585 research outputs found
Stimulation of Equine Hoof Growth Using a Counter-Irritant
The effects of a counter-irritant on stimulating hoof growth was tested on 6 mature horses. The counter-irritant, Irish Reducinet, was used in an effort to stimulate the growth rate of normal equine hoof tissue. As determined by measurements taken every thirty (30) days over a three (3) month period it is shown that a counter-irritant applied to the coronary band will stimulate the equine hoof growth rate. This research study was done to determine if there is any benefit to using a counter-irritant to increase hoof gtowth rate. An increase in the rate of hoof growth length would be valuable to the horse that has developed a quarter crack or lost a large portion of hoof wall due to over-reaching or forging. With accelerated growth rate the horse would be able to resume training or return to work at an earlier date than the non-treated horse with a simi liar condition
Ariel - Volume 8 Number 1
Executive Editor
James W. Lockard, Jr.
Issue Editor
Michael J. Grimes
Business Manager
Neeraj K. Kanwal
Managing Editor
Edward H. Jasper
University News
Richard J. Perry
World News
William D.B. Hiller
Opinions
Elizabeth A. McGuire
Features
Patrick P. Sokas
Sports Desk
Shahab S. Minassian
Managing Associate
Brenda Peterson
Photography
Robert D. Lehman, Jr.
Graphics
Christine M. Kuhnl
Increased Fidelity in Prediction Methods For Landing Gear Noise
An aeroacoustic prediction scheme has been developed for landing gear noise. The method is designed to handle the complex landing gear geometry of current and future aircraft. The gear is represented by a collection of subassemblies and simple components that are modeled using acoustic elements. These acoustic elements are generic, but generate noise representative of the physical components on a landing gear. The method sums the noise radiation from each component of the undercarriage in isolation accounting for interference with adjacent components through an estimate of the local upstream and downstream flows and turbulence intensities. The acoustic calculations are made in the code LGMAP, which computes the sound pressure levels at various observer locations. The method can calculate the noise from the undercarriage in isolation or installed on an aircraft for both main and nose landing gear. Comparisons with wind tunnel and flight data are used to initially calibrate the method, then it may be used to predict the noise of any landing gear. In this paper, noise predictions are compared with wind tunnel data for model landing gears of various scales and levels of fidelity, as well as with flight data on fullscale undercarriages. The present agreement between the calculations and measurements suggests the method has promise for future application in the prediction of airframe noise
Ariel - Volume 8 Number 3
Executive Editor
James W. Lockard, Jr.
Business Manager
Neeraj K. Kanwal
University News
Richard J . Perry
World News
Doug Hiller
Opinions
Elizabeth A. McGuire
Features
Patrick P. Sokas
Sports Desk
Shahab S. Minassian
Managing Editor
Edward H. Jasper
Managing Associate
Brenda Peterson
Photography Editor
Robert D. Lehman. Jr.
Graphics
Christine M. Kuhnl
Acoustics and Surface Pressure Measurements from Tandem Cylinder Configurations
Acoustic and unsteady surface pressure measurements from two cylinders in tandem configurations were acquired to study the effect of spacing, surface trip and freestream velocity on the radiated noise. The Reynolds number ranged from 1.15x10(exp 5) to 2.17x10(exp 5), and the cylinder spacing varied between 1.435 and 3.7 cylinder diameters. The acoustic and surface pressure spectral characteristics associated with the different flow regimes produced by the cylinders' wake interference were identified. The dependence of the Strouhal number, peak Sound Pressure Level and spanwise coherence on cylinder spacing and flow velocity was examined. Directivity measurements were performed to determine how well the dipole assumption for the radiation of vortex shedding noise holds for the largest and smallest cylinder spacing tested
Tandem Cylinder Noise Predictions
In an effort to better understand landing-gear noise sources, we have been examining a simplified configuration that still maintains some of the salient features of landing-gear flow fields. In particular, tandem cylinders have been studied because they model a variety of component level interactions. The present effort is directed at the case of two identical cylinders spatially separated in the streamwise direction by 3.7 diameters. Experimental measurements from the Basic Aerodynamic Research Tunnel (BART) and Quiet Flow Facility (QFF) at NASA Langley Research Center (LaRC) have provided steady surface pressures, detailed off-surface measurements of the flow field using Particle Image Velocimetry (PIV), hot-wire measurements in the wake of the rear cylinder, unsteady surface pressure data, and the radiated noise. The experiments were conducted at a Reynolds number of 166 105 based on the cylinder diameter. A trip was used on the upstream cylinder to insure a fully turbulent shedding process and simulate the effects of a high Reynolds number flow. The parallel computational effort uses the three-dimensional Navier-Stokes solver CFL3D with a hybrid, zonal turbulence model that turns off the turbulence production term everywhere except in a narrow ring surrounding solid surfaces. The current calculations further explore the influence of the grid resolution and spanwise extent on the flow and associated radiated noise. Extensive comparisons with the experimental data are used to assess the ability of the computations to simulate the details of the flow. The results show that the pressure fluctuations on the upstream cylinder, caused by vortex shedding, are smaller than those generated on the downstream cylinder by wake interaction. Consequently, the downstream cylinder dominates the noise radiation, producing an overall directivity pattern that is similar to that of an isolated cylinder. Only calculations based on the full length of the model span were able to capture the complete decay in the spanwise correlation, thereby producing reasonable noise radiation levels
Ariel - Volume 8 Number 4
Executive Editor
James W. Lockard Jr.
Issues Editor
Neeraj K. Kanwal
Business Manager
Neeraj K. Kanwal
University News
Martin Trichtinger
World News
Doug Hiller
Opinions
Elizabeth A. McGuire
Features
Patrick P. Sokas
Sports Desk
Shahab S. Minassian
Managing Editor
Edward H. Jasper
Managing Associate
Brenda Peterson
Photography Editor
Robert D. Lehman, Jr.
Graphics
Christine M. Kuhnl
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