Engineering Commons^™

The Use Of Electrochemical Techniques To Study Turbulence Close To A Wall, Kamalesh K. Sirkar, Thomas J. Hanratty

Symposia on Turbulence in Liquids

Electrochemical techniques can be used to measure the time averaged velocity gradient and the two components of the fluctuating velocity gradient at a solid surface. A chemical reaction Is carried out at the surface of a small electrode embedded in the wall. The voltage applied to the electrode Is large enough that the current flowing in the circuit is controlled by the mass transfer rate. The probes are the mass transfer analog of the hot wire or hot film anemometer. If the test electrode is part of a large electrode surface, it can be used to measure local time averaged …

Ultrasonic Study Of Turbulent Water Flow, W. K. Kramer, R. Grosskreutz, A. Dinkelacker

Symposia on Turbulence in Liquids

The propagation of ultrasonic waves through turbulent water flow has been Investigated experimentally. While passing the turbulent region the sound waves are modulated to some extent. The degree of modulation and the frequency spectra of the modulation are closely related to the properties of the flow. It seems to be possible to use this method for turbulence measurements in liquids, whereby the absence of a probe in the flow region and a possibility to differentiate between velocity and density fluctuations would be special advantages. A disadvantage can be the fact that Information is collected on the whole sound path.

Turbulence Measurements In Water, Francois J. Resch

Symposia on Turbulence in Liquids

Turbulence measurements in water have been undertaken using hot film anemometers in a circular conduit. Two different types of film probe were tested and the problem of drift of the calibration curves was carefully studied. A heat transfer law was established for conical hot film probes.

Some turbulence measurements, made at the axis of the pipe, were compared with the corresponding measurements undertaken in air flow. The comparison led to the conclusion that turbulence measurements can be carried out in water with the same degree of accuracy as those carried out in dynamically similar air flow.

Two-Dimensional Laser-Doppler Velocimetry In Turbulent Flows, N. E. Chatterton, R. D. Lewis, E. W. George

Symposia on Turbulence in Liquids

Localized measurement of the velocity of flow In fluids may be accomplished by detecting the Doppler shift In frequency from coherent, monochromatic light scattered from micrometer sized contaminant particles within the flow. The versatility of applications of this technique, first used several years ago, has been expanded by recent research. The basic geometry of measurement, in which the scattered energy is recombined with light energy at the original frequency on the face of the photocathode of a photomultiplier tube, can be rearranged in many alternative configurations to meet the needs of the experimenter. By using a single laser, additional arrangements …

Turbulence Measurements In Shear Flow Liquid Systems, Robert S. Brodkey, M. F. Cohen, J. S. Knox, G. L. Mckee

Symposia on Turbulence in Liquids

The paper is a composite of a number of years of work on turbulence measurements in a variety of liquid flow systems. The trials and tribulations of such measurements are emphasized. Pipe flow Is considered in some detail, and the consistency between results of various investigators is analyzed. Other systems discussed are a stirred tank unit and a multi-jet reactor configuration. Statistical turbulence measurements such as autocorrelation, spectrum, probability density, flatness factor, and skewness factor are considered in terms of obtaining these from digital signals obtained by conversion of the normal analog signals. Descriptive parameters of statistical turbulence, such as …

Bibliography Of Hot-Wire-Film Anemometry In Liquids, R. L. Humphrey

Symposia on Turbulence in Liquids

It is not a new idea to use heat transfer from a hot sensor in a fluid stream to measure velocity and turbulence. This was done as long ago as 1909 by Mr. Kenelly, but a systematic study was not followed through until 1914 by L. V. King. After this followed a series of dedicated people, some students, some professors, some scientists, who continually advanced the state of the art of anemometry in liquids. This paper deals with their work in the areas of electronics (integrated circuits) and physics (thin film technology), and shows how, in time, these two areas …

Some Basic Properties Of Low Quality Two-Phase Turbulent Flow, G. Hetsroni, S. Einav

Symposia on Turbulence in Liquids

This Is an exploratory study dealing with the effect of gas bubbles on the turbulence Intensity of the liquid in a two-phase flow.

Distributions of time-mean and fluctuating velocities were measured in a two - dimensional channel. These were measured for single-phase flow and on the two sides of a bubble layer, which simulated the two-phase flow.

In single-phase flow the distribution of the time-mean velocities agrees well with other data, while the distribution of the Intensity of turbulence Is lower than expected.

