Engineering Commons^™

Engineering And Scientific Manpower- A Scarce Resource For The 1970'S, Merl Baker

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

Nonequilibrium Structure Of Argon Shock Waves, Harlan F. Nelson

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This theoretical study investigates the influence of (1) the nonequilibrium excited state population in the relaxation region and (2) line radiation in the precursor on shock wave structure by considering strong shock waves propagating at Mach 18 and 24 into a theoretical argon-like gas at a pressure of 1 cm Hg and a temperature of 300°K. The argon atom is modeled as having two bound states plus a continuum, and the calculations include finite atom-atom and electron-atom collisional ionization and excitation rates as well as continuum and line radiation. The electron gas is allowed to be at a different temperature …

An Optical Detector Of Water Droplets Within A Thermal Diffusion Chamber, Duane Burton Bush

Masters Theses

"A technique is investigated for counting water droplets formed in a vertical plate steady flow thermal diffusion chamber designed to count cloud condensation nuclei. The counting technique utilizes light scattering. The light source is a He-Ne laser. The detector is a photomultiplier tube. The technique differs from that used in instruments manufactured by Bausch and Lomb, Royco, Climet, etc., in that the aerosol is not passed through a capillary tube. Instead, the viewed volume is optically defined.

It was found that in the configuration tested, the viewed volume is not well enough defined for use with polydisperse aerosols, although the …

Parametric Resonance Of A Beam Subjected To A Sawtooth, Axial Force, Alfred George Richardson

Masters Theses

"This study considers the response of a perfectly elastic straight beam subjected to a periodic, non-harmonic, axial load. A two-mode solution is sought and the effects of axial inertia are included in the analysis. General equations of motion for the beam are developed and their stability is studied with the aid of an analog computer. Results are presented in graphical form. Regions of instability are defined for both modes. A region of combination resonance is also found to occur for the case of a two-mode solution with axial inertia. Typical response curves are presented and the effects of axial inertia …

Breakdown Of The Laminar Flow Regime In Permeable-Walled Ducts, E. M. Sparrow, G. S. Beavers, T. S. Chen, J. R. Lloyd

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The stability of laminar flow in a parallel-plate channel having one permeable bounding wall is investigated by means of linear theory. The analysis lakes account of the coupling of the disturbance, fields in the channel and in the permeable material and of velocity slip at the surface of the permeable wall. Complementary experiments are performed in which the breakdown of the laminar regime in flat rectangular ducts is identified from pressure-drop measurements and from flow visualization studies. The experiments cover the range of slip velocities from 15-30 percent of the mean velocity and, in addition, the case of zero slip …

Decision-Directed Detector For Overlapping Pcm/Nrz Signals, Cheng Wang, Thomas L. Noack

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A decision-directed (DD) technique for the detection of overlapping PCM/NRZ signals in the presence of white Gaussian noise is investigated. The performance of the DD detector is represented by probability of error PE versus input signal-to-noise ratio (SNR). To examine how much improvement in performance can be achieved with this technique, PE's with and without DD feedback are evaluated in parallel. Further, analytical results are compared with those found by Monte Carlo simulations. The results are shown in good agreement. © 1973, IEEE. All rights reserved.