Engineering Commons^™

Design Considerations For A Laser Doppler Velocimeter, Leroy M. Fingerson

Symposia on Turbulence in Liquids

In optimizing an instrument design, it is important to differentiate between the theoretical limitations of the technique and apparent limitations that can be reduced or eliminated by design. In the laser-Doppler anemometer, the theoretical limits are associated with the fact that particle velocity is the measurement rather than fluid velocity. The accuracy and speed of the particle velocity measurements do not appear to have theoretical limitations. Therefore, instrument design must concentrate on improving the measurement of particle velocity.

A complete system has been designed to optimize accuracy, speed, convenience, and flexibility in measuring particle velocity. The problems inherent in transferring …

Turbulence Measurements With A Sampling Laser-Doppler Velocimeter, P. D. Iten

Symposia on Turbulence in Liquids

A novel sampling signal processor overcomes the difficulties encountered with frequency trackers in the investigation of unseeded highly turbulent flows. This sampling system consists essentially of a swept filter, e.g. a standard RF-spectrum analyzer, a digital data memory and a storage oscilloscope. It is able to determine first-order statistical averages of turbulent flows with high fluctuation frequencies and amplitudes even at very low scattering particle concentrations. Since the velocity samples are not statistically independent of the velocity, the sampled velocity data has to be corrected in order to obtain unbiased statistical averages. A theoretical analysis and experimental investigations of the …

Phase Separation In Turbulent Two-Phase Flow, Francois J. Resch, Hans J. Leutheusser

Symposia on Turbulence in Liquids

The paper is based on an experimental study of a typical instance of bubbly two-phase flow, viz. the air-entraining roller zone of hydraulic jumps in open channels. The investigation was undertaken with the aid of hot-film anemometry techniques involving instant digitization of analog signals, and delayed electronic processing of the tape-recorded data. Special computer programs were designed to separate the two phases according to a well-defined signal threshold. It is this aspect of the work which is being dealt with in the paper.

Turbulent Characteristics Of Two-Phase, Gas-Liquid Stratified Channel Flow, D. M. Johns, T. G. Theofanous, R. N. Houze

Symposia on Turbulence in Liquids

The turbulence characteristics of the bulk phases were studied in a stratified, two-dimensional, gas- liquid channel flow. Initial results are presented comparing mean velocity and turbulent intensity profiles with those obtained in a prior study at the same bulk phase Reynolds numbers. The results indicate that comparison of two realizations of stratified gas- liquid flow cannot be adequately done on the basis of bulk-phase Reynolds numbers. Comparisons must be based on some more fundamental relationships involving the gas-liquid interactions.

Conditioned Sampling Techniques, R. E. Kaplan

Symposia on Turbulence in Liquids

The concept of organized, spatially coherent large scale structures has been investigated for a variety of turbulent shear flows by a technique called "Conditional Sampling." It can be shown that these structures are related to physically important activities such as, 1) the entrainment of turbulent boundary layers, and 2) the maintenance of turbulence by a wall, 3) the growth of free shear layers, and 4) the structure and noise production of turbulent jets.

The general technique of conditioned sampling is related to visualizations of the flow, and to problems of synchronization of images in the presence of noise. While there …

Experiments On The Structure Of Turbulence In Fully Developed Pipe Flow, T. R. Heidrick, S. Banerjee, R. S. Azad

Symposia on Turbulence in Liquids

This paper describes a series of two-point measurements in fully developed pipe flow. Measurements of the phase shifts between the Fourier components of the axial velocity fluctuations at two points were made with three different orientations of the two points. In all cases the two points were close enough together that the turbulent structure remained essentially "frozen" while passing between the sensors. The phase velocities, C₁(f), and inclinations, α(f) (defined previously by Heidrick et al. (8)), of each frequency component, f, were determined from these measurements.

