Uniform Plane Waves
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Design and Analysis of a Single Stage, Traveling Wave, Thermoacoustic Engine for Bi-Directional Turbine Generator Integration Mitchell Mcgaughy Clemson University
Clemson University TigerPrints All Theses Theses 12-2018 Design and Analysis of a Single Stage, Traveling Wave, Thermoacoustic Engine for Bi-Directional Turbine Generator Integration Mitchell McGaughy Clemson University Follow this and additional works at: https://tigerprints.clemson.edu/all_theses Part of the Mechanical Engineering Commons Recommended Citation McGaughy, Mitchell, "Design and Analysis of a Single Stage, Traveling Wave, Thermoacoustic Engine for Bi-Directional Turbine Generator Integration" (2018). All Theses. 2962. https://tigerprints.clemson.edu/all_theses/2962 This Thesis is brought to you for free and open access by the Theses at TigerPrints. It has been accepted for inclusion in All Theses by an authorized administrator of TigerPrints. For more information, please contact [email protected]. DESIGN AND ANALYSIS OF A SINGLE STAGE, TRAVELING WAVE, THERMOACOUSTIC ENGINE FOR BI-DIRECTIONAL TURBINE GENERATOR INTEGRATION A Thesis Presented to the Graduate School of Clemson University In Partial Fulfillment of the Requirements for the Degree Master of Science Mechanical Engineering by Mitchell McGaughy December 2018 Accepted by: Dr. John R. Wagner, Committee Co-Chair Dr. Thomas Salem, Committee Co-Chair Dr. Todd Schweisinger, Committee Member ABSTRACT The demand for clean, sustainable, and cost-effective energy continues to increase due to global population growth and corresponding use of consumer products. Thermoacoustic technology potentially offers a sustainable and reliable solution to help address the continuing demand for electric power. A thermoacoustic device, operating on the principle of standing or traveling acoustic waves, can be designed as a heat pump or a prime mover system. The provision of heat to a thermoacoustic prime mover results in the generation of an acoustic wave that can be converted into electrical power. -
Ec6503 - Transmission Lines and Waveguides Transmission Lines and Waveguides Unit I - Transmission Line Theory 1
EC6503 - TRANSMISSION LINES AND WAVEGUIDES TRANSMISSION LINES AND WAVEGUIDES UNIT I - TRANSMISSION LINE THEORY 1. Define – Characteristic Impedance [M/J–2006, N/D–2006] Characteristic impedance is defined as the impedance of a transmission line measured at the sending end. It is given by 푍 푍0 = √ ⁄푌 where Z = R + jωL is the series impedance Y = G + jωC is the shunt admittance 2. State the line parameters of a transmission line. The line parameters of a transmission line are resistance, inductance, capacitance and conductance. Resistance (R) is defined as the loop resistance per unit length of the transmission line. Its unit is ohms/km. Inductance (L) is defined as the loop inductance per unit length of the transmission line. Its unit is Henries/km. Capacitance (C) is defined as the shunt capacitance per unit length between the two transmission lines. Its unit is Farad/km. Conductance (G) is defined as the shunt conductance per unit length between the two transmission lines. Its unit is mhos/km. 3. What are the secondary constants of a line? The secondary constants of a line are 푍 i. Characteristic impedance, 푍0 = √ ⁄푌 ii. Propagation constant, γ = α + jβ 4. Why the line parameters are called distributed elements? The line parameters R, L, C and G are distributed over the entire length of the transmission line. Hence they are called distributed parameters. They are also called primary constants. The infinite line, wavelength, velocity, propagation & Distortion line, the telephone cable 5. What is an infinite line? [M/J–2012, A/M–2004] An infinite line is a line where length is infinite. -
Acoustics: the Study of Sound Waves
