Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 5 of 5
Full-Text Articles in Engineering
Flow Visualization Study Of Passive Flow Control Features On A Film-Cooled Turbine Blade Leading Edge, Daniel R. Carroll
Flow Visualization Study Of Passive Flow Control Features On A Film-Cooled Turbine Blade Leading Edge, Daniel R. Carroll
Theses and Dissertations
A flow visualization study was conducted on a model of a film-cooled turbine blade leading edge in a closed-loop water channel at ReD = 30k. The model consisted of an 8.89 cm diameter half-cylinder with flat afterbody joined at the ninety degree point. A single radial coolant hole (dc / D = 0.054) drilled 21.5° from the stagnation line, angled 20° to the surface and 90° to the flow direction generated a coolant jet transverse to the freestream. Water channel testing assessed the hydrodynamic effects of 16 passive flow control features, to include a variety of …
The Aerodynamic Performance Of The 24 Inch Houck Configuration, Michael M. Walker
The Aerodynamic Performance Of The 24 Inch Houck Configuration, Michael M. Walker
Theses and Dissertations
Fuel efficiency of aircraft is of great importance to the military and private sector. A more efficient wing design for UAVs would lead to improvements in mission support while reducing fuel costs for the Air Force. An experimental investigation of one candidate design, the Houck Aircraft Configuration, has been conducted in the AFIT low speed wind tunnel. This aircraft shares similarities to other joined-wing aircraft, but includes curved flow-guides of varying spanwise camber connecting the upper and lower wingtips. Experimental results that the addition of flow guides on the 24" Houck Configuration results in a 2.5% reduction in L/D(sub max) …
Characterizing A Co-Flow Nozzle For Use In A Filtered Rayleigh Scattering System, David S. Miceli
Characterizing A Co-Flow Nozzle For Use In A Filtered Rayleigh Scattering System, David S. Miceli
Theses and Dissertations
Research was conducted on the flow field exiting a co-annular flow nozzle for use in filtered Rayleigh scattering flow visualizations. More specifically, the flow visualizations were of the flow field exiting a coflow nozzle and illuminated by a tunable, nominal 4.2 watt narrow line width Argon laser operating at 514.5nm. ND:YAG lasers are typically used in this application, but some of the properties of a tunable Argon laser make it an attractive alternative. Before generating flow visualizations, the coflow nozzle was characterized both experimentally and computationally. Due to a flow asymmetry in the outer annulus flow field, the nozzle was …
Boundary Layer Flow Control Using Plasma Induced Velocity, Brian E. Balcer
Boundary Layer Flow Control Using Plasma Induced Velocity, Brian E. Balcer
Theses and Dissertations
An examination of the effects of plasma induced velocity on boundary layer flow was conducted. A pair of thin copper film electrodes spanned the test section, oriented at thirty degrees from normal to the free stream flow. An adverse pressure gradient was imposed over the electrode configuration using a pressure coefficient profile similar to that associated with suction side of a Pac-B low pressure turbine blade. In addition, suction was applied to keep flow attached on the upper wall, inducing separation over the electrode. The electrode is supplied by an AC source at three different power levels with the free …
Flow Visualization Of A Turbulent Shear Flow Using An Optical Wavefront Sensor, Daniel W. Jewell
Flow Visualization Of A Turbulent Shear Flow Using An Optical Wavefront Sensor, Daniel W. Jewell
Theses and Dissertations
The research reported here investigated the use of a shearing interferometer (SI) wavefront sensor to determine the effects of shear-layer turbulence on an optical wavefront. A collimated helium-neon laser beam was propagated through a plane shear-layer produced by mixing helium and nitrogen at different velocities. Since the gases have different indices of refraction, the optical wavefront was distorted by different amounts by each gas. The SI measured the wavefront slope across the sampled area of the wavefront. The shear-layer was viewed from two orthogonal directions. This document contains shadow graphs, interference patterns imaged by each of the SI's six cameras, …