Chemical 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 …

Optimization Of An Lda System, Robert Smid

Symposia on Turbulence in Liquids

This paper discusses the various considerations leading to the optimization of a laser Doppler anemometer for measurements in the flows of gases, liquids, and solids. The requirements placed on the various parameters of the optics by the experiment are discussed in general for different modes of operation. Expressions determining these optical parameters in certain instances given by various authorities are presented and compared. This includes such topics as: laser power, particle size, measuring volume size, optical variation in transmitting and receiving optics, and photodetector selection.

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.

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. …

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 …

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 …

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 …

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 …

Convergence Of Material Balance In Mathematical Simulation Of Petroleum Reservoirs, Abdul Rashid Merchant

Doctoral Dissertations

One criterion for determining the precision of pressures calculated by a simulation model is the accuracy of the material balance. A high degree of precision in the calculated pressures is a necessary condition for elimination of error in prediction of fluid migration in the reservoir. However, this condition is not sufficient to guarantee accuracy of the simulation, since inaccuracies are introduced by truncation errors, machine round-off errors, and by the use of finite difference approximations to represent nonlinear partial differential equations.

A new procedure called Error Matrix Technique has been developed for reduction of material balance errors. This reduction is …

Film Boiling Of Freon 113, Normal Pentane, Cyclopentane, And Benzene From Cylindrical Surfaces At Moderate Pressures, Gary Joseph Capone

Doctoral Dissertations

"An investigation of film boiling heat transfer in saturated pools of liquid Freon 113, Normal Pentane, Cyclopentane, and Benzene was made. The fluids were boiled from copper, cylindrical heat transfer surfaces, 3 inches long, and 0.55, 0.75, and 1.00 inch in diameter. The heat transfer elements were positioned horizontally in an autoclave and tested at moderate pressures of up to a pressure of 242.5 psia for Normal Pentane.

The experimental data are discussed and compared with known film boiling correlations. The known correlations were found to be inadequate in predicting heat transfer coefficients as a function of pressure, temperature difference …

Film Boiling Of Benzene, Freon 113, Freon 11, And Normal Pentane From Horizontal Surfaces At Atmospheric Pressure, Richard Stanley Kistler

Doctoral Dissertations

"A film boiling study was conducted with five different area flat plates at atmospheric pressure for benzene, Freon 113, Freon 11, and n-pentane. The heat transfer surface was horizontal for all tests.

The data were compared to the correlations commonly used for heat transfer. The common correlations were found to be in error for small surface sizes, but adequate for all fluids except benzene for the largest surface, a semi-empirical equation which correlates the available data as a function of surface diameter was derived and discussed"--Abstract, page iii.

Measurement Of Molecular Diffusivities Of Liquid Alkane Systems, James W. Moore

Doctoral Dissertations

"An unsteady-state porous frit method of diffusion coefficient measurement, recently developed in this laboratory, was improved and expanded upon. The experimental technique has been refined and documented. The unsteady-state diffusion of an initially 0.5 N NaCl solution into pure water (effective diffusivity -1.480 x 10^-5 cm²/sec) was employed as the calibration standard. An overall calibration precision of ±4% was obtained. Diffusion times of two hours or less were used for the non-aqueous diffusivity measurements. The validity of this measurement technique was confirmed by the agreement of the measured self-diffusion coefficient of n-heptane (25⁰C) with literature values.

A …

A Study Of Homogeneous Catalysis By High-Pressure Kinetics. The Mechanism Of Catalysis Of A Diels—Alder Reaction, Bruce E. Poling, Charles A. Eckert

Chemical and Biochemical Engineering Faculty Research & Creative Works

The application of high-pressure kinetics as a tool to investigate the detailed mechanism of catalysis of a reaction is demonstrated. Activation volumes have been determined for the Diels-Alder addition of 2, 3-dimethylbutadiene to n-butyl acrylate, both uncatalyzed and catalyzed with AICI3. Also, partial molal volumes of reactants and products have been measured. From these data it is shown that the volume profile along the reaction coordinate is similar for both the catalyzed and uncatalyzed reactions. Further, both reactions proceed by a concerted one-step mechanism through a compact transition state with maximum accumulation of double bonds. Thus, the role of the …

Drag Reduction On Non-Ionic Surfactants In Aqueous Systems, Jen-Lin Chang

Masters Theses

"The use of polyoxyethylene alcohol non-ionic surfactants as drag reducing additives in aqueous systems was investigated. Significant drag reduction was obtained with suitable combinations of one percent Alfonic 1214 and salts at 30°C such that the surfactant was near or above its upper critical solubility temperature. Maximum drag reduction was observed at the cloud point. Relative viscosity values also peaked at this point. No upper critical shear stress was attained up to wall shear stresses of 2,000 dynes/cm² with one percent Alfonic 1214 solutions at their cloud points.