Acoustics: the study of sound waves Sound is the phenomenon we experience when our ears are excited by vibrations in the gas that surrounds us. As an object vibrates, it sets the surrounding air in motion, sending alternating waves of compression and rarefaction radiating outward from the object. Sound information is transmitted by the amplitude and frequency of the vibrations, where amplitude is experienced as loudness and frequency as pitch. The familiar movement of an instrument string is a transverse wave, where the movement is perpendicular to the direction of travel (See Figure 1). Sound waves are longitudinal waves of compression and rarefaction in which the air molecules move back and forth parallel to the direction of wave travel centered on an average position, resulting in no net movement of the molecules. When these waves strike another object, they cause that object to vibrate by exerting a force on them. Examples of transverse waves: vibrating strings water surface waves electromagnetic waves seismic S waves Examples of longitudinal waves: waves in springs sound waves tsunami waves seismic P waves Figure 1: Transverse and longitudinal waves The forces that alternatively compress and stretch the spring are similar to the forces that propagate through the air as gas molecules bounce together. (Springs are even used to simulate reverberation, particularly in guitar amplifiers.) Air molecules are in constant motion as a result of the thermal energy we think of as heat. (Room temperature is hundreds of degrees above absolute zero, the temperature at which all motion stops.) At rest, there is an average distance between molecules although they are all actively bouncing off each other. -
Waveguides Waveguides, Like Transmission Lines, Are Structures Used to Guide Electromagnetic Waves from Point to Point. However
Waveguides Waveguides, like transmission lines, are structures used to guide electromagnetic waves from point to point. However, the fundamental characteristics of waveguide and transmission line waves (modes) are quite different. The differences in these modes result from the basic differences in geometry for a transmission line and a waveguide. Waveguides can be generally classified as either metal waveguides or dielectric waveguides. Metal waveguides normally take the form of an enclosed conducting metal pipe. The waves propagating inside the metal waveguide may be characterized by reflections from the conducting walls. The dielectric waveguide consists of dielectrics only and employs reflections from dielectric interfaces to propagate the electromagnetic wave along the waveguide. Metal Waveguides Dielectric Waveguides Comparison of Waveguide and Transmission Line Characteristics Transmission line Waveguide • Two or more conductors CMetal waveguides are typically separated by some insulating one enclosed conductor filled medium (two-wire, coaxial, with an insulating medium microstrip, etc.). (rectangular, circular) while a dielectric waveguide consists of multiple dielectrics. • Normal operating mode is the COperating modes are TE or TM TEM or quasi-TEM mode (can modes (cannot support a TEM support TE and TM modes but mode). these modes are typically undesirable). • No cutoff frequency for the TEM CMust operate the waveguide at a mode. Transmission lines can frequency above the respective transmit signals from DC up to TE or TM mode cutoff frequency high frequency. for that mode to propagate. • Significant signal attenuation at CLower signal attenuation at high high frequencies due to frequencies than transmission conductor and dielectric losses. lines. • Small cross-section transmission CMetal waveguides can transmit lines (like coaxial cables) can high power levels. -
Wave Equations, Wavepackets and Superposition Michael Fowler, Uva 9/14/06
Wave Equations, Wavepackets and Superposition Michael Fowler, UVa 9/14/06 A Challenge to Schrödinger De Broglie’s doctoral thesis, defended at the end of 1924, created a lot of excitement in European physics circles. Shortly after it was published in the fall of 1925 Pieter Debye, a theorist in Zurich, suggested to Erwin Schrödinger that he give a seminar on de Broglie’s work. Schrödinger gave a polished presentation, but at the end Debye remarked that he considered the whole theory rather childish: why should a wave confine itself to a circle in space? It wasn’t as if the circle was a waving circular string, real waves in space diffracted and diffused, in fact they obeyed threedimensional wave equations, and that was what was needed. This was a direct challenge to Schrödinger, who spent some weeks in the Swiss mountains working on the problem, and constructing