Experimental Evaluation of Low Pressure-Swirl Atomizer Applied Engineering Design Procedure

摘要

In a pressure-swirl atomizer a swirling motion is imparted to the fuel leading it, under the action of centrifugalnforces, to spread out in the shape of a hollow cone as soon as it leaves the exit orifice. This kind of atomizer is used inngas turbines and liquid-propellant rockets. The need tominimize the combustor length usually leads to spray anglesnaround 90 deg. The present work presents a procedure to design and verify the experimental behavior for lownpressure-swirl atomizers. This atomization condition is especially important, for example, in the case of gas turbinenoperation under idle regime. The Sauter mean diameter and the spray-cone angle are evaluated and made to fit thencalculated atomizer dimensions. The Sauter mean diameter is obtained through the use of a model originallyndeveloped for fan-spray atomizers and extended for pressure-swirl atomizers. A pressure-swirl atomizer wasnmanufactured following this design procedure. The discharge coefficient, the spray-cone angle, and the Sautermeanndiameterwere evaluated experimentally and comparedwith the theory used to design the atomizer displaying a goodnmatching. The spray Sauter mean diameter was measured with a laser scattering system.