At a fixed temperature, the salt concentration required to reach the …

Synthesis And Characterization Of Poly-(P-Phenylene Pyromellitamic Acid), Constantine William Tsimpris

Doctoral Dissertations

"Poly-(p-phenylenepyromellitamic acid)s have been synthesized over the weight average molecular weight range from 8,000 to 22,000 by reaction of pyromellitic dianhydride and p-phenylenediamine in dimethylformamide. The polymers were recovered as amorphous yellow powders having planar dimensions of 3-4 x 1-2 µm with thicknesses of 0.1-0.2 µm and contained 20-30% associated dimethylformamide. Consumption of reactants and attainment of the ultimate molecular weight of the polymer was found to occur within one minute. Thermogravimetry of the solid poly(amic acid)s was used in a method developed to determine the amount of associated dimethylformamide, to study the cyclization of poly(amic acid) to polyimide, and …

Mass Transfer With Second-Order Chemical Reaction Inside Circulating Fluid Droplets, Roy James Brunson

Doctoral Dissertations

"The solution of a mathematical model is presented which describes mass transfer accompanied by a second-order chemical reaction inside a circulating, fluid sphere for the laminar flow region. The values for eight different mass transfer indices are presented as a function of the Peclet number, reaction number, diffusivity ratio, concentration ratio, and the dimensionless contact time. The results of this work are compared with the film and penetration theories for mass transfer with reaction as modified to apply inside a fluid sphere. This work corrects the three factors which limit the accuracy of applying previous theories to fluid spheres: geometrical …

A Study Of Three Methods Which Solve A Suboptimum Control Problem On An Iterative Analog Computer, Joseph Camp Finney

Masters Theses

"Three methods for optimizing a proportional and a proportional-integral controller parameter problem were investigated on an iterative analog computer. The three methods were the parameter-perturbation correlation method, the absolute biasing method, and the variable step size method. The process controlled was third order linear. The performance function used to judge the quality of the controller was the time integral of the absolute value of error. All three methods required a trial and error adjustment of the parameters used in these methods. The optimum solution was obtained by all methods. The absolute biasing method, for both the proportional and the proportional-integral …

The Electrochemical Reduction Of Fumaric Acid On Hg-Bi Cathodes, Chen Hwei Chi

Doctoral Dissertations

"The electrochemical reduction of fumaric acid was studied on Hg, Hg/1%Bi amalgam, and Bi at 60ºC in acidic solutions of various pH ranging from 0.3 to 3.7. The fumaric acid was reduced to succinic acid with high efficiency on each electrode. The steady state kinetic parameters included Tafel slopes of ca. 2.3 RT/F and first order concentration dependences for both undissociated fumaric acid and H⁺. Transient measurements indicated low coverages of adsorbed fumaric acid and no adsorbed hydrogen species in the potential region of the reaction. A reaction mechanism is proposed which involves a chemical rate determining step between an …

Kinetic Analysis Of The Radiation Polymerization Of Methyl Methacrylate–Kaolin Clay Composites, J. J. Beeson, Kenneth G. Mayhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

In the first of a two‐part series, a kinetic study has been made on the effects of gamma rays (60Co) in air and inert gas on the polymerization of a 50:50 weight‐mixture methyl methacrylate (MMA)–kaolin clay system. The effect of dose rate (7.35–24.9 rads/sec), temperature (25° to 75°C), and total dose on the percentage conversion of monomer to polymer was studied. The rate of formation of polymer at 25°C in the composite system was found to be faster when compared to a bulk MMA system at the same dose rate. This acceleration showed that the clay had a catalytic effect …

Entrance Effects On Capillary Degradation Of Dilute Polystyrene Solutions, J. D. Culter, Kenneth G. Mayhan, Gary Kent Patterson, A. A. Sarmasti, J. (Jacques) L. Zakin

Chemical and Biochemical Engineering Faculty Research & Creative Works

No abstract provided.

Discussion, A. G. Fabula, Gary Kent Patterson

Chemical and Biochemical Engineering Faculty Research & Creative Works

No abstract provided.