In general, the Fourier components are inclined to the wall - the …

Experimental Measurement Of Particle Dispersion In Turbulent Flow, N. M. Howard, C. C. Meek, B. G. Jones

Symposia on Turbulence in Liquids

The dispersion of particles in turbulent flows, phenomena such as dispersion, diffusion, and sedimentation, and a more fundamental point of view, the description of particle interaction with the turbulent field are recently of increasing interest. A system capable of investigating statistical structure of the motion of particles in a turbulent fluid flow using a turbulent water pipe flow system and particles tagged with C0-60 radioactive pellets has been constructed and tested. The particles were followed in their trajectory by a group of detectors consisting of NaI(Tℓ) crystals mounted on photomultiplier tubes which move with the particles on a movable carriage. …

A Comparison And Analysis Of Detection Methods For The Measurement Of Production In A Boundary Layer, G. R. Offen, S. J. Kline

Symposia on Turbulence in Liquids

Two hot films and dye visualizations have been employed, simultaneously, in a turbulent boundary layer to explore the relations among visual observations and five kinds of detection methods using conditional sampling. The results show that all methods correlate positively with each other, but not with high enough values of correlation coefficients to indicate true correspondence between any two thus far studied. Moreover, none of the detection methods devised to date indicate a plateau in number of events as a function of trigger threshold.

The results also provide additional information on several other matters: (i) the relationship of outward motions from …

An Experimental And Theoretical Study Of The Viscous Sublayer For Turbulent Tube Flow, Lindon C. Thomas, H. L. Greene

Symposia on Turbulence in Liquids

Flush-mounted anemometer probes have been used to further study characteristics of the viscous sublayer for both Newtonian and drag reducing solutions, with particular emphasis given to low Reynolds number turbulent tube flow. Experimental measurements for the mean frequency of bursting or renewal within the wall region are compared with theoretical predictions obtained on the basis of the surface renewal and penetration model.

Both theory and experiment taken together suggest that the effect of the mean axial pressure gradient on the viscous sublayer becomes important for the deeper molecular penetration associated with low Reynolds number flow. Also, a pronounced lessening of …

On The Interpretation Of The Output Of Hot-Film Anemometers And A Scheme Of Dynamic Compensation For Water Temperature Variation, J. Tan-Atichat, H. M. Nagib, J. W. Pluister

Symposia on Turbulence in Liquids

Using a special calibration tunnel developed during the course of this study, the static and dynamic response of several kinds of commercially available hot-film probes with single and multiple sensors of the cylindrical-fiber type are examined. The effects of different parameters, including those of the anemometer bridge, on the output and performance of the probes are evaluated. In particular, the consequences of variations in water temperature on the hot-film anemometer output are determined. The results reveal a large effect of the water temperature on the calibration curves (in an extreme case a change in temperature of only 5.5°F can result …

Use Of The Split-Film Sensor To Measure Turbulence In Water Near A Wall, Paul H. Blinco, V. A. Sandborn

Symposia on Turbulence in Liquids

Because of its small size and unique design, the 0.15-mm diameter split-film sensor has many significant advantages over the conventional X-configuration hot-film sensor and the yaw-wire technique for measuring turbulence near a wall. Calibration of the split- film sensor indicates that the magnitude and yaw angle of the instantaneous velocity vector is dependent only on the sum and ratio of the sensor outputs, respectively. Results of limited measurements of the longitudinal and vertical turbulence intensities and Reynolds stress for hydraulically smooth, free surface flows are presented. Digital time series of the split-film outputs revealed the following information: (1) the split-film …

Author Index, University Of Missouri--Rolla

Symposia on Turbulence in Liquids

No abstract provided.

Measurements Of Pulsating Turbulent Water Flow In A Tube, S.-Z. Lu, R. J. Nunge, F. F. Erian, M. Mohajery

Symposia on Turbulence in Liquids

The experimental method associated with obtaining meaningful information from the hot-film anemometer signals in fully developed pulsating turbulent flow where the pulsations are sinusoidal in time is discussed. The results of a number of experiments in water reveal the nature of the longtime and short-time average velocity and pressure. Velocity measurements between 0.95 radii and the centerline demonstrate that the long-time average velocity distribution is coincident with that for steady turbulent flow at the same Reynolds number. Also, no significant differences between the longtime average axial pressure drop in the pulsating and steady flows were noted, although this requires further …

Intermittency And Structure Of A Jet Exhausting Into A Stratified Fluid, Alan Brandt, H. E. Gilreath, C. L. Yates, C. R. Walton

Symposia on Turbulence in Liquids

This preliminary study of the mechanism by which local turbulent regions generate internal gravity waves in a stably stratified fluid is based on comparisons of the visual and hot-film- anemometer observations of a jet exhausting into a stratified fluid with those for a jet exhausting into a homogeneous medium. The stratified environment limits the growth of the mean jet boundary, or from another point of view, inhibits the vertical motion of the instantaneous turbulent/non-turbulent interface. The visual and non-conditional statistical averages agree with expectations and with previous measurements in stratified turbulent wakes. Application of a standard criterion to determine the …

Promising Directions For Liquid Turbulence Research --Panel Discussion, Victor Goldschmidt, J. H. Whitelaw, V. A. Sandborn, Val Kibens, R. E. Kaplan

Symposia on Turbulence in Liquids

No abstract provided.

