During its near-ground hovering phase a Short Take-Off and Vertical Landing (STOVL) aircraft creates a complex three-dimensional flow field between jet streams, the airframe surface and the ground. A proper understanding and numerical prediction of this flow is important in the design of such aircraft. In this paper an experimental facility, used to gather validation data suitable for testing C...

The unsteady two-dimensional flow of a viscoelastic second-grade fluid impinging on an infinite plate is considered. The plate is making harmonic oscillations in its own plane. A finite difference technique is employed and solutions for small and large frequencies of the oscillations are obtained. 1. Introduction. In the past two decades, the importance of non-Newtonian viscoelastic liquids hav...

This study experimentally investigates the generation mechanism of a higher-angle lobe which is an acoustic field feature supersonic jet impinging on inclined flat plate. The overall sound pressure level distribution and spectra, conditional averages near schlieren movies, time-averaged wall were obtained for three cases Mach 1.8 ideally expanded jets with plate angles 45°, 22.5°, 10° to downst...

investigation on local scour phenomenon downstream of impinging jets is very complicated. different parameters such as geometry of stream, characteristics of flow and sediments have great influences on the scour phenomenon. the present study is preceded to numerical modeling of scouring by impinging jet via ssiim 2 model founded on a physical model tests. the numerical model is calibrated for r...

T he contact angle of a droplet impinging upon a hot surface undergoes changes as the drop spreads and recoils. The motion of the liquid and the effect of evaporation from the edges of the drop affect the contact angle. The changes in the contact angle during spreading affect the spreading characteristics of the droplet upon impact. However, the models available in literature for the maximum sp...

This paper proposes a novel direction of arrival (DOA) estimation scheme using particle swarm optimization (PSO)-based SPECC (Signal Parameter Extraction via Component Cancellation). The proposed algorithm is a PSO-based optimization method and extracts the amplitudes and incident angles of signal sources impinging on a sensor array in a step-by-step procedure. On the other hand, other algorith...

In this paper, we analyze the transmission properties of metallic gratings at optical frequencies. In particular, we show that an inherently ultra-broadband tunneling mechanism may be obtained based on impedance matching between the guided modes supported by ultranarrow slits and freespace TM plane waves impinging at an oblique angle. This phenomenon is the analogous of the well-known Brewster ...