气泡雾化喷嘴液雾特性

Studies on spray characteristics of barbotaged atomizer

关键词:  气泡  雾化  液雾特性+  超音速燃烧  二相流

Key words:  Air bubble  Atomization  Spray characteristics~+  Supersonic combustion  Two phase flow

摘要:

为了研究静止空气中气泡雾化喷嘴的液雾特性,利用粒子多普勒分析仪(PDA)和Mie散射显示法,对气泡雾化喷嘴在水压2 5MPa和3 4MPa条件下,较宽气液比范围内的液雾的张角、粒度及速度分布进行了测量,分析了水压、气液比、两股射流相互作用对液雾的影响。结果表明,气泡对液体射流的雾化具有较大的增强作用,同时发现存在一临界气液比(介于3%～4%之间),当气液比达到临界值后,射流的雾化突然增强,且运行稳定。

Abstract:

The spray characteristics of barbotaged atomization in quiescent atmosphere by using Particle Dynamics Analyzer (PDA) and Mie-Scattering were experimentally investigated. The experiments were conducted in a wider gas/liquid mass ratio (GLR) and the water injection pressure 2.5MPa and 3.4MPa respectively. The major parameters of spray including velocity, drop size and initial expansion angle were measured and their dependence on injection pressure, GLR and interaction of two sprays were analyzed. Results show that the drop size decreases and the initial expansion angle of the spray increases significantly with barbotaged atomization. It was found that there existed a critical GLR value around 3%～4%, and the spray being enhanced abruptly and performed steady after the critical value reached.