Engineering Commons^™

Flow Visualization Studies Of Check Valve Vibrations, D. S. Weaver, F. A. Adubi

Symposia on Turbulence in Liquids

A swing-type hydraulic check valve was found to vibrate continuously when a damper was applied to prevent slamming. A research program was conducted to develop an understanding of the phenomenon and thereby determine a method of alleviation. This paper describes the flow phenomena observed during flow visualization studies of a two dimensional full scale model of the valve. Such observations give insight into the mechanism of vibration.

Session Chairman Introductory Remarks, T. J. Hanratty

Symposia on Turbulence in Liquids

No abstract provided.

Local Mass Transfer In Turbulent Flow By Electrochemical Methods, C. Deslouis, I. Epelboin, B. Tribollet, L. Viet

Symposia on Turbulence in Liquids

Mass transfer to the surface of rotating electrodes during turbulent flow was studied by electrochemical methods under steady and non-steady state diffusion conditions.

The flow was due to a large rotating disk made from insulating material, flush with the surface of which was mounted a ring shaped electrode of platinum or nickel.

A local study of the radial component of the convective diffusion in turbulent flow was carried out with very thin ring electrodes (width ΔR ~ 0,05 mm). The diffusion layer thickness was varied relatively to the diffusion sublayer thickness by changing the ring width or the rotation speed …

Compliant Wall Surface Motion And Its Effect On The Structure Of A Turbulent Boundary Layer, R. L. Ash, D. M. Bushnell, L. M. Weinstein, R. Balasubramanian

Symposia on Turbulence in Liquids

The status of the continuing compliant wall drag reduction research at NASA-Langley Research Center is discussed. Preliminary surface motion calculations are reported along with compliant surface design concepts and their numerical models. A compliant drag reduction theory based on stabilizing the turbulent substructure is proposed and previous experiments have been examined relative to that theory. Results of recent low speed compliant surface experiments have been reported which include initial attempts to measure local compliant surface motion.

Separation Of Low Reynolds Number Flows Around A Corner, T. Matsui, M. Hiramatsu, M. Hanaki

Symposia on Turbulence in Liquids

It was shown experimentally that low Reynolds number flows around a sharp corner do not separate at the corner, and separation points move downstream from the corner with decrease in Reynolds number. For the flow in a channel with a backward-facing step, the experimental results showed a good agreement with those of numerical calculation for the position of separation points and the length of standing vortices.

Some Observations Of Wake Behavior In Laminar And Turbulence Free Stream Flow, L. E. Seeley, R. L. Hummel, J. W. Smith

Symposia on Turbulence in Liquids

Visual observations of the sphere wake have been obtained using the flash photolysis technique. Free stream turbulence of 7 and 10% was found to progressively reduce the size of the wake but no turbulence was found in the attached shear layer nor was the position of the separation point affected. A separation bubble was identified as predicted by Son and Hanratty (1969). Evidence is presented to show that drag reduction in turbulent free streams is not due to turbulence in the attached boundary layer but to enhanced momentum transfer in the wake.

Stereoscopic Photography Of Shear Flow Turbulence, A. K. Praturi, H. C. Hershey, R. S. Brodkey

Symposia on Turbulence in Liquids

The last several years have seen numerous advances in the understanding of the coherent motions that exist in turbulent shear flows. These studies have provided the underlying basis of most of the experimental investigations of coherent motions using conditional sampling, quadrant splitting, pattern recognition, etc. Lacking, however, in the visual work is a true three- dimensional view of the processes, which are known to be three-dimensional in nature. Possible means of providing information about the third dimension are reviewed. Details of an evaluation of a stereoscopic-photographic, high-speed motion picture system are given. The system utilizes the boundary layer flow channel …

The Separation Angle For Spheres In A Pipeline, B. Latto, A. Lai

Symposia on Turbulence in Liquids

The results of a series of experiments on the measurement of the angle of separation for flow over steel spheres suspended in a vertical 5.18 cm ID pipeline with and without a drag reducing aqueous polymer solution are presented. Data were obtained for sphere- to-pipe diameter ratios of 0.74 and 0.925 with polymer concentrations of 0, 25, 50, and 100 wppm over a Reynolds number range of 1633 to 29400 for single spheres and trains of up to three spheres rigidly connected. It was found that relatively dilute polymer solutions can considerably affect the separation angle. Furthermore, that the angle …

The Roles Of Large Scale Structures In The Initial Development Of Circular Jets, F. K. Browand, J. Laufer

Symposia on Turbulence in Liquids

Experimental results are presented describing the flow field surrounding the potential core of a circular water jet in the Reynolds number region between 5,000 and 15,000. This field is divided into three regions: 1) the shear layer instability zone; 2) the vortex interaction region; and 3) the zone of higher order instability mode and turbulence generation. It is shown that the origin of the large scale structures just downstream of the potential cone can be traced to the upstream vortices, but their statistical behaviour (passage frequency, spatial coherence) seems to be independent of the initial shear layer instability.