his equation. There is no rigorous derivation of Schrödinger’s equation from previously established theory, but it can be made very plausible by thinking about the connection between light waves and photons, and construction an analogous structure for de Broglie’s waves and electrons (and, later, other particles). Maxwell’s Wave Equation Let us examine what Maxwell’s equations tell us about the motion of the simplest type of electromagnetic wave—a monochromatic wave in empty space, with no currents or charges present. As we discussed in the last lecture, Maxwell found the wave equation r r 1 ¶ 2 E Ñ2 E - = 0 . c2 ¶ t 2 which reduces to r r ¶ 2 E 1 ¶ 2 E - = 0 ¶ x2 c2 ¶ t 2 for a plane wave moving in the xdirection, with solution r r i ( kx - w t ) E ( x , t ) = E 0 e . -
Wave Guides Summary and Problems
ECE 144 Electromagnetic Fields and Waves Bob York General Waveguide Theory Basic Equations (ωt γz) Consider wave propagation along the z-axis, with fields varying in time and distance according to e − . The propagation constant γ gives us much information about the character of the waves. We will assume that the fields propagating in a waveguide along the z-axis have no other variation with z,thatis,the transverse fields do not change shape (other than in magnitude and phase) as the wave propagates. Maxwell’s curl equations in a source-free region (ρ =0andJ = 0) can be combined to give the wave equations, or in terms of phasors, the Helmholtz equations: 2E + k2E =0 2H + k2H =0 ∇ ∇ where k = ω√µ. In rectangular or cylindrical coordinates, the vector Laplacian can be broken into two parts ∂2E 2E = 2E + ∇ ∇t ∂z2 γz so that with the assumed e− dependence we get the wave equations 2E +(γ2 + k2)E =0 2H +(γ2 + k2)H =0 ∇t ∇t (ωt γz) Substituting the e − into Maxwell’s curl equations separately gives (for rectangular coordinates) E = ωµH H = ωE ∇ × − ∇ × ∂Ez ∂Hz + γEy = ωµHx + γHy = ωEx ∂y − ∂y ∂Ez ∂Hz γEx = ωµHy γHx = ωEy − − ∂x − − − ∂x ∂Ey ∂Ex ∂Hy ∂Hx = ωµHz = ωEz ∂x − ∂y − ∂x − ∂y These can be rearranged to express all of the transverse fieldcomponentsintermsofEz and Hz,giving 1 ∂Ez ∂Hz 1 ∂Ez ∂Hz Ex = γ + ωµ Hx = ω γ −γ2 + k2 ∂x ∂y γ2 + k2 ∂y − ∂x w W w W 1 ∂Ez ∂Hz 1 ∂Ez ∂Hz Ey = γ + ωµ Hy = ω + γ γ2 + k2 − ∂y ∂x −γ2 + k2 ∂x ∂y w W w W For propagating waves, γ = β,whereβ is a real number provided there is no loss. -
Lecture 13: Electromagnetic Waves
Matthew Schwartz Lecture 13: Electromagnetic waves 1 Light as waves In previous classes (15a, high school physics), you learned to think about light as rays. Remember tracing light as lines through a curved lens and seeing whether the image was inverted or right side up and so on? This ray-tracing business is known as geometrical optics. It applies in the limit that the wavelength of light is much smaller than the objects which are bending and moving the light around. We’re not going to cover geometrical optics much in 15c (except for what you do in lab). Approaching light as waves will allow us to understand topics of polarization, interference, and diffraction which you may not have seen in a physics class before. Electromagnetic waves can have any wavelength. Electromagnetic waves with wavelengths in 6 the visible spectrum (λ ∼ 10− m) are called light. Red light has a longer wavelength than blue light. Longer wavelengths than red go into infrared, then microwaves, then radio waves. Smaller wavelengths than blue are ultraviolet, then x rays than γ rays. Here is a diagram of the spec- trum: Figure 1. Electromagnetic spectrum λ ν c E hν It is helpful to go back and forth between wavelengths , frequency = λ and energy = , 34 where h = 6.6 × 10− J · s is Planck’s constant. The fact that energy and frequency are linearly related is a shocking consequence of quantum mechanics. In fact, although light is wavelike, it is made up of particles called photons. A photon of frequency ν has energy E = hν. -
Microstrip Solutions for Innovative Microwave Feed Systems