The Plasma Polymerization Of Vinyl Monomers. I. The Design, Construction, And Operation Of An Inductively Coupled Plasma Generator And Preliminary Studies With Nine Monomers, L. F. Thompson, Kenneth G. Mayhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

An apparatus was constructed which would allow vinyl‐type monomers (and others) to polymerize at ambient temperatures in the presence of an inductively coupled RF field. The details of the construction of the system are reported along with preliminary results obtained from nine monomers: styrene, methylvinyldichlorosilane, vinyl acetate, acrylonitrile, vinyl fluoride, 1,1‐difluoroethylene, vinyl chloride, ethylene, and 1,3‐butadiene. Copyright © 1972 John Wiley & Sons, Inc.

Characterization Of Poly(Methyl Methacrylate) From Radiation‐Induced Polymerization In The Presence Of A Kaolin Clay Substrate, J. J. Beeson, Kenneth G. Mayhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Two types of polymer are formed in the radiation‐initiated polymerization of methyl methacrylate (MMA)–kaolin clay complexes. Homopolymer can be extracted from the complex by the use of organic solvents. Inserted polymer must be removed by dissolution of the polymer–clay complex with hydrofluoric acid. The polymers formed show no differences in structure (as determined by infrared analysis), had high molecular weights (1–5 x 106), and had similar molecular weight distributions (as determined by GPC). The molecular weights of the homopolymer increased as temperature increased (25°–75°C), and dose rate decreased (24.9–7.35 rads/sec). The isotacticity of the polymers when compared to irradiated bulk …

Saturated Enthalpies For Mixtures Of Propane And Propene, David B. Manley, George W. Swift

Chemical and Biochemical Engineering Faculty Research & Creative Works

No abstract provided.

The Plasma Polymerization Of Vinyl Monomers. Ii. A Detailed Study Of The Plasma Polymerization Of Styrene, L. F. Thompson, Kenneth G. Mayhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

A study has been made on the plasma polymerization of styrene monomer in a cold, low‐power, inductively coupled RF plasma. Styrene monomer yielded an insoluble, crosslinked film which was slightly colored. A kinetic study is reported for styrene. The effects of power level, bleed rate of monomer, pressure, and reactor geometry on the rate of polymer formation are reported. A mechanism is postulated for plasma polymerization. It was found that the initiation step was the rate controlling step and that the reaction followed a cationic polymerization scheme. Both crosslinking and discoloration of the polymers occur at the time of polymerization …

Preliminary Studies With A Variable Transfer Composite Polymer Membrane., Samuel Walter Dortch

Masters Theses

"A preliminary study was done to determine the feasibility of using a compressed fibrous teflon (PTFE) silicone polymer membrane in extracorporeal oxygenation devices. A series of composite membranes were fabricated, using different concentrations of a dimethyl silicone polymer dissolved in petroleum ether, to give membranes having variable oxygen transfer properties. A gas-gas system was chosen to obtain the necessary transfer data. Data were obtained by transferring pure oxygen through the membranes into a mixture of 47 mole percent oxygen and 53 mole percent carbon dioxide. All analyses were obtained by chromatographic techniques. The results of these experiments show that membranes …

High Pressure Water Jet Cutting Of Rock, Richard Lee Henry

Masters Theses

"Three experiments are described that investigate the impingement of high pressure water jets on rock. The effect of jet pressure, stand-off distance, and time of impact on penetration and specific energy of rock removal are determined on Berea sandstone, Georgia marble, and Missouri granite. Pressures range from 5,000 psi to 25,000 psi, stand-off distances from 2.0 inches to 4.0 inches and time from 0.1 seconds to 5.0 seconds. The nozzle diameter used was 0.023 inches. The effect of nozzle speed and number of passes over the same area on depth of cut and specific energy are investigated on the above …

Front Matter, University Of Missouri--Rolla

Symposia on Turbulence in Liquids

No abstract provided.

Current Investigations Of Turbulent Shear, S. J. Kline, G. R. Offen, W. C. Reynolds

Symposia on Turbulence in Liquids

The paper covers first a short review of the history of research on turbulent shear and second a description of current experiments which may lead to further understanding.

The first portion categorizes the kinds of data which have been taken and discusses what can be learned from each. It then summarizes what is firmly established concerning the nature of turbulent shear, mostly from work of the past decade. A description of the several interpretations of these data under theoretic study by current leading researchers is then given.

The second portion of the paper discusses the extraordinarily difficult problem of identifying …