Structure Of The Viscous Sublayer In Drag Reducing Channel Flows, W. G. Tiederman, A. J. Smith, D. K. Oldaker

Symposia on Turbulence in Liquids

The objective of this study was to experimentally determine the effect of dilute, long-chain, polymer solutions upon the flow processes in a fully developed, two-dimensional turbulent channel flow. This was accomplished by making motion pictures of dye seeped through a slot into the viscous sublayer. The motion pictures were analyzed to determine the span-wise spacing and the bursting rate of the low-speed streaks that are characteristic of the sublayer structure

Liquid Turbulence And Its Measurement, R. L. Humphrey

Symposia on Turbulence in Liquids

This paper covers several principles which have been successfully developed over the past few years and used in the measurement of liquid flows. In particular, ultrasonics, electro-magnetics, thermal heat transfer and optical light transmission will be discussed. Each concept will be covered by basic definitions and laws, theory of operation and application where measurement parameters will be highlighted, thus allowing the user to choose the best instrument to fit his experimental needs.

Communications And Group Decision-Making : Experimental Evidence On The Potential Impact Of Computer Conferenging, Computerized Conferencing & Communications Center, Starr Roxanne Hiltz

Computerized Conferencing and Communications Center Reports

This paper is a selective review of small group experiments in the area of the relationship between communication (modes, structures, processes) and group decision-making or problem solving. There are literally hundreds of these experiments; the purpose of this effort has been to isolate and summarize the results of those experimental traditions which may have the most bearing upon:

1. our understanding of the probable social effects of computer conferencing as a communication mode;
2. the identification of possible experiments utilizing computer conferencing which appear to be potentially most fruitful in terms of evaluating the strengths and weaknesses of computer conferencing in facilitating …

Turbulent Pressure Spectrum Measurements On A Compliant Surface, R. N. Brown

Symposia on Turbulence in Liquids

Experimental results obtained by measuring the drag, wall pressure fluctuations, and radiated sound from a compliantly coated cylinder, 21 inches in diameter, and rotating in water are described. The compliant layer was a 1/4-inch thick closed cell, air-filled neoprene which was mounted on the 3/8-inch thick aluminum cylinder walls. Results are presented for four speed conditions; one condition is below the speed where a sudden increase in drag is obtained, and the other speed conditions are at and above this critical speed. In general, the results indicate a surface which becomes increasingly more roughened as the critical speed is exceeded.

The Physical Background For Hot-Film Anemometry, G. Comte-Bellot

Symposia on Turbulence in Liquids

Thin film probes have been used for more than a decade to investigate turbulence, mostly in liquids. Many improvements have been achieved in the technique. Some problems still remain, however, so that the use of hot-film anemometers is not as straightforward as would be expected at a time when numerous ready-to-use probes and associated electronic equipment are commercially available. The following points should be discussed: aerodynamic perturbation caused by the probes, direct experimental check of the frequency response of constant temperature anemometers in the case of small fluctuations, dynamic non-linear behavior of constant temperature anemometers and heat transfer from hot …

Experimental Study Of Turbulence In Plane Separated Flows, R. Smyth

Symposia on Turbulence in Liquids

Some recent attempts at predicting turbulent two- dimensional recirculating flows have concentrated on modelling the turbulent energy equations used in the finite difference analysis methods of solutions of the elliptic partial differential equations governing these flows. These attempts have to some extent been restricted by the lack of experimental studies of the high turbulence intensities found in separated flows. The improvement of the pulsed hot-wire anemometer and the laser Doppler anemometer have made possible such studies and this paper describes an investigation using the laser Doppler anemometer in a separated flow situation. Results are given of an experimental study of …

Transverse, Pavement Markings For Speed Control And Accident Reduction, Kenneth R. Agent

