This study explores the single-phase cooling performance of a hybrid cooling module in which a series of micro-jets deposit coolant into each channel of a micro-channel heat sink. This creates symmetrical flow in each micro-channel, and the coolant is expelled through both ends of the micro-channel. Three micro-jet patterns are examined, decreasing-jet-size (relative to center of channel), equa...

BACKGROUND AND PURPOSE Inflow jet characteristics may be related to aneurysmal bleb formation and rupture. We investigated the visualization threshold on the basis of the flow velocity in the parent artery to classify the inflow jet patterns observed on 4D flow MR imaging. MATERIALS AND METHODS Fifty-seven unruptured aneurysms (24 bifurcation and 33 sidewall aneurysms) were subjected to 4D fl...

Direct numerical simulation is used to study a round turbulent jet in a laminar crossflow. The ratio of bulk jet velocity to free-stream crossflow velocity is 5.7 and the Reynolds number based on the bulk jet velocity and the jet exit diameter is 5000. The mean velocity and turbulent intensities from the simulations are compared to data from the experiments by Su & Mungal (2004) and good agreem...

This paper presents the design, development and characterization of contractile water jet thruster (CWJT) for mini underwater robot. Instead of electric motor, this CWJT utilizes the Ionic Polymer Metal Composite (IPMC) as the actuator to generate the water jet. The main focus of this paper is to analyze the conceptual design of the proposed CWJT which would determine the thrust force value, je...

Pulsating cone-jets occur in a variety of electrostatic spraying and printing systems. This paper reports an experimental study of the pulsation frequency to reconcile two models based on a choked jet and an oscillating cone, respectively. The two regimes are demarcated by the ratio of the supplied flow rate (Qs) to the minimum flow rate (Qm) required for a steady Taylor cone-jet. When Qs . Qm,...

An experimental study of plasma jet at atmospheric pressure was carried out to examine the influence of external transverse magnetic field on it. A magnetic field was applied to the jet in atmospheric pressure by means of a pair of coils, same Helmholtz coil configuration. It was applied transverse to the jet flow. The strength of the direct current magnetic field was 00.057 Tesla between the t...

An experimental investigation of sonic air, CO2 and Helium transverse jets in Mach 5 cross flow was carried out over a flat plate. The jet to freestream momentum flux ratio, J, was kept the same for all gases. The unsteady flow topology was examined using high speed schlieren visualisation and PIV. Schlieren visualisation provided information regarding oscillating jet shear layer structures and...

The analysis of katabatic flows is often complicated by heterogeneity in surface characteristics. This study focuses on an idealized type of katabatic flow driven by a simple form of inhomogeneous surface forcing: a buoyancy or buoyancy flux that varies down the slope as a top-hat profile (cold strip). We consider the two-dimensional Boussinesq system of governing flow equations with the slope ...

Numerical simulations are used to study an under-expanded sonic jet injected into a supersonic crossflow and an over-expanded supersonic jet injected into a subsonic crossflow, where the flow conditions are based on Santiago et al.’s (1997) and Beresh et al.’s (2005) experiments, respectively. A finite volume compressible Navier–Stokes solver developed by Park & Mahesh (2007) for unstructured g...

Although the hydraulic jump has been investigated experimentally for nearly two centuries, little information is known of the air-water flow properties in the shear region. New experiments were performed in a horizontal channel with partially-developed inflow conditions. Distributions of air concentration, mean air-water velocity and bubble frequency were recorded and presented herein. The resu...