The velocity distribution of the liquid sheet formed by two low-speed impinging jets

Abstract

In this study, the local velocities of the liquid sheet formed by two low-speed impinging jets were directly measured using a LDV (laser Doppler velocimetry) instrument. The spatial distribution of the local sheet velocities at the forward part of the sheet and the effects of the impingement angle and jet velocity on the sheet velocities were examined. A parabolic velocity profile across the pre-impinging jet greatly affected the sheet velocity distribution, causing the sheet velocities to decrease while the azimuthal angle increased. This was attributed to the movement of a high velocity core, existing in the pre-impinging jets, to the region around the axis of the sheet. In the radial direction, the local sheet velocities were a little low around the impinging point, and remained constant, but then decreased near the edge of the sheet. The dependence of sheet velocities on the impingement angle was confirmed, and the tendency towards an even distribution of sheet velocities was found to increase as the impingement angle increased. With the exception of the lowest velocities measured near the edge of the sheet, the local sheet velocities at the forward part of the sheet were higher than the mean jet velocity.

A numerical study on the fluid flow and heat transfer in the confined jet flow in the presence of magnetic field

“…(6) and (7), we can derive a Poisson equation (8). The Poisson equation is solved to get the electric potential /.…”

“…There have been many experimental and numerical studies to investigate the flow structures and heat transfer mechanisms in detail to obtain the optimal operating conditions of impinging jet for different industrial and engineering applications [1][2][3][4][5][6][7][8][9][10][11][12]. Sparrow and Wong [1] derived the mass transfer correlation for the impinging slot-jet flows at the Reynolds number of 150 < Re < 950 using the naphthalene sublimation technique and the analogy of heat and mass transfer.…”

“…The control of vortex pairing enhanced or reduced heat transfer from the impinging surface because of the change of flow structures. Choo and Kang [8] measured directly the local velocities of the liquid sheet formed by two low-speed impinging jets using a LDV. They investigated the spatial distribution of the local sheet velocity as well as the effects of the impingement angle and jet velocity on the sheet velocity.…”

Collision of viscoelastic jets and the formation of fluid webs

“…1,2 The structure, kinematics and stability of thin films has been well studied both experimentally and analytically throughout the literature for Newtonian fluids. 1, [3][4][5] However, despite the importance of these fluids and flows to a host of commercial and industrial applications such as agrochemical spraying, spray coating, and ink jet printing, little work has been done to study the breakup of thin films of viscoelastic fluids. [6][7][8][9] The studies that do exist focus primarily on correlating atomization characteristics and droplet size distribution measurements to changes in polymer concentration, molecular weight and fluid rheology.…”

An experimental study on the distribution of the drop size and velocity in asymmetric impinging jet sprays

“…The shape and thickness of the impinging jets and the distribution of the drop size and velocity of the sprays were investigated by Ranz [2], Hasson and Peck [3], Kang et al [4] and Choo and Kang [5] with a stable liquid sheet with relatively low jet velocities. Couto and Bastos-Netto [6] and Ibrahim and Przekwas [7] investigated the atomization characteristics of impinging jets experimentally.…”