The measurements of the time-mean velocity and turbulence Intensity across the bubble layer revealed that they are …

Turbulence Measurements In Stably Stratified Fluids, Yih-Ho Pao

Symposia on Turbulence in Liquids

A towing tank system was used to study the structure of turbulence in stably stratified fluids. Turbulence is generated by moving an obstacle (a grid or a cylinder) in a tank of stratified salt water. Recent improved shadowgraph pictures of these laboratory generated stratified flows are shown in this paper. They give further support to Pao's observation that (i) internal waves and turbulence coexist in turbulent stratified flows, with internal waves at the large scales and turbulence at the small scales; (ii) turbulence decays much more rapidly than internal waves; and (iii) the turbulent-nonturbulent interfaces are not necessarily sharp, and …

The Response Of A Hot-Wire Anemometer To A Bubble Of Air In Water, S. C. Chuang, V. W. Goldschmidt

Symposia on Turbulence in Liquids

The sensitivity of peak voltage drop and duration of the change In sensor voltages due to the impaction of different size bubbles are confuted and measured. Excellent agreement between these is found for bubbles somewhat larger than the sensor diameter and smaller than Its effective length in water streams in a range of 1.5 to 9 feet per second. The method suggests a reliable method for sizing bubbles in a water stream. The effects due to nondirect hits are not treated.

Experimental Investigation Of Polymer Solution Injection On External Boundary Layers, Brian Latto, Chi-Hung Shen

Symposia on Turbulence in Liquids

This paper describes an experimental study of the effects of injecting dilute aqueous polymer solutions into a turbulent boundary layer formed on a flat plate immersed in flowing water.

Hot-film anemometer techniques were employed in the measurement of the velocity profiles, turbulence intensities, and lateral correlation coefficients at a number of locations along the plate. Boundary layer growth parameters and the variation of the local skin friction coefficient were computed from the velocity profile data. The effects of polymer concentration and injection velocity on the local drag reduction are also presented.

It was found that momentum diffusivity was smaller than …

Turbulence Measurements In Dilute Polymer Flows, Joseph M. Wetzel, John A. Almo, John M. Killen

Symposia on Turbulence in Liquids

A hot-film sensor was flush-mounted in the wall of a four-inch pipe and was calibrated as a function of wall shear stress. Flows with water and with homogeneous aqueous solutions of Polyox WSR-301 were utilized. The heat transfer characteristics of the sensor were reduced for polymer flows. Measurements of the number of zeroes and the frequency spectra for the turbulent fluctuations were obtained for a variety of test conditions. The effects of Polyox WSR-301 on surface pressure fluctuations on both smooth and rough surfaces were also measured.

An Experimental Facility For The Visual Study Of Turbulent Flows, Robert S. Brodkey, Harry C. Hershey, Edward R. Corino

Symposia on Turbulence in Liquids

An experimental technique which allows visual observations of the wall area in turbulent pipe flow is described in detail. It requires neither the introduction of any injection or measuring device into the flow nor the presence of a two-phase flow or of a non-Newtonian fluid. The technique involves suspending solid MgO particles of colloidal size in trichloroethylene and photographing their motions near the wall with a high speed movie camera moving with the flow. Trichloroethylene was chosen in order to eliminate the index of refraction problem in a curved wall.

Evaluation of the technique including a discussion of limitations is …

Experimental Investigation Of The Hydrodynamic Stability Of Flow In Rotating Pipes Using Thermistors, Hassan M. Nagib, Ludwig Wolf Jr.

Symposia on Turbulence in Liquids

The hydrodynamic stability of flow in a rotating pipe Is investigated experimentally using thermistors. The experimental apparatus consists of a rotating pipe made of lucite, 3-1/4 inch inside diameter, six feet long, equipped with porous plugs at the ends to minimize recirculation. The working fluid is water and a range of axial and tangential Reynolds numbers up to 7,000 and 20,000, respectively, is covered. Thermistors were chosen for this study since their high electrical resistivity yields strong signals which permit the use of inexpensive and convenient electronics. They also have a high temperature coefficient of electrical resistance which minimizes the …

The Structure Of A Turbulent Water Jet, Philip J. Morris

Symposia on Turbulence in Liquids

Experimental studies are made to determine the structure of a turbulent water jet.

The paper is divided into two parts. The first gives practical information about the techniques and instrumentation developed to make measurements with hot-wire anemometers in water. A short theoretical discussion is given on the dynamic response of heated fibre in liquids. The second part reports on the results obtained in a one-inch water jet at Reynolds numbers between 12,000 and 20,000. Mean axial velocity measurements are made in the initial five diameters of the jet and the results are used to predict the nature of the vortex …

Author Index, University Of Missouri--Rolla

Symposia on Turbulence in Liquids

No abstract provided.

