Open Access. Powered by Scholars. Published by Universities.^{®}
 Institution
 Keyword

 Airframes  Fatigue  Testing<br />Twinengine airplanes  Fatigue  Testing<br />Strains and stresses  Testing<br />Aerodynamics  Mathematical models (1)
 Extracellular matrix  Thermal conductivity<br />Heat  Conduction  Measurement<br />Metals  Thermal conductivity (1)
 Pneumatic tools  Noise<br />Noise control  Testing (1)
 Air flow  Mathematical models<br />Electric machinery  Rotors (1)
 Aerial  Computer simulation<br />Solid propellant rockets  Computer simulation<br />Ballistics  Computer simulation</p> (1)

 Plates (Engineering)  Mathematical models<br />Thermal stresses<br />Materials  Mechanical properties  Mathematical models<br />Shear (Mechanics)<br />Strains and stresses<br />Flexure (1)
 Flywheels<br />Oscillations  Mathematical models<br />Wave equation (1)
 Friction welding<br />Industrial equipment  Design and construction (1)
 Extracellular matrix  Thermal conductivity<br />Metallic composites  Thermal conductivity<br />Heat  Conduction  Measurement<br />Surfaces (Technology) (1)
 Film boiling  Testing<br />Heat  Transmission  Testing<br />Film boiling  Mathematical models (1)
 Damping (Mechanics)<br />Vibration  Mathematical models<br />Heat  Transmission  Mathematical models (1)
 Automobiles  Motors  Mufflers  Design<br />Automobiles  Motors  Mufflers  Evaluation<br />Automobiles  Motors  Mufflers  Acoustic properties (1)
 Magnetohydrodynamics<br />Channels (Hydraulic engineering)<br />Laminar flow  Mathematical models (1)
 Propulsion systems  Mathematical models<br />Electrohydrodynamics (1)
 Heat  Transmission<br />Mass transfer<br />Laminar flow  Computer simulation<br />Tubes  Fluid dynamics  Mathematical models (1)
 Electronic control<br />Measuring instruments  Design<br />Servomechanisms (1)
 Plasticity  Computer programs<br />Materials  Fatigue  Computer simulation<br />Strains and stresses  Mathematical models (1)
 <p>Steel  Surfaces  Thermal conductivity<br />Accommodation coefficient<br />Heat  Transmission  Measurement<br />Emissivity</p> (1)
 Abandonment of automobiles  Missouri  Saint Louis<br />Abandonment of automobiles  Environmental aspects (1)
 <p>Recoilless rifles  Computer simulation<br />Projectiles (1)
 Heat  Transmission<br />Radiative transfer<br />Isothermal transformation diagrams (1)
 Shock (Mechanics)<br />Heat  Radiation and absorption<br />Ablation (Aerothermodynamics) (1)
 Laminar flow  Mathematical models<br />Magnetohydrodynamics<br />Channels (Hydraulic engineering) (1)
 Angular speed (1)
 Extracellular matrix  Thermal conductivity<br />Heat  Conduction  Measurement<br />Surfaces (Technology) (1)
 Nucleate boiling<br />Heat  Transmission<br />Heat flux (1)
 Control systemsDesign and construction (1)
 Aerosols  Analysis<br />Particle size determination  Mathematical models<br />Light  Scattering (1)
 <p>Internal combustion engines  Exhaust gas<br />Automobiles  Motors  Exhaust gas  Prevention<br />Thermodynamic cycles<br />Rankine cycle<br />Working fluids</p> (1)
 Machinery  Vibration<br />Machinery  Vibration  Computer simulation<br />Machinery  Testing  Mathematical models<br />Structural dynamics  Mathematical models (1)
Articles 1  30 of 35
FullText Articles in Mechanical Engineering
Transient Response Of Linear Elastic Structures Determined By The Matrix Exponential Method, William Christopher Terrill Stoddart
Transient Response Of Linear Elastic Structures Determined By The Matrix Exponential Method, William Christopher Terrill Stoddart
Masters Theses
This investigation was undertaken to develop a numerical solution for the transient response of linear, elastic structures based on the matrix exponential solution for first order, linear, constant coefficient differential equations. The investigation was prompted by the need for an economical technique that can be used to analyze multidegree of freedom systems exemplified by piping and structural components associated with nuclear power plants.
