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Introductory Lectures On Turbulence: Physics, Mathematics And Modeling, James M. Mcdonough

Mechanical Engineering Textbook Gallery

From Chapter 1:

The understanding of turbulent behavior in flowing fluids is one of the most intriguing, frustrating— and important—problems in all of classical physics.

The problem of turbulence has been studied by many of the greatest physicists and engineers of the 19th and 20th Centuries, and yet we do not understand in complete detail how or why turbulence occurs, nor can we predict turbulent behavior with any degree of reliability, even in very simple (from an engineering perspective) flow situations. Thus, study of turbulence is motivated both by its inherent intellectual challenge and by the practical utility of a …

Capacitance Metrology Of Curved Surfaces: Study And Characterization Of A Novel Probe Design, Philip T. Smith Jr.

University of Kentucky Doctoral Dissertations

Capacitive sensors are frequently applied to curved target surfaces for precision displacement measurements. In most cases, these sensors have not been recalibrated to take the curvature of the target into consideration. This recalibration becomes more critical as the target surface becomes smaller in comparison to the sensor. Calibration data are presented for a variety of capacitance probe sizes with widely varying geometries. One target surface particularly difficult to characterize is the inner surface of small holes, less than one millimeter in diameter. Although contact probes can successfully measure the inner surface of a hole, these probes are often fragile and …

Characterization And Flow Physics Of Plasma Synthetic Jet Actuators, Arvind Santhanakrishnan

University of Kentucky Doctoral Dissertations

Plasma synthetic jet actuators are investigated experimentally, in which the geometrical design of single dielectric barrier discharge (SDBD) plasma actuators is modified to produce zero-mass flux jets similar to those created by mechanical devices. The SDBD plasma actuator consists of two rectangular electrodes oriented asymmetrically and separated by a layer of dielectric material. Under an input of high voltage, high frequency AC or pulsed DC, a region of plasma is created in the interfacial air gap on account of electrical breakdown of the ambient air. A coupling between the electric field in the plasma and the neutral air near the …

Systems And Methods For Inspecting Coatings, Kozo Saito, Mohammed I. Hassan Ali, Akira Numasato, Mohammed A. Omar, Sakakibara Masahito, Suzuki Toshikazu, Tanigawa Yasuo

Mechanical Engineering Faculty Patents

A system for detecting defects in paint coatings includes a temperature manipulation apparatus configured to change the temperature of a surface and a coating applied to the surface. The system may further include an infrared sensor for measuring the change in temperature of the surface and coating and a processor to compare the measured change in temperature of the surface and coating to an expected change of temperature in order to determine anomalies in the coatings.

Seal Assembly For Machinery Housing, Lyndon Scott Stephens, Kevin W. Kelly

Mechanical Engineering Faculty Patents

A seal assembly for a machinery housing includes a seal ring having a micro heat exchanger and a gland plate for securing the seal ring to the machinery housing. The gland plate includes a cooling fluid port in communication with the micro heat exchanger.

Heat Transfer And Chemical Processes In Chemical Vapor Deposition Reactor For Synthesis Of Carbon Nanotubes, Wahed Rezk Wasel

University of Kentucky Doctoral Dissertations

A small-scale model of a CVD reactor was built. Axial and radial of major species concentrations and temperature profiles were obtained with a micro gas chromatograph and a fine thermocouple. Those temperature and species concentrations revealed detailed thermal and chemical structures of the CVD reactor.