Diffusion Coefficients Over Rough And Smooth Boundaries, Obtained By Measuring The Concentration-Velocity Covariance, R. S. Mcquivey, T. N. Keefer

Symposia on Turbulence in Liquids

A preliminary investigation of the coefficients of turbulent diffusion in an open channel was conducted by employing: 1) hot-film anemometry to detect the velocity fluctuation, 2) a platinized single-electrode conductivity probe to detect the concentration fluctuations, and 3) a digital computing system to evaluate the covariance and other statistical properties of the two output signals.

Data were collected downstream of a constant-discharge point source of neutrally-bouyant salt solution at stream temperature and velocity. Using current semi-empirical methods diffusion coefficients were obtained in the vertical and lateral directions as well as dispersion coefficients due to convection.

Use Of A Constant Temperature Hot-Wire Anemometer To Compensate For The Thermal Lag, Peter Freymuth

Symposia on Turbulence in Liquids

A constant temperature hot-wire anemometer can be used to compensate for the thermal lag of a wire or film resistance thermometer within the useful frequency range of the anemometer. This method may be used as an alternative to the standard method in which a differentiation circuit as employed in constant current anemometers is used for frequency compensation. The new method is useful if a constant temperature anemometer is at hand. The time constant of the resistance thermometer need not be determined.

Frequency Response Studies For A Wedge Probe In Viscoelastic Fluids, J. M. Rodriguez, Gary Kent Patterson, J. L. Zakin

Symposia on Turbulence in Liquids

The response of a hot-film wedge probe in viscoelastic fluids has been investigated by imposing on the probe a sinusoidal vibration of known amplitude and frequency. Root-mean-square (rms) velocities calculated from the displacement of the probe were compared to rms velocities obtained with a constant temperature anemometer. The tests were performed under turbulent flow conditions and also at flow rates where viscoelastic effects (i.e., decrease of heat transfer rates from the probe to the fluid and drag reduction) were observed.

The frequency range covered was narrow ( < 100 cps). This limitation was imposed by the decision to superimpose the sinusoidal vibrations on the turbulence signal, in order to have dynamic conditions similar to those encountered in actual turbulence measurements. Measurements were performed in mineral oil and four solutions of polyisobutylene (Vistanex L-200) In mineral oil.

The experimental technique was established by measuring the response of the probe in …

Some Aspects Of Flow Through Rotating Circular Tubes, D. L. Boyer, J. R. Guala

Symposia on Turbulence in Liquids

The flow of water in a circular tube rotating about an axis perpendicular to the axis of the tube is studied. Information about the flow is obtained from coated hot-film probes and a constant temperature anemometer. A maximum Reynold's number of 9,500 is obtained and the Taylor number is varied from 800 to 3,100. Little similarity is found to exist between flows in rotating and in non-rotating systems in this range of parameters.

Measurements Of Turbulence Characteristics In Water And In Dilute Polymer Solutions, Tadeusz Kowalski

Symposia on Turbulence in Liquids

Measurements of turbulence characteristics were made inside a boundary layer in external flow of water and in water with polymer additives of the Polyox type. Flush mounted hot-film sensors and wedge, parabolic, and cylindrical sensors were used to measure the turbulent velocity fluctuations. Graphs are given of energy density, dissipation, turbulence shear correlation spectra, and microscale of turbulence distribution. Tests were run in an open channel flow at one Reynolds number and two rates of polymer injection to give 20 and 40 ppm average concentration in the boundary layer. The results indicate that the advent of the quartz insulated hot-film …

Industrial Arts Research Methods, Clinton E. Langstraat

Graduate Research Papers

This report has been compiled as one of the culminating activities of 33:292 Industrial Arts Research Methods. This paper can be considered as a written record of the students' and instructor's efforts in establishing further guidelines for work in 33:270, and related activities. Consequently, the report is not highly technical in nature and the number of citations is considerably less than may be found in a typical report written for graduate credit.

However, it is the opinion of the writer that some valuable information has been recorded and it is his hope that some future graduate student may find it …

Engineering Geognosy Of Boyd County, Tommy C. Hopkins, Jerry G. Pigman

Kentucky Transportation Center Research Report

Engineering soils and geologic maps are proving to be invaluable tools of engineers, industrial leaders, community planners, and administrators during tbe preliminary stages of planning and site selection for major construction projects and the development of plans to use nature's basic resource--the land. Quantitative engineering data for soils and geological formations, and the interpretation of tbese data, are important factors to consider in the best land-use plans and in providing stable foundations and proper usage of earth materials for highways, buildings, and other earth structures. Engineering soils and geologic maps can be used to great advantage by planners and engineers …

A Preliminary Evaluation Of Mounds To Divert Wayward Vehicles Away From Rigid Obstructions, Gordon R. Garner, J. B. Venable

Kentucky Transportation Center Research Report

In the summer of 1965, the first fatality report involving an interstate median bridge pier in Kentucky caused concern among state and national officials for the safety of motorists who perchance or otherwise enter upon a collision course toward an unprotected bridge pier. A consensus of opinion seemed to indicate that some form of attenuation or deflection device was necessary.