A mathematical model characterizing the behavior of linear, elastic structures was developed by using state variables of displacement and velocity. The structure consists of beam elements of uniformly distributed mass, weightless springs, and rigid masses. The stiffness ...
A Study Of The Design And Construction Of A Full Scale Aircraft Component Demonstration Fatigue Test, Stephen Andrew Wright
A Study Of The Design And Construction Of A Full Scale Aircraft Component Demonstration Fatigue Test, Stephen Andrew Wright
Masters Theses
"The objective of this project was to design and build a full scale demonstration fatigue test for a Piper Aztec stabilator. A general discussion of the construction is included in this report. The Fourier series method of the aerodynamic theory of spanwise loading was used to determine the load distribution. The results show a close relationship with data furnished by Piper Aircraft Corporation. Fatigue theory is discussed in order to provide background for fatigue testing. The test specimen, methods and procedures of testing, known loading methods and systems, safety, etc., are discussed. Federal requirements for regulating and testing of aircraft ...
The Influence Of A Carbon Ablation Layer On Radiation From A Hydrogen Shock Layer, Birbal Singh
The Influence Of A Carbon Ablation Layer On Radiation From A Hydrogen Shock Layer, Birbal Singh
Masters Theses
"The effect of ablation heat shields on the radiative heat transfer to vehicles entering hydrogen atmospheres at thermodynamic conditions similar to those expected in Jovian atmospheres is investigated. The shock layer is assumed to consist of two plane parallel layers, one consisting of pure hydrogen species, and the other consisting of carbon species only. Each layer is assumed to be in local thermodynamic equilibrium at its respective temperature. The thermodynamic conditions in the hydrogen layer are arrived at by solving the RankineHugoniot Equations across the shock. The temperature of carbon layer is taken as (3000, 5000, and 7000ºK) to cover ...
An Investigation Of The Adjustable Element Concept For Design Of Automotive Exhaust Mufflers, Phillip Scott Gegesky
An Investigation Of The Adjustable Element Concept For Design Of Automotive Exhaust Mufflers, Phillip Scott Gegesky
Masters Theses
"The concept of the adjustable muffler is felt to be a step in the direction of easing the present tedium of constructing and testing prototype mufflers. The evaluation of such a muffler also furthers the knowledge of the interaction of acoustic elements. A review of past and present efforts in the design and evaluation of acoustic filters and filter elements is herein presented. Some consideration is given to phenomena, such as tube attenuation and transverse modes of vibration, which are encountered in muffler evaluation techniques. The characteristics of wave guides are discussed at length. The solution of the plane wave ...
A Digital Computer Program For Studying ElastoPlastic Structural Behavior Due To Cyclic Loading, Rameshchandra Chandulal Hazariwala
A Digital Computer Program For Studying ElastoPlastic Structural Behavior Due To Cyclic Loading, Rameshchandra Chandulal Hazariwala
Masters Theses
"A computer program has been developed to study the behavior of plane stress structures under cyclic loading. Such phenomena as thermal ratcheting, alternate plasticity, shakedown and the Bauschinger effect may be considered. The incremental theory of plasticity has been used. The program deals with realistic conditions such as nonlinear strain hardening, nonlinear temperature distribution and occurrence of both compressive and tensile plastic flow. The concept of an average material property has been used. Thermal ratcheting of a beam subjected to a constant bending moment and a temperature cycle has been studied in detail. The analysis shows analytically that the rate ...
Magnetohydrodynamic Stability Of Laminar Flow In The Entrance Region Of A ParallelPlate Channel, Thomas Eldon Eaton
Magnetohydrodynamic Stability Of Laminar Flow In The Entrance Region Of A ParallelPlate Channel, Thomas Eldon Eaton
Masters Theses
"The hydrodynamic stability of laminar flow of an electrically conducting fluid flowing in a parallelplate channel with an applied transverse magnetic field is investigated. The linear perturbation theory of hydrodynamic stability along with the assumption of low magnetic Reynolds number is applied to the governing equations to derive the governing rnagnetohydrodynarnic stability equation. A finite difference scheme is employed to numerically solve the magnetohydrodynamic stability equation. Neutral stability characteristics of the flow in the entrance region are obtained and presented. The neutral stability characteristics of the fully developed Hartmann flow are also reexamined and compared with those of a previous ...
