Penetration and Break-Up Studies of Discrete Liquid Jets in Cross Flowing Airstreams

Abstract

Penetration and breakup characteristics of a discrete liquid jet injected into a high-velocity cross flowing airstream were investigated as a basis of plain-jet airblast atomizer design. The main variables covered in this phase were, airstream velocity (from about 35 to 150 m/s), liquid jet velocity (from about 5 to 25 m/s) and injection orifice diameter (from about 0.5 to 2.5 mm). The tests were conducted under conditions of normal atmospheric pressure and temperature using still photography for penetration profile and a laser light scattering technique for mean dropsize determination. The experimental penetration data is shown to agree, reasonably accurately, with a relatively simple model developed in the paper. The analysis of the experimental breakup data reveals the airstream velocity as exercising the strongest influence upon Sauter Mean Diameter.

Mixing and Fuel Atomisation Effects on Premixed Combustion Performance

“…This gives an evaporation distance of 95 mm. The drop size measurements of Hussein et al (14) are similar to the present atomisation process. Their results, based on the mean jet velocity and a fuel orifice size of 0.4 mm, indicate an SMD of approximately 70 pm.…”

Gas and Liquid Fuel Injection Into an Enclosed Swirling Flow

“…For good air assisted fuel atomisation a large velocity difference between the fuel and air is required and this is achieved in the present design. The fuel penetration and atomisation studies of Hussein et al (16) are relevant to the present work. Their studies do not include fuel diameters as small as in the present work, but they include a study of a 0.5 mm fuel orifice in a 100 m/s air stream.…”

Liquid Jets in Subsonic Crossflow

“…Previous studies of liquid jets injected in crossflows have included analyses in subsonic [1][2][3][4][5][6][7][8][10][11][12][13][14][15][16][17][18][19][20][21][24][25][26][27] as well as supersonic airstreams 23,24,28,31,34,38 . Some studies have been conducted at atmospheric pressures 1,3,[10][11][12]17,18 , while others have tried to simulate gas turbine-like conditions by testing at elevated pressures 2,4,19,20 .…”

“…These differences could be attributed to the different measurement techniques, nonuniformity in defining the trajectories, and the effect of presence of boundary layers, which has not been quantified in any study present in the literature. Studies have used the transverse jet extremities 5,14 , mean streamline locations 39 , locations of maximum velocities 39 and the locations of maximum flux concentration 11,33 to correlate jet trajectories. Differences in measurement methods also affect the penetration predictions.…”