Development of New Gas Atomizer Nozzle System for the Production of Fine Metal Powder used in Power Metallurgy

开发用于粉末冶金细金属粉末生产的新型气体雾化喷嘴系统

• 批准号: 08555048
• 负责人: MASUDA Mitsuharu
• 金额: $ 12.22万
• 依托单位: KYUSHU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08555048/
• 关键词: POWDER METALLUGY; GAS ATOMIZER; LASER DIAGNOSTICS; HOLOGRAPHY; TVD ANALYSES; 粉末治金

In the gas atomization method, the molten metal is atomized by supersonic free jets. However, the breakup process of the melted metal droplet is not known and the industrial atomizer system is designed through the empirical consideration. The aims of the present research are to clarify the breakup process with the laser-based new diagnostic method, to develop the supersonic nozzle with a special exit shape and also to establish the method for numerically predicting the detailed structure of supersonic jets. The following results are obtained.(1) To observe the breakup process of the water droplet, the novel method is developed. This uses the THG of the Nd : YAG laser (wavelength 355 nm). The inline laser holography system with this ultraviolet laser is constructed and tested with the standard particle with known diameter, and the accuracy of 10% is obtained.(2) To check the effect of the exit shape of a supersonic orifice on the breakup' of a water droplet, the orifice is made that has 50 micron-wire stretched over the diametrical direction of the orifice. It is found from the holography measurements that this wired-orifice produces water particles with the diameter 10 to 20% smaller than the normal orifice. We believe from this experiment that the droplet size is controllable by changing the exit shape of the orifice or nozzle.(3) To clarify the detailed structure of the supersonic free jets, the TVD scheme is developed for solving the Euler equations, and the jets with the ratio of stagnation to ambient pressure of up to 1500 are calculated. This scheme is extended to calculated with the boundary fitted grid to increase the accuracy. The three-dimensional calculation scheme is also developed.

在气体雾化方法中，熔融金属通过超音速自由射流雾化。然而，熔融金属液滴的破碎过程是未知的，工业雾化器系统是通过经验考虑设计的。本研究的目的是用基于激光的新诊断方法阐明破碎过程，开发具有特殊出口形状的超声速喷嘴，并建立数值预测超声速射流详细结构的方法。得到了以下结果。(1)为了观察水滴的破碎过程，发展了一种新的方法。这使用了Nd：YAG激光器的THG（波长355 nm）。利用该紫外激光器构建了同轴激光全息系统，并对已知直径的标准粒子进行了测试，获得了10%的精度。(2)为了检查超声孔的出口形状对水滴的“破碎”的影响，将孔制成具有在孔的直径方向上拉伸的50微米线。从全息测量中发现，这种线孔产生的水颗粒的直径比正常孔小10 - 20%。从这个实验中，我们相信液滴的大小是可控的，通过改变出口形状的孔或喷嘴。(3)为了研究超音速自由射流的详细结构，本文采用TVD格式求解Euler方程，并计算了滞止比为1500的超音速自由射流。为了提高计算精度，将该格式推广到边界拟合网格上进行计算.还提出了三维计算方案。

项目成果

益田光治: "紫外レーザーを用いたインラインホログラフィ法による微粒子計測" 可視化情報. 18・2. 59-66 (1998)

Mitsuharu Masuda：“使用紫外线激光的在线全息测量粒子”可视化信息 18・2（1998）。

樫谷賢士: "軸対照ノズルからの適正膨張超音速層流噴流の構造" 日本機械学会論文集 B編. 63・616. 3905-3912 (1997)

Kenji Kashitani：“来自轴对称喷嘴的适当扩展的超音速层流射流的结构”日本机械工程师学会会刊，卷 B. 3905-3912 (1997)。

HANDA,Taro: "Fine structure on shock oscillation in supersonic nozzle" Proc.4th KSME-JSME Fluids Engi.Conf.445-448 (1998)

HANDA,Taro：“超音速喷嘴冲击振动的精细结构”Proc.4th KSME-JSME Fluids Engi.Conf.445-448 (1998)

Norimatus,Y.: "Flow Visualization of Supersonic Jet from Sootblower Nzzles" Proc.Int.Conf.on Optical Tech.and Image Processing in Fluid,Thermal,and Combustion Flow. AB049. (1998)

Norimatus,Y.：“吹灰器喷嘴的超音速射流的流动可视化”Proc.Int.Conf.on 流体、热和燃烧流中的光学技术和图像处理。

井上雅弘: "レーザー蛍光法によるキャビティのある遷音速内部流れ場の温度揺らぎ測定" 可視化情報. 16・2. 83-86 (1996)

Masahiro Inoue：“使用激光荧光法测量跨声速内部流场的温度波动”可视化信息 16・2（1996）。