Evaluation Of Cascaded Inertial Vibration Isolation Systems, Rajnikant Bhikhabhai Patel
Evaluation Of Cascaded Inertial Vibration Isolation Systems, Rajnikant Bhikhabhai Patel
Masters Theses
"Cascaded inertial vibration isolation systems are examined in this report. Systems employing one, two or three masses in series on isolators are investigated. The objective is to determine if the cascaded systems have appreciable advantages over the classical single mass system. The equations of motion for these systems are derived by applying Newton's second law of motion. The homogeneous and steady state sinusoidal excitation solutions have been established. Transmissibility of forces and moments to the foundation has been obtained for several cases of force excitation. Comparisons of the cases investigated are based upon the principal mode frequencies, mode shapes ...
Abandoned Automobiles :A Case History Of Land Pollution, Robert William Arden
Abandoned Automobiles :A Case History Of Land Pollution, Robert William Arden
Masters Theses
"A study has been made of the abandoned automobile problem as it now exists throughout the United States with particular emphasis on the problem in the Saint Louis area. The primary goal of this study was to determine those factors which most influence the collection and disposal of derelict vehicles. The problem was examined in the following major areas: (1) The history of the problem in the Saint Louis area and the various attempts made to correct it, (2) the various businesses directly involved with the disposal of junk automobiles, namely, the auto wreckers and the scrap processors, and (3 ...
Influence Of Some Interstitial Materials On The Thermal Contact Conductance, JinTyan Lin
Influence Of Some Interstitial Materials On The Thermal Contact Conductance, JinTyan Lin
Masters Theses
"Experiments have been conducted to investigate the effect of the interstitial materials at the interface of metals in contact. The test specimens were cylinders, axially aligned and loaded. Specimen materials were 606lT6 aluminum alloy, and the contact fillers were stainless steel wire screens, aluminum foil, paper, and dielectric greases. The tests were conducted at atmospheric environment. The contact pressure ranged from 25 psi to 600 psi. The mean interface temperature ranged from 100 ºF to 200 ºF. Surface roughnesses of specimens were from 25 to 35 microinches, rms. The results of the investigation reveal that if the contact surfaces are ...
Effect Of Inclination On Film Boiling, ShihChang Lin
Effect Of Inclination On Film Boiling, ShihChang Lin
Masters Theses
"The object of this investigation was to determine the effect of inclination on the heat transfer for film pool boiling. The test plate used as the heater was made of Inconel600 and heated electrically. Liquid nitrogen at atmospheric pressure was used as the test fluid. The heater was oriented at various angles from the horizontal position with the heater surface facing both upward and downward and the heat transfer coefficient was determined for each angle over temperature differences ranging from 450ºF to 750ºF. As the heater angle was increased from 0º (horizontal) to 90º (vertical), the heat transfer coefficient increased ...
Design And Construction Of A Velocity Control System For A Low Turbulence, Vertical Wind Tunnel, Lawrence Vehslage Field
Design And Construction Of A Velocity Control System For A Low Turbulence, Vertical Wind Tunnel, Lawrence Vehslage Field
Masters Theses
"A low velocity (0  11m/sec), low turbulence vertical atmospheric wind tunnel has been designed and built by Inca Engineering Company of San Gabriel, California. This tunnel was assembled in the Cloud Physics Research Center at UMR. The tunnel is designed to aid in the study of phenomena associated with water drops suspended in a vertical air stream. This thesis describes the design and construction of the velocity control system for this tunnel. Constant speed, centrifugal fans are used to draw air through the tunnel. To allow these fans to operate at a constant efficiency, a valve system is used ...
Linear Analysis Of Pneumatic Dashpot Damping, Nathalal Gordhanbhai Patel
Linear Analysis Of Pneumatic Dashpot Damping, Nathalal Gordhanbhai Patel
Masters Theses
"The linear analysis of pneumatic damping with orifice or capillary restrictions and with or without mean flow is presented. Temperature and pressure relationships are derived from energy considerations rather than the usual simplification of an assumed polytropic coefficient. Analytical results are compared with the experimental results and a coefficient of heat transfer, C_{h}, is defined for calculation of the equivalent linear damping factor C_{d}"Abstract, page ii.
