Open Access. Powered by Scholars. Published by Universities.®

Mechanical Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 2 of 2

Full-Text Articles in Mechanical Engineering

The Effects Of Transverse Vibration On The Performance Of An Axial Groove Wick Heat Pipe, Kenneth A. Carpenter Dec 1994

The Effects Of Transverse Vibration On The Performance Of An Axial Groove Wick Heat Pipe, Kenneth A. Carpenter

Theses and Dissertations

An experimental investigation was performed to determine the effects of transverse vibrations on the performance of an ammonia-aluminum axial groove wick heat pipe. Theoretical calculations predicted a performance degradation due to the working fluid being shaken out of the upper capillary grooves. A benchtop shaker was used to apply transverse, sinusoidal vibrations of 30, 35, and 40 Hertz, corresponding to peak acceleration amplitudes of 1.84g, 2.50g, and 3.27g, respectively. Maximum heat throughput, Q sub max, of the vibrating heat pipe was measured. A comparison of these values and static Q sub max values indicated a degradation in heat pipe performance. …


Effects Of Blowing Ratio On Heat Transfer To The Throat Region Of A Porous-Walled Nozzle, Joseph L. Lenertz Dec 1994

Effects Of Blowing Ratio On Heat Transfer To The Throat Region Of A Porous-Walled Nozzle, Joseph L. Lenertz

Theses and Dissertations

This experiment analyzed the effects of blowing ratio on heat transfer to the throat region of a porous-walled nozzle, using the AFIT low speed shock tube. Heat flux data were taken from both sides of a two-dimensional Mach 2.0 Re-m=5.2x107 nozzle using thin film resistance thermometers. One side was transpiration-cooled by secondary air injection through a sintered wall, while the other side served as a control. Control results were validated using empirical relations, and cooled side results showed up to a 14% reduction in heat transfer coefficient at blowing ratios of only 0.51%. The linear nature of cooling effectiveness …