The concentrations of argon plus hydrogen, methane, and C₂H_x (C₂H₂ + C₂H₄ + C₂H₆) resulting from xylene decomposition were measured along the CVD at different temperatures. Ferrocene was added to xylene to investigate the effect of a catalyst on composition profiles. The …

New Ultra-Lightweight Stiff Panels For Space Apertures, Jonathan T. Black

University of Kentucky Doctoral Dissertations

Stiff, ultra-lightweight thermal-formed polyimide panels considered in this dissertation are examples of next generation gossamer structures that resolve some of the technology barriers of previous, membrane-dominated gossamer designs while maintaining their low mass and low stowage volume characteristics. The research involved statically and dynamically characterizing and modeling several of these panels to develop validated computer models which can be used to determine the effects of changing manufacturing parameters and scalability. Static characterization showed substantial local nonlinear behavior that was replicated by new physics-based finite element models, and global linear bending behavior that was modeled using classical shell finite elements incorporating …

Active Flow Control Of Low Pressure Turbine Blade Separation Using Plasma Actuators, Karthik Ramakumar

University of Kentucky Master's Theses

The current study examines plasma actuators as flow control devices. The actuators are placed on a turbine blade profile in a 2D turbine cascade for separation flow control. The configuration involves copper strips separated by a layer of dielectric material, across which an AC electric potential in the range of 5 kHz and 5 kV is applied. The efficiency of the actuator is monitored by measuring power input and flow control effectiveness. Preliminary observations are performed for a quiescent case on a flat plate profile to analyze the average and instantaneous velocities generated by the actuator for varied input parameters, …

Synthesis Of Multi-Wall Carbon Nanotubes Using Unseeded Hydrocarbon Diffusion Flames, Kozo Saito, Forman A. Williams, Alvin S. Gordon, Liming Yuang

Mechanical Engineering Faculty Patents

A method is provided for synthesizing carbon nanotubes from unseeded methane-air diffusion flames. A novel stainless steel and Ni—Cr wire probe is also provided for collecting carbon nanotubes from those diffusion flames.

Programmable Multi-Dose Intransal Drug Delivery Device, Daniel Wermeling, Ryan Vallance, Aravind Balasubramanian, Bruce L. Walcott, John Alan Main, James E. Lumpp Jr.

Mechanical Engineering Faculty Patents

An apparatus and method for the self-administration of a plurality of doses of an intranasal liquid pharmaceutical composition, including opioid analgesics, that includes a drug delivery device containing a plurality of sealed vials, each vial containing a predetermined volume of the pharmaceutical composition, a pump assembly for conveying the liquid pharmaceutical composition from the interior of the vial and discharging it as a nasal spray in response to manual activation by the patient, and programmable means for sequentially advancing a vial to the ready position after passage of a prescribed time interval following the last activation of the delivery device.

System And Device For Characterizing Shape Memory Alloy Wires, Robert Ryan Vallance, Bruce L. Walcott, James E. Lumpp, Sumanth Chikkamaranahalli, Osamah A. Rawashdeh, Eric Wolsing

Mechanical Engineering Faculty Patents

Instruments and methods for measuring a property of a shape memory alloy are provided. The instrument includes a base plate, a non-contact movable mass, a force gauge, an actuator, a biasing spring, a heater for heating the shape memory alloy, and a non-contact displacement detector. The biasing spring and the shape memory alloy are disposed whereby a force applied thereby is applied substantially through a center of stiffness of the movable mass. The displacement detector measures a displacement of the movable mass in a colinear direction with a direction of movement of the movable mass and with a direction of …

Evaluation Of A Mechanical System For Reconstructing Soil On Surface Mined Land, John P. Fulton, Larry G. Wells

Biosystems and Agricultural Engineering Faculty Publications

The existence of excessive soil compaction has hindered the surface mining industry from returning land to pre−mining productivity after reclamation, especially on prime farmland soils. Heavy earthmoving equipment used during reclamation tends to generate root−limiting bulk densities that adversely affect plant growth thereby decreasing yields. Therefore, the purpose of this study was to evaluate a mechanism, called the ‘Soil Regenerator,’ which reconstructs soil media at minimum bulk density during surface mine reclamation. The prototype soil forming mechanism was mounted on the front of a conventional bulldozer. Soil was placed in long narrow windrows by a scraper or bulldozer. As the …

Experimental Study Of Active Separation Flow Control In A Low Pressure Turbine Blade Cascade Model, Mark Mcquilling