Thermal Stresses In Circular Plates Including The Effect Of Transverse Shear Deformation, AnTon Liu
Thermal Stresses In Circular Plates Including The Effect Of Transverse Shear Deformation, AnTon Liu
Masters Theses
"This thesis is an extension of the work of T. F. Lehnhoff which used the method suggested by Goodier to develop the ReissnerGoodier small displacement theory for plates subjected to lateral loading. The purpose of this work is to develop a more complete ReissnerGoodier small displacement theory for plates under general loadings, both lateral and thermal, and to provide a solution to the six governing coupled partial differential equations by using a process similar to that of Lehnhoff. Any loading, lateral and/or thermal, that satisfies the Dirichlet conditions of Fourier analysis and virtually any boundary conditions may be handled ...
Influence Of Film Thickness On The Performance Of Solid Lubricants, Sunil Vishwanath Mahale
Influence Of Film Thickness On The Performance Of Solid Lubricants, Sunil Vishwanath Mahale
Masters Theses
"The object of this investigation was to determine the effect of lubricant film thickness on the coefficient of friction and on the wear life of solid lubricants. Bonded molybdenum disulphide and bonded graphite were the lubricants tested. Dow Corning's LFW1 and Falex lubricant tester were the two machines used for testing these lubricants. The lubricants were sprayed on the specimen surface. Pretreatment, spraying and curlng were done according to standard or manufacturer's recommended procedures. During the entire research, the procedure for experimentation was followed according to ASTM No. 2625 on Falex and CRC recommendations on LFW1 machine. It ...
Interface Thermal Conductance With Metal Screens As Interstitial Material, William Edward Stewart Jr.
Interface Thermal Conductance With Metal Screens As Interstitial Material, William Edward Stewart Jr.
Masters Theses
"This thesis reports the results of an experimental investigation to determine the thermal conductance at the interface of metal specimens separated by wire mesh. Sets of metal specimens of copper, 2024T4 aluminum, and 304 stainless steel were used. The specimens were cylindrical, axially aligned, and hydraulically loaded. All tests were conducted in an air environment. Pressure applied to the specimens ranged from 50 to 500 psig. Surface roughness of the interfaces varied from 5 to 20 micro inches. The wire mesh separators were of 304 stainless steel in 20, 30, 40, and 50 mesh. Results of the experiments show that ...
Transient Response Of A Vibration Isolation System, Hemendra Shantilal Acharya
Transient Response Of A Vibration Isolation System, Hemendra Shantilal Acharya
Masters Theses
"A practical procedure for investigating the performance of a vibration isolation system under transient conditions is presented. For this investigation, an induction motor with an unbalanced rotor is studied during the period when it accelerates to its operating speed from rest. Using Newton's second law of motion, equations of motion are derived, first neglecting and then considering the effect of "inertia torque". This torque is produced by the inertia force resulting from vertical acceleration of the unbalanced mass. The equations are solved on a digital computer using the RungeKutta method of order 4. The results obtained are compared with ...
Dynamic Analysis Of A Torsional Vibration Actuator, Narayandas Trikamdas Ashar
Dynamic Analysis Of A Torsional Vibration Actuator, Narayandas Trikamdas Ashar
Masters Theses
"The objective of this study is the evaluation of a mechanical system, which includes a Hooke's joint, as a possible torsional vibration actuator. The essential requirement of such a system is to produce a periodically varying angular motion superimposed upon a mean constant speed rotation. The basic kinematics of a Hooke's joint suggest that it could be used to generate the type of motion desired. The mechanical arrangement of a system incorporating a Hooke's joint is described and the governing differential equations are developed. These equations are simultaneous, differential equations of second order and are highly nonlinear ...
Vibration Of A Rotating Cantilever Beam With An Independently Rotating Disk On The Free End, Darrell Blaine Crimmins
Vibration Of A Rotating Cantilever Beam With An Independently Rotating Disk On The Free End, Darrell Blaine Crimmins
Masters Theses
"This thesis provides a vibration analysis of a rotating cantilever beam with an independently rotating thin circular disk on the free end. The exact differential equations of the system as defined by classical BernoulliEuler beam theory are written using the methods of the calculus of variations. The exact equations are not solved, but two different approximations are found by assuming a cubic polynomial deflection curve and applying the equation of Lagrange. The solutions are restricted to small deflections of the beam and a shaft stiffness which permits a deflection in only a single plane. Nonlinear differential equations result in the ...
