Axisymmetric jets impinging perpendicularly on a wall are encountered in a variety of real-life situations such as Chemical Vapor Deposition (CVD) processes (Goodwin, 2003). Although the fluid mechanics of the wall-impinging jets are interesting phenomena in their own right, this topic is studied here for two reasons. The first is to assess the extent to which experimental data and numerical da...

This paper reviews several aspects of liquid jet impingement cooling, focusing on research done in our lab at MIT. Free surface, circular liquid jet are considered. Theoretical and experimental results for the laminar stagnation zone are summarized. Turbulence effects are discussed, including correlations for the stagnation zone Nusselt number. Analytical results for downstream heat transfer in...

Rapid freeze-quench (RFQ) trapping of short-lived reaction intermediates for spectroscopic study plays an important role in the characterization of biological reactions. Recently there has been considerable effort to achieve submillisecond reaction deadtimes. We present here a new, robust, high-velocity microfluidic mixer that enables such rapid freeze-quenching. It is a based on the mixing met...

Sound generation by confined stationary jets is of interest to the study of voice and speech production, among other applications. The generation of sound by low Mach number, confined, stationary circular jets was investigated. Experiments were performed using a quiet flow supply, muffler-terminated rigid uniform tubes, and acrylic orifice plates. A spectral decomposition method based on a line...

Behavior of unconfined transverse jets has been studied extensively, but little work is reported on the flow characteristics of confined transverse jets. The latter has been numerically investigated using a number of RANS codes. The computational results obtained from these codes have been evaluated against the existing experimental data, and an LES results reported in the literature. Furthermo...

The circular hydraulic jump exhibits behavior quite different from that commonly observed in planar jumps. Here we examine experimentally some of the causes and consequences of those differences. We suggest that surface tension plays a dominant role in establishing the shape of the circular jump for impinging jets. The importance of surface tension is a direct result of the thinness of the liqu...

This contribution presents different approaches for the modeling of air entrainment under water by plunging jets in CFD codes. In simulations which include the full length of the jet and its environment, the process of bubble generation can not be resolved due to computational limitations. This is why the air entrainment has to be modeled in meso-scale simulations. In the frame of an EulerEuler...

We analyze the flow of a planar gas jet impinging on thin film, dragged by vertical moving wall. In coating industry, this configuration is known as wiping, process in which jets control thickness liquid coatings flat plates withdrawn vertically from bath. present three-dimensional (3D) two-phase simulations combining Large Eddy Simulation (LES) and Volume Fluid (VOF). Three wiping configuratio...

For fundamental analysis of the transport of mass or heat in a dispersed system, accurate knowledge of behavior of jet is prerequisite. For generation of high interfacial area breaking of liquid jet in to small droplet is necessary. Liquid jet breakup is a complex phenomenon and dependent on many factors like velocity of jet, pressure difference, geometry of nozzle, temperature of both fluid, p...