University of Kentucky Master's Theses

The flow field around a low pressure turbine (LPT) blade cascade model with and without flow control is examined using ejector nozzle (EN) and vortex generator jet (VGJ) geometries for separation control. The cascade model consists of 6 Pak-B Pratt andamp; Whitney low pressure turbine blades with Re = 30,000-50,000 at a free-stream turbulence intensity of 0.6%. The EN geometry consists of combined suction and blowing slots near the point of separation. The VGJs consist of a row of holes placed at an angle to the free-stream, and are tested at two locations of 69% and 10.5% of the suction …

Processes For Nanomachining Using Carbon Nanotubes, Robert Ryan Vallance, Apparao M. Rao, M. Pinar Mengüç

Mechanical Engineering Faculty Patents

Novel methods and devices for nanomachining a desired pattern on a surface of a conductive workpiece are disclosed. In one aspect, the method comprises using an electron beam emitted from one or more nanotubes to evaporate nanoscale quantities of material from the workpiece surface. The surface of the workpiece to be machined may be excited to a threshold energy to reduce the amount of power required to be emitted by the nanotube. In another aspect, a device is described for nanomachining a desired pattern on a surface of a conductive workpiece, comprising a vessel capable of sustaining a vacuum, a …

Entrainment Of Electrical Activation By Spatio-Temporal Distributed Pacing During Ventricular Fibrillation, Yiping Gu

University of Kentucky Master's Theses

Spatio-temporal variation in action intervals during ventricular fibrillation (VF) suggestthat the excitable gap may also be distributed spatio-temporally. The observation leadus to hypothesize that distributed pacing can be used to modify and entrain electricalactivation during VF. We tested this hypothesis using simulated VF and animal studies.

We simulated VF in a 400 by 400 cell matrix. Simulation results showed that activationpattern could be entrained using spatially distributed stimulation. Up to a certain limit,increasing stimulus strength and density led to improved entrainment. Best entrainmentwas obtained by pacing at a cycle length similar to the intrinsic cycle length.

In order to verify …

Evaluation Of Fire-Fighting Helmet Surface Technology For High Radiant Heat Applications, David L. Barnett

University of Kentucky Master's Theses

Protective helmets used by fire-fighters must be designed to minimize the amount of heat transferred to the users head while providing durability, comfort, and affordable costs. This thesis highlights the evaluation of new helmet technology specifically tailored to high radiant heat environments to advance the state-of-the-art in head protection for this application. The research focused on the assessment of the outer shells of helmets and the properties of the surfaces. The development included the evaluation of radiation heat transfer, in a laboratory environment, to various helmet shell surface constructions. Industry standards were considered, and critiqued. Experiments were designed to isolate …

Experimental Investigation Of Separation In A Low Pressure Turbine Blade Cascade Model, Brian Hollon

University of Kentucky Master's Theses

The flow field around a low pressure turbine blade is examined using smoke-wire flow visualization, static surface pressure measurements, and particle image velocimetry (PIV). The purpose of the experimental study is to investigate the transition and separation characteristics on low pressure turbine blades under low Reynolds number (Re) and varying freestream turbulence intensity (FSTI). A cascade model consisting of 6 Pratt andamp; Whitney PAK-B low pressure turbine blades was examined in a wind tunnel using PIV and flow visualization. Smoke-wire visualization was performed for test section exit angles of 93°, 95°, and 97°, in the range Re = …

Measurements In A Rotating Serpentine Duct With Multiple Rib Arrangements, Rahul Bharadwajh

University of Kentucky Master's Theses

The effect of rotation on flow in a gas turbine blade cooling duct model is investigated experimentally. The present work consists of velocity measurements at different locations in a test section with a 180° bend with ribs on one wall. Three geometric rib parameters are considered; rib-rib spacing, rib orientation angle and rib blockage ratio. PIV is used for flow visualization and analysis. Along with the clean duct measurements, ribs with blockage ratios, b/h, of 0.25 and 0.125 were considered. The b/h = 0.25 cases have been comprehensively analyzed while the b/h = 0.125 cases have been studied at …