A Transient Method Of Negligible Internal Thermal Resistance For Determining Thermal Contact Conductance In A Vacuum, Richard Chuka Oboka
A Transient Method Of Negligible Internal Thermal Resistance For Determining Thermal Contact Conductance In A Vacuum, Richard Chuka Oboka
Masters Theses
"A transient method for experimentally determining the interface conductance between metallic surfaces in contact is developed. The method applies the theory of negligible internal thermal resistance of one of the materials which form the interface. The method is applicable when the interface conductance is very low, a situation which exists when low conductance interstitial materials are used between contacting surfaces for purposes of thermal isolation. In this investigation, stainless steel wire screens of 10 and 100 mesh were used as interstitial materials between aluminum surfaces in a vacuum environment of 10⁻⁵ to 10⁻⁶ Torr. The interface pressure ranged ...
Effect Of Surface Conditions On Nucleate Pool Boiling Of Refrigerant11, Abbas M. Sinnarwalla
Effect Of Surface Conditions On Nucleate Pool Boiling Of Refrigerant11, Abbas M. Sinnarwalla
Masters Theses
"The purpose of this investigation was to determine the effect of surface conditions on the heat transfer for nucleate pool boiling from flat horizontal surfaces. Experiments were carried out using Refrigerant11 at atmospheric pressure as the test fluid with Inconel600 as the heater material. The heat transfer coefficient was determined for mirror finished, chemically etched, glass beaded and sandpaper roughened heater surfaces over heat flux ranging for 0 to 18000 BTU/HR SQ FT. At a given heat flux, the heat transfer coefficient was found to be the lowest for mirror finished surface and the highest for sandpaper roughened surface ...
Magnetohydrodynamic Channel Flow With NonUniform Inlet Velocity Profiles, GwokLiang Chen
Magnetohydrodynamic Channel Flow With NonUniform Inlet Velocity Profiles, GwokLiang Chen
Masters Theses
"An analysis is made of laminar magnetohydrodynamic (MHD) flow development in the entrance region of a parallelplate channel. The problem is formulated in general for any velocity distribution at the channel inlet by extending the linearization method of Sparrow, Lin, and Lundgren for nonMHD duct flows. This method involves linearization of the inertia terms in the equation of motion by introducing a stretched axial coordinate. A closed form solution is obtained for the velocity distributions which are continuous across the channel and along the length all the way from the entrance to the fully developed region. An expression for the ...
The Closed CycleExternal Combustion Engine And Air Pollution, Galen Lee Pearson
The Closed CycleExternal Combustion Engine And Air Pollution, Galen Lee Pearson
Masters Theses
"The impact of the internal combustion engine on the air pollution problem in this country was presented and alternative propulsion systems for the land transportation vehicle were investigated. The potential characteristics of the more promising closed cycleexternal combustion engine concepts were established and discussed. The closed thermodynamic power cycles analyzed include the Rankine, Stirling, and Feher supercritical cycles. Thermodynamic property data on eighteen candidate working fluids for the Rankine and Feher supercritical power cycles have been assembled and were presented in a utilizable form. The thermal efficiency (ratio of the net work out to the heat input) and the many ...
Measurement Of Thermal Accommodation Coefficients Of Steel Surfaces, Wing On Ho
Measurement Of Thermal Accommodation Coefficients Of Steel Surfaces, Wing On Ho
Masters Theses
"The thermal accommodation coefficient plays an important role in low density thermal energy transfer measurement. The object of this investigation was to measure the thermal energy transfer between a heated test surface and a water cooled reference surface (flat black lacquer) consisting of two infinite concentric cylinders separated by dry air. Two machined and sanded steel cylinders with mean surface roughnesses of 25 microinches and 7.5 microinches were used as the test surfaces . Measurements were made in the pressure range of 1.2 x 10⁻⁶ mm Hg. to 1.8 x 10⁻⁶ mm Hg. and temperature range ...
A Computer Simulation Of The Internal Ballistics Of RecoillessRifle Rocket Launchers, John Edd Mosier
A Computer Simulation Of The Internal Ballistics Of RecoillessRifle Rocket Launchers, John Edd Mosier
Masters Theses
"A computer program has been developed to simulate the basic mechanics and gas dynamics associated with launching a solid propellant rocket from a recoilless rifle. This program, entitled "KICKIT," may be used to predict the performance and evaluate many of the pertinent design parameters of both conventional recoilless rifles and a recoilless rocket launcher system. This program is a valuable analytical tool which enables the designer either to optimize the system design or predict the behavior of the system under offdesign conditions"Abstract, Page ii.