Early innovations employed various short guardrail configurations to deflect wayward vehicles from the piers. The use of small, short sections has since evolved until present methods include surrounding the bridge pier with several hundred feet of guardrail, including ramped-end treatment …

Cold-Rolled Austenitic Stainless Steel: Materials Properties And Structural Performance, George Winter, S. T. Wang

CCFSS Library (1939 - present)

The cold reduction in thickness of austenitic stainless steel sheet brings about the following significant characteristics of material properties: 1) higher strength with an increasing amount of cold working, 2) more pronounced anisotropic material properties with increasing cold working, 3) stress strain relations different in tension and compression and depending on directions, and 4) nonlinear stress strain curves with relatively low elastic limits, especially in longitudinal compression. In addition, local buckling is encountered in thin walled structural members. These are the problems associated with the structural design of stainless steel members. The purpose of this investigation is to develop the …

A Noise Figure Lower Bound And A Frequency Converter, Grant Myers

Department of Electrical and Computer Engineering: Faculty Publications

This article establishes a lower bound for the noise figure of two networks in cascade. This is illustrated by means of a passive low-level frequency converter which utilizes a back diode as a nonlinear conductance. Other investigators have analyzed the properties of low-level frequency converters. However, the greatest lower bound of a combination of the converter and intermediate frequency amplifier system was not considered previously and is the subject of this paper. Knowledge of this lower bound has practical significance because if a measured value of noise figure is less than this lower bound, it follows that the measurement is …

Use Of A Tungsten Filament Lamp As A Pirani Gauge For Continuous Gas Analysis, Donald S. Remer, Fredrick H. Shair

All HMC Faculty Publications and Research

Reported herein is a thermal conductivity technique by which continuous and quantitative data have been obtained in a cataphoretic system without sample withdrawal.

Chemistry Of The Oxidant, Ferrate, Its Interaction With Specific Organics Found In Waste Water, Donald H. Williams, J. T. Riley

KWRRI Research Reports

It became obvious during this investigation that while much work has been done with ferrate (VI) chemistry, discrepancies existed in the literature and very little attention had been given possible engineering uses. This work attempted to fulfill these two needs in an exploratory manner.

The preparative techniques were reviewed and mechanical improvements made in one which allowed improved yields. Essentially what was done was to enlarge and improve the filtering technique of the product and use cooler temperatures throughout the preparation. This greatly shortened the time required. Then it was learned that the addition of ethyl alcohol to the final …

Diffusion Coefficients Of D-Glucose In Aqueous Carboxymethylcellulose And Carboxypolymethylene Solutions, A. L. Huang, S. V. Desai, Robert M. Wellek

Chemical and Biochemical Engineering Faculty Research & Creative Works

A micro interferometric method was used to determine pseudo-binary, molecular diffusion coefficients for diffusion of D-glucose in aqueous carboxymethylcellulose (CMC) and aqueous carboxypolymethylene (Carbopol) solutions. An initial solute concentration of about 9 wt. % D-glucose in the aqueous polymer solutions was used. The polymer concentrations for the CMC solutions ranged from 1.2 to 2.2 wt. % and for the Carbopol solutions from 0.18 to 0.28 wt. %. Diffusion coefficients were determined as a function of reduced solute concentration, both with and without the effect of solution volume change during diffusion being considered. © 1969, American Chemical Society. All rights reserved.

Test 1017: Allis-Chalmers 220 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

Explanation of Test Report Preparation for Performance Runs Belt or Power Take-off Performance Maximum Power and Fuel Consumption Varying Power and Fuel Consumption Drawbar Performance Varying Power and Fuel Comsumption Maximum Power with Ballast Maximum Pull without Ballast Varying Power and Travel Speed with Ballast

The 1966 Eruption Of Izalco Volcano, El Salvador, William I. Rose, Richard E. Stoiber

Department of Geological and Mining Engineering and Sciences Publications

During October–November 1966 900,000 m³ of olivine basalt flowed from the flank of Izalco volcano, El Salvador. The total heat energy was approximately 10¹⁵ calories. No measurable changes in gravity occurred at stations on the active cone between August 1964 and August 1967. In the summit crater fumaroles have surface temperatures as high as 540°C. The cooling rate of these fumaroles was 18°C/yr before the eruption and 45°C/yr after. Yearly temperature cycles due to wet and dry seasons are superimposed on the general cooling trend. The rate of gas emission at four fumaroles in November 1967 was 86 …