Study Of The "Poor Man's Navier-Stokes" Equation Turbulence Model, Stewart Andrew Bible

University of Kentucky Master's Theses

The work presented here is part of an ongoing effort to develop a highly accurate and numerically efficient turbulence simulation technique. The paper consists of four main parts, viz., the general discussion of the procedure known as Additive Turbulent Decomposition, the derivation of the "synthetic velocity" subgrid-scale model of the high wavenumber turbulent fluctuations necessary for its implementation, the numerical investigation of this model and a priori tests of said models physical validity. Through these investigations we have demonstrated that this procedure, coupled with the use of the "Poor Mans Navier-Stokes" equation subgrid-scale model, has the potential to be …

A Mechanical System For Soil Reconstruction, John Patrick Fulton, Larry G. Wells, Timothy D. Smith

Biosystems and Agricultural Engineering Faculty Publications

One of the most perplexing problems associated with reclaiming surface–mined lands is excessive compaction of soil due to the heavy earthmoving equipment used during the reclamation process. Over the years, some innovative material handling schemes have been devised to limit vehicle traffic during reclamation on reconstructed soil. However, final grading operations can often create root–limiting bulk densities, which affect plant growth and yield. The purpose of this article is to describe a mechanism designed at the University of Kentucky whereby mine soil can be reconstructed without introducing compaction caused by surface traffic in order for the soil to sustain desirable …

A Reduced–Cost Mechanized System For Handling And Curing Mechanically–Harvested Burley Tobacco, Greg A. Camenisch, Larry G. Wells, Timothy D. Smith, George A. Duncan

Biosystems and Agricultural Engineering Faculty Publications

An experimental system was tested in which mechanically harvested burley tobacco plants placed onto steel slotted receivers were retrieved from a field, transported to a field curing structure, and placed onto the structure for air curing by a single worker. The system consisted of a tractor–towed, trailer mechanism that engaged and hoisted loads of approximately 360 burley plants of approximately 1 Mg mass. Ten slotted steel rails, 3.05 m long, holding 36 notched plants were placed onto parallel wooden beams suspended at a height of 2.13 m by wooden posts set in the ground. Burley tobacco was cured in this …

Smart Material Control System And Related Method, John A. Main, George C. Nelson

Mechanical Engineering Faculty Patents

A smart material control system and related method is disclosed for adaptively controlling the movement of an adaptive structure. The adaptive structure includes a smart material layer bonded to a conductive substrate in a bimorph configuration. A charge projector, such as an electron gun, is utilized to project charges onto the smart material layer of the adaptive structure. A voltage/charge source adaptively controls the potential of the conductive substrate. Depending on the placement of the projected charges and the adaptively controlled potential of the conductive substrate the displacement/curvature is precisely controlled. In an alternate embodiment, two smart material layers are …

Piv Measurements Of Channel Flow With Multiple Rib Arrangements, Harald Roclawski

University of Kentucky Master's Theses

A model of a gas turbine blade cooling channel equipped with turbulators and a backward facing step geometry was examined. Up to four turbulators oriented cross-stream and inclined 45° to the flow direction were mounted in the channel. The blockage ratio b/H of the turbulators and the height h/H of the backward facing step was 0:125 and 0:14 respectively. The number of turbulators as well as their size was varied. In a preliminary investigation, hot-wire and pressure measurements were taken for three different Reynolds numbers (5,000, 12,000, 18,000)in the center plane of the test section. Subsequently, particle image …

Radiation Modulator System, M. Pinar Mengüç, Bruce L. Walcott, Stephen R. Swabb, Michael A. Marra Iii

Mechanical Engineering Faculty Patents

A radiation modulator system and related method for actively controlling a flame in a combustion system are provided. The system includes a plurality of radiation modulators positioned adjacent the flame. A sensor arrangement is provided for sensing combustion characteristics of the flame and generating a sensor signal representative of the combustion characteristics. The sensor signal is received in a computer which then generates a control signal for transmission to a linkage arrangement which provides for the repositioning of the radiation modulators. Thus, the flame is actively controlled by continually repositioning the modulators in response to the sensor signal and the …