Kentucky Transportation Center Research Report

Transverse pavement markings were placed ahead of a sharp curve having a high-accident history. Speed and accident studies were conducted before and after. The markings were placed so that drivers otherwise failing to reduce speeds while approaching the curve would see transverse lines on the pavement at an increasing rate. The spacing of lines was intended to create an illusion of acceleration which would cause the driver to slow. The results indicated that pavement markings can be an effective speed-control measure and reduce accidents. At the single site studied, the obedience of drivers to this type of hazard warning was …

Design Of Film—Substrate Single-Reflection Retarders, A.-R. M. Zaghloul, R. M.A. Azzam, N. M. Bashara

Electrical Engineering Faculty Publications

The design steps for film—substrate single-reflection retarders are briefly stated and applied to the SiO₂—Si film—substrate system at wavelength 6328 Å. The criterion of minimum-maximum error of the ellipsometric angle ψ is used to choose angle-of-incidence-tunable designs. Use is made of the (Φ-d) plane (angle of incidence versus thickness) to determine whether a given film—substrate system with known optical properties and film thickness can operate as a reflection retarder and to determine the associated angles of incidence and retardation angles. This leads to the concept of permissible-thickness bands and forbidden gaps for operation of a film—substrate …

Deposition Of Suspensions In Laminar Flow In The Entrance Region Ofa Channel And In A Diffuser, Shawki Mahmoud Eldighidy

Dissertations

In this investigation, the deposition of suspensions in laminar flow in the entrance region of a channel and a diffuser was considered.

The particulate phase was considered to he under the action of the electric field force clue to electrostatic charges. In addition, a lift force acting on each particle at the wall arising from the fluid shear near the wall and an adhesive force between each particle and the wall due to the difference of the material properties for both particle and walls were considered as surface forces.

The suspension flow was assumed to be incompressible, laminar, dilute, and …

Computer Program For Binary Distillation Using The Method Of Pochon-Savarit With Enthalpy Data Calculated By Lagrange Interpolation, Joseph J. Rogus

Theses

This thesis presents a Fortran Computer Program to solve binary distillation problems. The solution is obtained by the method of Pochon-Savarit which is based upon graphical use of an enthalpy-concentration diagram. The enthalpy data in this program is calculated using Lagrange interpolation. This is accomplished by utilizing the Lagrange interpolation to get values for the enthalpy of the vapor until we find that value which lies on the same line as the enthalpy of the liquid from the preceding tray and its corresponding del point.

The required input data consist of liquid-vapor equilibrium data, heat of solution data with the …

Initial Specifications Electronic Information Exchange System (Eie), Computerized Conferencing & Communications Center, Murray Turoff

Computerized Conferencing and Communications Center Reports

This document is intended as a SPECIFICATIONS MANUAL to guide the development of the EIE System. It does not represent a User Manual although it contains the specification of the user abilities on the system. It is written in a highly segmented style which reflects the potential use of the material in the on-line EXPLANATION file which will be available as part of the EIE System and which will allow users to retrieve just enough information to satisfy a specific question on system use and options.

This comprehensive specification document is much harder to utilize for learning the system than …

17th Annual Rocky Mountain Spectroscopy Conference

Rocky Mountain Conference on Magnetic Resonance

Final program and abstracts from the 17th annual meeting of the Rocky Mountain Spectroscopy Conference, sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, August 4-8, 1975.

Relativistic Scattered-Wave Theory, Cary Y. Yang, Sohrab Rabii

Electrical and Computer Engineering

A scattered-wave formalism based on the one-electron Dirac equation for a muffin-tin potential is presented. It is shown that the resulting relativistic secular equations reduce to their nonrelativistic counterparts in the infinite-rest-energy limit.

Pollution Of Surface Irrigation Waters By Plant Pathogenic Organisms, James R. Steadman, C. R. Maier, H. F. Schwartz, E. D. Kerr

Department of Plant Pathology: Faculty Publications

Systematic sampling of waterways and irrigation runoff from agricultural lands in the North Platte Project of Nebraska in July and August of 1972–1974 demonstrated that phytopathogenic organisms were disseminated. The organisms monitored included the bean common blight bacterium Xanthomonas phaseoli, the bean white mold fungus Whetzelinia sclerotiorum and various nematodes. Although many types of nematodes often were recovered from irrigation water, Heterodera sp. cysts which cause significant disease problems in the valley were found infrequently. Patterns of movement of the bacterial and fungal organisms were correlated with previous or current season infection of bean plants. The short-term survival of X. …

Loads On Box Culverts Under High Embankments: Positive Projection, Without Imperfect Trench, Rick L. Russ