Test 1131: Deutz D 4506 And 4507 Diesel (Also Deutz-Fahr D-4507 Diesel) 8-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF TEST REPORT

GENERAL CONDITIONS

East tractor is a production model equipped for common usage. Power consuming accessories can be disconnected only when it is convenient for the operator to do so in practice. Additional weight can be added as ballast if the manufacturer regularly supplies it for sale. The static tire loads and the inflation pressures muse conform to recommendations in the Tire Standards published by the Society of Automotive Engineers.

PREPARATION FOR PERFORMANCE RUNS

The engine crank case is drained and refilled with a measured amount of new oil conforming to specifications in the operator’s manual. The …

Test 1138: David Brown 1212 Diesel (Also Case 1210 Power Shift Diesel) 12-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF TEST REPORT GENERAL CONDITIONS East tractor is a production model equipped for common usage. Power consuming accessories can be disconnected only when it is convenient for the operator to do so in practice. Additional weight can be added as ballast if the manufacturer regularly supplies it for sale. The static tire loads and the inflation pressures muse conform to recommendations in the Tire Standards published by the Society of Automotive Engineers. PREPARATION FOR PERFORMANCE RUNS The engine crank case is drained and refilled with a measured amount of new oil conforming to specifications in the operator’s manual. The …

Test 1148: Case 1370 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF TEST REPORT GENERAL CONDITIONS East tractor is a production model equipped for common usage. Power consuming accessories can be disconnected only when it is convenient for the operator to do so in practice. Additional weight can be added as ballast if the manufacturer regularly supplies it for sale. The static tire loads and the inflation pressures muse conform to recommendations in the Tire Standards published by the Society of Automotive Engineers. PREPARATION FOR PERFORMANCE RUNS The engine crank case is drained and refilled with a measured amount of new oil conforming to specifications in the operator’s manual. The …

Tests On Field Welded Puddle And Fillet Weld Connections, R. S. Yarnell, Teoman Peköz

CCFSS Library (1939 - present)

INTRODUCTION This report contains the results of tests on 122 field welded connections. Most of the specimens are approximately the same as those that were shop welded previously and tested. The results of tests on shop welded specimens are given in Ref. 2. Those field welded specimens that do not correspond to the shop welded specimens are indicated in Table lA. Except as noted, all notations, variables, weld configurations and procedures are identical with those in Ref. 2. All specimens were tested in a hydraulic test machine under monotonically increasing slowly applied tensile force. This report differs from Ref. 2 …

Diaphragm Braced Thin-Walled Open Sections And Design Of Wall Studs, Amir Simaan, Teoman Peköz

CCFSS Library (1939 - present)

INTRODUCTION Cold-formed steel wall studs generally are I, Z or channel shaped with or without stiffening lips, and with webs perpendicular to the plane of the wall. Because of their configuration and dimensions, these sections are quite unstable by themselves. However, the stability and, hence, load-carrying capacity of such studs are increased substantially once they are connected to the wallboard material. The main function of the wallboard is that of enclosure, but it serves also as a bracing system for the studs. Gypsum board, vegetable fiberboard, tempered board or plywood are commonly used wallboard materials. Such boards are connected to …

Column Research Council: Proceedings 1973, Column Research Council

CCFSS Library (1939 - present)

One of the purposes of the Council is to maintain a forum where problems related to the design and behavior of columns and other compression elements in metal structures can be presented for evaluation and discussion. The Annual Technical Session provides opportunity to carry out this function. The 1973 Annual Technical Session was held on May 2 and 3 at the Los Angeles Hilton Hotel in Los Angeles, California. Sixty persons attended the Session and thirty-three papers were delivered. A panel discussion on "Frame Stability Under Seismic Loading" was held in the evening of May 2, 1973. Panelists were E. …

Conference Proceedings Of The 3rd Biennial Symposium On Turbulence In Liquids, University Of Missouri--Rolla

Symposia on Turbulence in Liquids

The Third Biennial Symposium on Turbulence in Liquids showed further progress in the investigator's ability to measure turbulence parameters and in the general understanding of turbulence. The most impressive advances in measurement seemed to be the ability to measure deeper into the turbulent boundary layer in order to obtain profiles over the entire turbulence production region and the rapid development of conditioned-sampling techniques for studying hypotheses for mechanisms.