Apparatus And Method For Measuring 3-D Weld Pool Shape, Radovan Kovacevic, Yu M. Zhang

Mechanical Engineering Faculty Patents

A method and apparatus are provided allowing the determination of 3-D weld pool surface geometry in the presence of a welding arc during a welding operation. The method includes the steps of illuminating the weld pool surface with diffused, structured light and detecting specular reflection of that diffused, structured light from the weld pool surface. An acquired image results. By analyzing the acquired image it is possible to determine the geometry of the weld pool surface. The apparatus for performing the method includes a high intensity light source, a diffuser and a structured light forming grid. A camera is provided …

Apparatus And Method Of High-Pressure Waterjet Assisted Cooling/Lubrication In Machining, Radovan Kovacevic

Mechanical Engineering Faculty Patents

An apparatus for high-pressure waterjet assisted machining includes a drive motor, spindle and rotary cutting tool with cutting inserts. The apparatus further includes a high-pressure intensifier pump providing cutting fluid at a pressure greater than 50,000 psi. A cutting fluid conduit system in the rotary cutting tool includes a main flow channel, a distribution manifold, a plurality of radially extending feed channels and a plurality of cooperating nozzles for delivering fluid behind the cutting inserts. The cutting fluid then passes through one or more apertures in the inserts into an interface defined by the inserts of the cutting tool and …

Active Vibration Control Device, Keith E. Rouch, Sanjiv Tewani, Bruce L. Walcott, Ted R. Massa, Robert W. Stephenson, L. Scott Stephens

Mechanical Engineering Faculty Patents

An active vibration control device for controlling vibration in a cantilevered member and a method for the same are disclosed. The device is comprised of a cantilevered member having a longitudinal axis comprising a sensor mounted near the free end of the member to measure motion of the member in a transverse direction and to produce a corresponding signal. A force generating assembly is mounted to the member near the free end to oppose the measured motion with a force thereby minimizing subsequent motion along the transverse axis caused by vibration.

Method And Apparatus For Conversion Of Coal In Situ, Ottfried J. Hahn

Mechanical Engineering Faculty Patents

A method for the electro-thermal and electrochemical underground conversion of coal into oil and by-products comprises the steps of inserting an underground probe into a bore hole until the probe is in close proximity to a coal seam. A mixture of air, steam, an electrolyte and a suitable catalyst is supplied to the probe, and the mixture is then sprayed directly on the coal seam through a passage in a nozzle. The probe is also energized with electricity applied to the nozzle to produce an arc between the coal and the probe, simultaneous with the spraying of the mixture on …

Retention Of Gasification-Combustion Products By Corn, S. W. Sizemore, Otto J. Loewer, Joseph L. Taraba, I. J. Ross, G. M. White

Biosystems and Agricultural Engineering Faculty Publications

Shelled corn was dried in layers of 5.1 cm (2 in.) 10.2 cm (4 in.), and 15.2 cm (6 in.) using air heated with the exhaust from a corn-cob fueled gasification-combustion updraft furnace. The drying air entering and leaving the grain layers was sampled for particulate content to determine the percentage of total particulates trapped by the grain during drying. It was determined that an average of 25% of the total particulates in the drying air were retained by the grain. The large majority of those particulates retained were found in the bottom 5.1 cm (2 in.) of the grain …

Bevolute Gear System, Willis M. Carter

Mechanical Engineering Faculty Patents

The present invention relates to a bevolute gearing system which transmits torque between non-intersecting shafts at right angles to each other. The bevolute gear system includes a pinion gear which is flat and in one plane. The pinion gear is designed to include teeth which are shaped in the form of an involute spiral. The bevolute gear system includes a second gear which is also designed to include teeth which are shaped in the form of an involute spiral. The second gear is mounted on a non-intersecting axis at a right angle to the axis of the pinion gear. The …