Kentucky Transportation Center Research Report

This report describes the instrumentation and measurements of settlements and pressures on two box culverts in Clark County, Kentucky, designed without the imperfect trench -- one for yielding and one for unyielding foundation conditions. The structures were primarily instrumented for comparison with three structures previously constructed in McCreary County, which were designed using the imperfect trench method. Pressures on the two structures in Clark County generally exceed the product of the unit weight of the overlying material and its height. The pressures on the culverts in McCreary County appear to be lower than expected -- indicating that the imperfect trench …

Waviness Distortion In Mechanical Face Seals, Joseph J. Roesch

Mechanical Engineering ETDs

In this thesis the phenomenon of waviness distortion in mechanical face seal washers is investigated. Waviness in face seals leads to leakage in some applications. When leakage becomes significant, the seal must be replaced. If the distortion causing mechanism can be described, improvement in seal performance and behavior may be possible.

The components and function of the mechanical face seal are first discussed. It is seen that only one component of the seal unit shows significant deterioration over a period of time. It is also seen that this component, the face washer, wears in a characteristic manner. The characteristics of …

Steady State Fluidics: The Static Matching Of Fluidic Amplifiers And Loads, Frank J. Redd

Theses and Dissertations

"Fluidics" is the title applied to a relatively new technology which is concerned with the control of fluid power and the processing of information through the use of the fluid mechanical properties of the fluid medium itself. The absence of moving parts and the relatively low sensitivity to enviromental conditions suggest the probability that fluidic systems will prove to be faster and more reliable than the mechanically controlled (valves, diaphragms, springs, etc.) fluid systems which they are designed to replace.

Computer Aided Design For Fluidic Sequential Circuits Of Fundamental Mode, Yau-Hwang Lee

Dissertations and Theses

This thesis presents the method of state diagram synthesis and the development of a computer program for designing fluidic sequential feedback control circuits of the fundamental mode. A paper on state diagram synthesis was authored by Chen and Lee, presented in Detroit and published as ASME paper 73-WA/Flcs-2 in 1973.

Hypothetical systems are illustrated by using series of events characterized by the piston positions of some double-acting pneumatic cylinders. In these systems , an action can only begin when the previous action has been completed. Every extension or retraction of a piston is memorized and manifested by a flip-flop element …

Investigation Of Electron-Beam Deposited Titanium Dioxide On Silicon For Application In Mos Devices, William David Brown

Electrical and Computer Engineering ETDs

Titanium dioxide (Ti02) has been studied to determine the feasibility of using this dielectric material in Metal-Insulator-Semiconductor (MIS) structures. MIS structures utilizing various dielectric materials have received considerable attention in recent years. Materials such as titanium dioxide which exhibit a high permittivity are attractive as insulators in MIS devices because of high capacitive density, good surface control for thick films, large power handling capability, and reduction in device size.

Ar 10-50, Organization And Functions, United States Army Medical Intelligence And Information Agency, 16 July 1975., Headquarters, Department Of The Army, Robert Bolin , Depositor

United States Department of Defense Military Intelligence

The purpose of the regulation is described as setting “… forth the mission and principle functions of the United States Medical Intelligence and Information Agency, a Field Operating Agency of the Office of The Surgeon General…”[US Army]. In other words, the MIIA is a special purpose organization reporting to The Surgeon General, chief of the Army Medical Department and senior medical staff officer in the US Department of the Army.

The mission of the MIIA…”is to produce medical scientific and technical intelligence (S&TI) and general medical intelligence (GMI) studies required by the Department of Defense; to provide timely medical intelligence …

An Examination Of Thermal Stress As A Mechanism For Cladding Failure In A Hypothetical Lmrbr Transiet, Douglas Wakerfield Croucher

Nuclear Engineering ETDs

Stainless steel clad uranium dioxide fuel pellets were pulse irradiated in the Annular Core Pulse Reactor to evaluate thermal stress as a contributing mechanism for cladding failure in hypothetical LMFBR transients. The 6.2 mm diameter UO2 fuel pellets, with enrichments up to 25 w/o 235UO2, were helium bonded to 0.381 mm thick Type-316 stainless steel cladding and were irradiated in a helium environment with reactor pulses having initial periods as short as 1.5 milliseconds. In experiments conducted elsewhere with longer initial periods, the primary fuel failure mechanisms observed were differential fuel-cladding thermal expansion, intragranular fission-gas-induced fuel swelling, transient fission gas …