Dynamic Response Of Forced Convective Heat Transfer From Cylinders To Low Prandtl Number Fluids, D. G. Malcolm, V. Verma

Symposia on Turbulence in Liquids

The present paper can be viewed as an extension of the work of Lim and Sleicher (9). They evaluated the frequency response of the heated element submerged in liquid metal by a perturbation method for Peclet numbers of up to 0.4. Velocity fluctuations were assumed small and second-order perturbations neglected. The Oseen approximation was made to the velocity field. Here the velocity configuration has been approximated to that of potential flow and the convection equation has been solved numerically with the aid of a digital computer. The potential flow approximation, as compared with the Oseen approximation, is reasonable over a …

The Economic Efficiency Of Inter-Basin Agricultural Water Transfers In Utah: A Mathematical Programming Approach, John E. Keith, Jay C. Andersen, Calvin G. Clyde

Reports

The economic efficiency of water development in Utah, including transfer systems, has seldom been examined, not has the costs of public policies which result in deviations from efficient allocations. In order that public officials be better informed about water allocations, the present effort examines the efficient allocation of water in time frames up to 2020 under several alternative assumtions and calculates that cost of alternative policies. Using mathematical programming techniques, a computer model is developed to determine the supply (marginal cost) and demand (value or marginal product) relationships for agricultural water, given depletions for municipal and industrial (M&I) and wetland …

A Water Resource Management Model, Upper Jordan River Drainage, Utah, Bi-Huei Wang, James I. Felix, Rick L. Gold, Craig T. Jones, J. Paul Riley

Reports

As demands upon available water supplies increase within a river basin, there is an accompanying increase in the need to assess the downstream consequences resulting from changes at specific locations within the hydrologic system. This problem is approached in this study by digital computer simulation of the hydrologic system. Modeling concepts are based upon basic relationships which describe the various hydrologic processes. Within a hydrologic system these relationships are linked by the continuity-of-mass principle which requires a mass balance at all points. Spatial resolution is achieved by considering the modeled area as a series of subbasins. The time increment adopted …

Effects Of Baffles On The Performance Of Anerobic Waste Stabilization Ponds, Stephen B. Nielson, E. Joe Middlebrooks, Donald B. Porcella

Reports

The performance of three baffled model ponds was monitored and compared to the performance of an unbaffled model pond utilizing four hydraulic and organic loading rates. All four ponds were operated simultaneously under the same environmental conditions using a synthetic wastewater.

Removal of organic carbon by the biological system in the different pond configurations only varied from 94-98 percent at the longest detention time (15 days); however, a considerable effect of the baffling was observed at the lower detention times. At a hydraulic detention time of 1.5 days the percent carbon removal was 53, 60, 62, and 70 percent for …

Legendre Coefficients For Series Solution Of The Orientation Distribution Function For Ellipsoidal Macromolecules In Two-Dimensional Laminar Flow, Myrne R. Riley

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The double refraction and viscosity of a suspension of asymmetrical colloidal particles subject to continuous laminar flow vary with the orientation distribution of the suspended particles produced by the shearing field and Brownian motion. Recursion formulas are developed for the Legendre coefficients of the series solution of the orientation distribution function for a suspension subject to two-dimensional laminar flow, thus, extending the works of Peterlin, Wayland, and Scheraga. © 1973.

Test 1136: David Brown 995 Diesel (Also Case 995 Diesel) 12-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF TEST REPORT GENERAL CONDITIONS East tractor is a production model equipped for common usage. Power consuming accessories can be disconnected only when it is convenient for the operator to do so in practice. Additional weight can be added as ballast if the manufacturer regularly supplies it for sale. The static tire loads and the inflation pressures muse conform to recommendations in the Tire Standards published by the Society of Automotive Engineers. PREPARATION FOR PERFORMANCE RUNS The engine crank case is drained and refilled with a measured amount of new oil conforming to specifications in the operator’s manual. The …

De Los Sealabs A Los Skylabs, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

¿Respiraremos Algún Día El Agua Del Mar?, Javier Gimeno, Aldemaro Romero Jr.

Publications and Research

No abstract provided.