切向孔单/双排布局对离心式喷嘴锥形液膜雾化特性影响

Effects of Single-Row/Dual-Row Layout of Tangential Holes on Atomization Characteristics of Conical Sheets Emanating from Swirl Atomizer

为了研究切向孔单/双排布局对离心式喷嘴雾化性能的影响,采用高速摄影仪对两种结构喷嘴形成的锥形液膜进行了拍摄分析,测量了不同压降下液膜的破碎长度、喷雾锥角、出口轴向速度以及表面波破碎点波长等雾化性能参数,并使用这些性能参数作为初始条件,求解了锥形液膜色散方程。结果表明：双排切向孔布局使得液膜雾化性能变差,体现为相同压降下喷雾锥角减小1°~2°,破碎长度增大,增大幅度最大达8.2%;色散方程求得的破碎点波长理论值与试验值吻合较好,验证了所用液膜破碎模型的有效性;单排切向孔喷嘴形成液膜的主导扰动波增长率大于双排切向孔喷嘴的主导波增长率,从直观上解释了单排切向孔喷嘴破碎长度小于双排切向孔喷嘴的原因。

In order to investigate the effects of single-row/dual-row layout of tangential holes on atomization performance of swirl atomizer,the high-speed camera has been used to visualize and analyze the conical sheets of these two kinds of injectors. The breakup length,spray angle,exit axial velocity and the wave length of breakup point under different pressure drop have been measured. Using these parameters as initial conditions,the dispersion equation of conical sheet has been solved. The results indicate that the dual-row layout of tangential hole worsens the atomization performance,decreasing the spray cone angle about 1°~2° and increasing the breakup length up to a 8.2% amplification. The theoretical surface wave of breakup point obtained by the dispersion equation accords well with that obtained by experiment,verifying the effectiveness of breakup model used in this paper. The dominant disturbance wave growth rate of injector with single-row tangential hole is greater than that of injector with dual-row tangential hole,which explains why the breakup length of injector with single-row tangential hole is shorter than that of injector with dual-row tangential hole,intuitively.