明空心锥形喷雾喷嘴出口处液层附近的气流和液滴行为

• 批准号: 05650196
• 负责人: TAKAGI Toshimi
• 金额: $ 1.41万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05650196/
• 关键词: Hollow-cone Spray; Phase-Doppler Technique; Laser Sheet; Numerical Simulation; Liquid Sheet Behavior; Droplet Behavior; 位相ドップラ法; 渦巻き噴射弁; ガス流動; 液膜形状; 表面張力; 数値シミュレーション

Behavior of droplets and the air flow in a hollow-cone spray was studied paying atteintion to the hollow-cone liquid sheet formed at the atomizer orifice. The shape of the liqiud sheet was investigated by taking photographs with a flush of Nd-YAG pulse laser. Phase Doppler method was used to detect the behavior of the droplets adjacent to the break-up point of the liquid sheet. Numerical simulation was carried out to compare the experiments to the predictions. The results obtained are as follows.(1) The cone angle of the liquid sheet formed at the atomizer orifice tends to converge or decrease along with the flow. The instantaneous angle is less than that of the observed time-averaged envelop of the liquid sheet. The direction of the liquid sheet flow at the break-up point dominates the initial droplet velocity and its direction. The shape is related to the surface tension of the liquid sheet.(2) The break-up point of the liquid sheet fluctuates up and down and the initial droplet velocity and the direction fluctuates significantly.(3) Numerical simulation incorporating the existence of the liquid sheet reveals that the the movement of the liquid sheet induces strong air stream and that this air stream selectively transports small droplets and plays an essintial role in classification of droplets by size and dispersion of droplets.

针对雾化喷嘴孔口形成的中空锥形液膜，研究了中空锥形喷雾中液滴和气流的行为。用脉冲激光对液膜进行拍照，观察液膜的形状。用相位多普勒法检测液膜破碎点附近液滴的行为。进行了数值模拟，将实验结果与预测结果进行了比较。结果表明：(1)雾化孔处形成的液膜锥角随流量增大而趋于收敛或减小。瞬时夹角小于观测到的液膜时间平均包络的夹角。破碎点处液膜的流动方向决定了液滴的初始速度及其方向。液膜的形状与液膜的表面张力有关。(2)液膜的破碎点起伏不定，液滴的初始速度和方向波动很大。(3)考虑液膜的存在，数值模拟表明液膜的运动诱导了强烈的气流，这种气流选择性地输送小液滴，并对液滴的大小和分散程度进行分类。

项目成果

中野 祥: "非定常噴霧火炎のパラメトリック解析" 第32回燃焼シンポジウム. 346-348 (1994)

Sho Nakano：“不稳定喷雾火焰的参数分析”第 32 届燃烧研讨会 346-348 (1994)。

Okamoto Tatsuyuki: "Mesurements of Droplets Begaviour Using Phase-Doppler Technique and Studies on Structure of Spray Flow Fields" Bulletin of the JSME,B. 59. 349-354 (1993)

冈本达幸：《使用相位多普勒技术测量液滴行为及喷雾流场结构的研究》JSME通报，B。

岡本達幸: "位相ドップラー法を用いた滴挙動の計測と噴霧流の構造に関する研究" 日本機械学会論文集B編. 59. 349-354 (1993)

Tatsuyuki Okamoto：“使用相位多普勒方法测量液滴行为和喷雾流结构的研究”日本机械工程师学会会刊，B 版 59. 349-354 (1993)。

Takagi Toshimi: "Numerical Simulation of Mixing and Combustion in Transient Spray" Int.Symposium of COMODIA 94. 397-402 (1994)

Takagi Toshimi：“瞬态喷雾中混合和燃烧的数值模拟”Int.Symposium of COMODIA 94. 397-402 (1994)

Okamoto, Tatsuyuki: "Studies on the Behavior of Droplets and the Air Flow in the Spray (Hollow-cone Spray)" Bulletin of the JSME,B. 60. 367-374 (1994)

冈本龙之：“喷雾（空心圆锥喷雾）中液滴行为和气流的研究”JSME 通报，B。