On The Flow Near An Enclosed Rotating Blade In The Neighborhood Of The Ground, TzeLien Liang
On The Flow Near An Enclosed Rotating Blade In The Neighborhood Of The Ground, TzeLien Liang
Masters Theses
"The flow in the vicinity of an enclosed rotating blade near the ground was studied both analytically and experimentally. Experimental results were obtained by making pitot tube traverses across the face of the housing but gave only a qualitative indication of the velocity distribution. Tufts of strings were used to locate the flow directions in the vicinity of the ground and the housing. The two dimensional potential flow solution was found to yield unreasonable results for this flow configuration due to viscous and rotative effects. The threedimensional NavierStokes equations were solved numerically by using the successive underrelaxation method. The results ...
Analysis And Control Of Noise Produced By Small Pneumatic Tools, Phillip Ray Elam
Analysis And Control Of Noise Produced By Small Pneumatic Tools, Phillip Ray Elam
Masters Theses
"Noise measurements were made near the exhaust of three small pneumatic tools operating under various loads and with various components removed. Onethird octave analyses were performed on the noise for identification of noise sources and to determine possible noise reduction techniques. It was determined that the noise spectra consisted of broad band turbulent flow noise plus periodic components at the tool motor blade passage frequency and harmonics of this frequency. One tool, the nut setter, was selected for reverberant field noise analyses and noise reduction studies. Reverberant field measurements indicated that most of the tool noise was transmitted through the ...
The Development And Analysis Of A System To Measure Transient Angular Velocity, David Lawrence Persson
The Development And Analysis Of A System To Measure Transient Angular Velocity, David Lawrence Persson
Masters Theses
"A measuring system was built to provide a D. C. voltage which was proportional to the angular speed of a particular rotating shaft under question. The measuring system developed has a time constant of approximately .00365 seconds. The final measuring system was developed after trying various other means which proved unsatisfactory. The final device developed would be quite satisfactory in a wide variety of applications"Abstract, page ii.
Analysis Of Elastic Thermal Stresses By StationFunction Collocation Methods, JawKuang Wang
Analysis Of Elastic Thermal Stresses By StationFunction Collocation Methods, JawKuang Wang
Masters Theses
"An approximate method for the solution of thermal stress problems is presented. The method makes use of polynomial approximations to reduce the partial differential equation to a system of linear algebraic equations or a set of firstorder ordinary differential equations. This results in satisfying the differential equation at a finite number of stations. The boundary conditions are satisfied identically. Two examples of the method, presented in detail, indicate that the solutions of the biharmonic equation for the stress function and the Fourier equation for the temperature distribution have good accuracy with a minimum of labor. A generalized method is derived ...
The Design And Construction Of An Inertia Welder, Arthur Ferdinand Grimm
The Design And Construction Of An Inertia Welder, Arthur Ferdinand Grimm
Masters Theses
"The purpose of this investigation was the design and fabrication of a machine to bond metal to metal using the inertia method of friction welding. This method of bonding is considered far superior to the heretofore employed friction welding processes as will be explained later. The inertia method controls the energy imparted to the weld by using a flywheel which has been brought to a state of predetermined kinetic energy due to rotation. This energy is then transferred to the weld zone in the form of heat due to rotational friction. Hollow specimens with a crosssectional area of 0.306 ...
Efficiency And Loss Mechanism Of The ElectroFluid Dynamic Momentum Transfer Process Applied To Propulsion Systems Using Atmospheric Air As The Working Fluid, Roger Coy Crites
Efficiency And Loss Mechanism Of The ElectroFluid Dynamic Momentum Transfer Process Applied To Propulsion Systems Using Atmospheric Air As The Working Fluid, Roger Coy Crites
Masters Theses
"The general equations governing EFD (electrofluid dynamic) flow are established, simplified, and solved in closed form to provide a mathematical model of an ideal EFD propulsion system. This mathematical model, in conjunction with an analysis of ionneutral and neutralneutral molecular collision phenomena, indicates that the cause of inefficiency in the EFD propulsion system is the system entropy increase associated with the diffusion of ion momentum through the neutral fluid. This loss mechanism is shown to be analogous to resistive heating losses in a constant voltage linear electrical network and can be minimized by obtaining minimum ion mobility. It is shown ...