Primary Breakup of Turbulent Round Liquid Jets in Uniform Crossflows

Abstract

An experimental investigation of the deformation and breakup properties of turbulent round liquid jets in uniform gaseous crossflows is described. Pulsed shadowgraph and holograph observations were obtained for turbulent round liquid jets injected normal to air crossflow in a shock tube. Crossflow velocities of the air behind the shock wave relative to the liquid jet were subsonic (36-90 m=s) and the air in this region was at normal temperature and pressure. Liquid injection was done by a pressure feed system through round tubes having inside diameters of 1 and 2 mm and length-to-diameter ratios greater than 100 to provide fully developed turbulent pipe flow at the jet exit. Test conditions were as follows: water and ethyl alcohol as test liquids, crossflow Weber numbers based on gas properties of 0-282, streamwise Weber numbers based on liquid properties of 1400-32,200, liquid/gas density ratios of 683 and 845, and jet exit Reynolds numbers based on liquid properties of 7100-48,200, all at conditions in which direct effects of liquid viscosity were small (Ohnesorge numbers were less than 0.12). Measurements were carried out to determine conditions required for the onset of breakup, ligament and drop sizes along the liquid surface, drop velocities after breakup, liquid column breakup as whole, rates of turbulent primary breakup, and liquid column trajectories. Phenomenological theories proved to be quite successful in interpreting and correlating the measurements.

Injection of Water-in-Oil Emulsion Jets Into a Subsonic Crossflow: An Experimental Study

“…Lee and co-workers reported on the phenomenological properties for a high Reynolds number subsonic crossflow; the Re N is shown to be the dominant breakup mechanism due to turbulent eddies near the liquid surface (Lee et al, 2007). The current investigation produces nonturbulent Re N from 1300 to 8400 and, from the current statistical regression analysis, was not shown to produce a primary governing effect.…”

“…If only the shear and multi-breakup modes were considered, C D should vary only slightly, roughly from values of 3 to 4. Considering the equation form from the findings of Lee et al (2007) in Eq. (9), C D correlates inversely to the 1/2 power with trajectory, attributing to a small effect in the current case, which leaves eight usable groupings in Eq.…”

“…(7) and (8). Work by Lee et al (2007) investigated the penetration of round turbulent jets in a crossflow over a large range of q from 3 to 200 and included the liquid column drag coefficient (C D ) as shown in Eq. (9), which was set to a constant value of 3 for shear breakup.…”

Spray Atomization Models in Engine Applications, from Correlations to Direct Numerical Simulations

“…Many studies and correlations describe the SMD depending on the distance to the nozzle or on the breaking type or phase (Wu and Faeth, 1995;Faeth, 1996;Lee et al, 2007).…”

Azimuthal shear instability of a liquid jet injected into a gaseous cross-flow

“…Thus, similar to their set-up, in this study the primary breakup of the jet is caused by the cross-flow rather than by jet turbulence (which could lead to other breakup processes such as turbulent primary breakup (see e.g. Lee et al 2007)). …”