摘要
针对超声速气流中液体横向射流的空间振荡分布特性开展试验研究,建立射流/喷雾在纵向和三维空间内的振荡分布预测模型。试验在Ma2.1下吹式风洞中进行,采用脉冲激光背景成像方法和基于PIV原理的倾斜成像方法分别捕捉纵向和不同横截面上的喷雾瞬态分布结构,涉及的研究参数及其变化范围包括:超声速来流总压(642～1010kPa)、液体喷孔直径(0.48～2.07mm)、距离喷孔的流向距离(10～125mm)以及液气动量比(0.11～10)。通过研究,提出并定义一种用于定量描述射流/喷雾空间振荡分布的无量纲参数——喷雾分数(γ),基于喷雾分数开展了纵向喷雾振荡分布研究,建立了纵向边界带模型,并开展了模型准确性验证。研究并发现了横截面上喷雾振荡分布呈"Ω"型,提出spray body和spray foot的分区概念,构造egg-shape曲线对spray body区域的喷雾分数等值线进行拟合,建立了egg-shape曲线方程中6个关键系数的系数模型,进而建立了超声速气流中液体横向射流空间振荡分布预测模型。
The spatial oscillation distribution characteristics of liquid jet in a supersonic crossflow were studied experimentally.Two models were built for predicting the oscillation distribution in the longitudinal and three-dimensional space,respectively.The experiments were carried out in a blow-type wind tunnel with Mach number of 2.1,and various conditions were studied,including stagnation pressure of the supersonic airflow(642~1010kPa),nozzle diameters(0.48~2.07mm),distance down from nozzle(10~125mm),practical pressure ranges(0.5~4.5MPa),and jet-gas momentum flux ratio ranges(0.11~10).Pulse laser background imaging method(PLBI)was used to shoot the transient spray distribution structures from the side and PIV method was used to capture the structures in cross-sections.A key parameter(Spray Proportion,γ)was defined to quantify the spatial oscillation distribution of the spray.A longitudinal spray oscillation distribution study was carried out,a spray boundary band model was established,and the model accuracy was verified.In addition,a piecewise function of the egg-shape curve and parabola was adopted to fit the contour line to establish the model for the spatial distribution of the spray in the cross-section.Based on various cross-section distributions with multi-parameters,a mathematical model is proposed to describe the liquid spray spatial distribution.
作者
吴里银
张扣立
李晨阳
李清廉
Wu Liyin;Zhang Kouli;Li Chenyang;Li Qinglian(Hypervelocity Aerodynamics Institute of China Aerodynamics Research and Development Center,Mianyang Sichuan 621000,China;Science and Technology on Scramjet Laboratory,China Aerodynamics Research and Development Center,Mianyang Sichuan 621000,China;Science and Techno-logy on Scramjet Laboratory,National University of Defense Technology,Changsha 410073,China)
出处
《实验流体力学》
EI
CAS
CSCD
北大核心
2018年第4期20-30,共11页
Journal of Experiments in Fluid Mechanics
基金
国家自然科学基金(11802326)
