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Laminar/Turbulent Oscillating Flow In Circular Pipes, Kyung H. Ahn, Mounir B. Ibrahim
Laminar/Turbulent Oscillating Flow In Circular Pipes, Kyung H. Ahn, Mounir B. Ibrahim
Mechanical Engineering Faculty Publications
A two-dimensional oscillating flow analysis was conducted simulating the gas flow inside Stirling engine heat exchangers. Both laminar and turbulent oscillating pipe flow were investigated numerically for Remax = 1,920 (Va = 80), 10,800 (Va = 272), 19,300 (Va = 272), and 60,800 (Va = 126). The results are here compared with experimental results of previous investigators. Predictions of the flow regime on present oscillating flow conditions are also checked by comparing velocity amplitudes and phase difference with those from laminar theory and quasi-steady profile. A high Reynolds number k-ε turbulence model was used for turbulent oscillating pipe flow. …
Comparison Of Analysis And Experiment For Gearbox Noise, Fred B. Oswald, A. F. Seybert, T. W. Wu, William J. Atherton
Comparison Of Analysis And Experiment For Gearbox Noise, Fred B. Oswald, A. F. Seybert, T. W. Wu, William J. Atherton
Mechanical Engineering Faculty Publications
Low-contact-ratio spur gears were tested in the NASA gearnoise rig to study the noise radiated from the top of the gearbox. Experimental results were compared with a NASA acoustics code to validate the code for predicting transmission noise. The analytical code is based on the boundary element method (BEM) which models the gearbox top as a plate in an infinite baffle. Narrow-band vibration spectra measured at 63 nodes on the gearbox top were used to produce input data for the BEM model. The BEM code predicted the total sound power based on this measured vibration. The measured sound power was …
Effect Of Operating Conditions On Gearbox Noise, Fred B. Oswald, James J. Zakrajsek, Dennis P. Townsend, William Atherton, Hsiang Hsi Lin
Effect Of Operating Conditions On Gearbox Noise, Fred B. Oswald, James J. Zakrajsek, Dennis P. Townsend, William Atherton, Hsiang Hsi Lin
Mechanical Engineering Faculty Publications
Low-contact-ratio spur gears were tested in the NASA gear noise rig to study the noise radiated from the top of the gearbox. The measured sound power from the gearbox top was obtained from a near-field acoustic intensity scan taken at 63 nodes just above the surface. The sound power was measured at a matrix of 45 operating speeds and torque levels. Results are presented in the form of a spectral speed map and as plots of sound power versus torque (at constant speed) and as sound power versus speed (at constant torque) Because of the presence of vibration modes, operating …