Experimental investigations on atomization characteristics of dual-orifice atomizers part I: Optimization method formation

Abstract

In this paper, influences of structure parameters on mass flow and atomization characteristics (spray cone angle, SMD, liquid film fusion and separation) of dual-orifice atomizers were investigated using Fraunhofer diffraction optical instrument and high-speed shadowgraph technique. The main influential structure parameters are obtained by structural parameter sensitivity analysis. Liquid film fusion and separation is an important atomization characteristic lacking of in-depth research. Results of liquid film fusion and separation illustrate that three patterns (separation-fusion-secondary separation) of main stage liquid film and pilot stage liquid film appear with the increase of Δ P. Liquid film fusion makes SMD larger, and there is a delay in liquid film separation when reduce Δ P after liquid film fusion. In addition, mass flow and spray cone angle are key factors which affect liquid film fusion pressure, liquid film secondary separation pressure and distance between two liquid films. The smaller the pilot stage mass flow is, the larger the effect of the main stage on pilot stage spray cone angle will be. Results in this paper could be used to the design and optimization of new dual-orifice atomizers.

An Improved Shape from Focus Method for Measurement of Three-Dimensional Features of Fuel Nozzles

“…The geometrical characteristics of the dual-orifice pressure-swirl nozzle significantly affect the flow performance [ 1 , 2 ]. These geometrical characteristics are mainly cones and swirl slots.…”

“…Fuel nozzles are important for aero-engines, and their dimensional accuracy determines the spray and atomization characteristics, thus affecting the performance of the whole aero-engine. The geometrical features, such as the cone and swirl slot of the nozzle, significantly affect the atomization characteristics [ 1 , 2 , 3 , 4 ]. As those geometrical features usually consist of small curved surfaces and require high manufacturing precision, two-dimensional measurement techniques are not applicable to them and three-dimensional (3D) measurement methods are therefore required.…”

Experimental investigations on atomization characteristics of dual-orifice atomizers part II: Optimization method application

“…Authors had studied influences of structure parameters on mass flow and atomization characteristics (spray cone angle, SMD , liquid film fusion and separation) of dual-orifice atomizers. 1 Results illustrated that main stage mass flow was sensitive to main nozzle diameter, main convergent angle, main swirling groove depth and main swirling angle. Main stage spray cone angle was sensitive to main nozzle diameter and main nozzle shape.…”

“…In addition, there are some differences between the new dual-orifice atomizer and dual-orifice atomizer used in Part I. 1 For example, the mass flow is much smaller, there is an expansion angle at pilot nozzle to regulate pilot stage spray cone angle, and there is no recess length between main nozzle and pilot nozzle. In a word, this paper is not only the application of the previous optimization method, but also further improvement.…”

Effect of orifice size on liquid breakup dynamics and spray characteristics in slinger atomizers

“…The main advantages of the slingers are the requirement of much lower liquid injection pressure and simple design compared to the swirl injectors and air-blast injectors employed in typical aero-engines. [4][5][6] In addition, it ensures very good atomization quality for a wide range of operating conditions, and also fuel flexibility. 7,8 In general, the rotary atomizers can be (a) flat disc, (b) plane cup, and (c) perforated cups types, 9 among which the perforated cup type are usually adopted in slinger atomizers.…”