Examensarbete LiTH-ITN-ED-EX--2001/05--SE Microstrip Solutions for Innovative Microwave Feed Systems Magnus Petersson 2001-10-24 Department of Science and Technology Institutionen för teknik och naturvetenskap Linköping University Linköpings Universitet SE-601 74 Norrköping, Sweden 601 74 Norrköping LiTH-ITN-ED-EX--2001/05--SE Microstrip Solutions for Innovative Microwave Feed Systems Examensarbete utfört i Mikrovågsteknik / RF-elektronik vid Tekniska Högskolan i Linköping, Campus Norrköping Magnus Petersson Handledare: Ulf Nordh Per Törngren Examinator: Håkan Träff Norrköping den 24 oktober, 2001 'DWXP $YGHOQLQJ,QVWLWXWLRQ Date Division, Department Institutionen för teknik och naturvetenskap 2001-10-24 Ã Department of Science and Technology 6SUnN 5DSSRUWW\S ,6%1 Language Report category BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB Svenska/Swedish Licentiatavhandling X Engelska/English X Examensarbete ISRN LiTH-ITN-ED-EX--2001/05--SE C-uppsats 6HULHWLWHOÃRFKÃVHULHQXPPHUÃÃÃÃÃÃÃÃÃÃÃÃ,661 D-uppsats Title of series, numbering ___________________________________ _ ________________ Övrig rapport _ ________________ 85/I|UHOHNWURQLVNYHUVLRQ www.ep.liu.se/exjobb/itn/2001/ed/005/ 7LWHO Microstrip Solutions for Innovative Microwave Feed Systems Title )|UIDWWDUH Magnus Petersson Author 6DPPDQIDWWQLQJ Abstract This report is introduced with a presentation of fundamental electromagnetic theories, which have helped a lot in the achievement of methods for calculation and design of microstrip transmission lines and circulators. The used software for the work is also based on these theories. General considerations when designing microstrip solutions, such as different types of transmission lines and circulators, are then presented. Especially the design steps for microstrip lines, which have been used in this project, are described. Discontinuities, like bends of microstrip lines, are treated and simulated. -
The Acoustic Wave Equation and Simple Solutions
Chapter 5 THE ACOUSTIC WAVE EQUATION AND SIMPLE SOLUTIONS 5.1INTRODUCTION Acoustic waves constitute one kind of pressure fluctuation that can exist in a compressible fluido In addition to the audible pressure fields of modera te intensity, the most familiar, there are also ultrasonic and infrasonic waves whose frequencies lie beyond the limits of hearing, high-intensity waves (such as those near jet engines and missiles) that may produce a sensation of pain rather than sound, nonlinear waves of still higher intensities, and shock waves generated by explosions and supersonic aircraft. lnviscid fluids exhibit fewer constraints to deformations than do solids. The restoring forces responsible for propagating a wave are the pressure changes that oc cur when the fluid is compressed or expanded. Individual elements of the fluid move back and forth in the direction of the forces, producing adjacent regions of com pression and rarefaction similar to those produced by longitudinal waves in a bar. The following terminology and symbols will be used: r = equilibrium position of a fluid element r = xx + yy + zz (5.1.1) (x, y, and z are the unit vectors in the x, y, and z directions, respectively) g = particle displacement of a fluid element from its equilibrium position (5.1.2) ü = particle velocity of a fluid element (5.1.3) p = instantaneous density at (x, y, z) po = equilibrium density at (x, y, z) s = condensation at (x, y, z) 113 114 CHAPTER 5 THE ACOUSTIC WAVE EQUATION ANO SIMPLE SOLUTIONS s = (p - pO)/ pO (5.1.4) p - PO = POS = acoustic density at (x, y, Z) i1f = instantaneous pressure at (x, y, Z) i1fO = equilibrium pressure at (x, y, Z) P = acoustic pressure at (x, y, Z) (5.1.5) c = thermodynamic speed Of sound of the fluid <I> = velocity potential of the wave ü = V<I> . -
Electrodynamic Fields: the Superposition Integral Point of View
MIT OpenCourseWare http://ocw.mit.edu Haus, Hermann A., and James R. Melcher. Electromagnetic Fields and Energy. Englewood Cliffs, NJ: Prentice-Hall, 1989. ISBN: 9780132490207. Please use the following citation format: Haus, Hermann A., and James R. Melcher, Electromagnetic Fields and Energy. (Massachusetts Institute of Technology: MIT OpenCourseWare). http://ocw.mit.edu (accessed [Date]). License: Creative Commons Attribution-NonCommercial-Share Alike. Also available from Prentice-Hall: Englewood Cliffs, NJ, 1989. ISBN: 9780132490207. Note: Please use the actual date you accessed this material in your citation. For more information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms 12 ELECTRODYNAMIC FIELDS: THE SUPERPOSITION INTEGRAL POINT OF VIEW 12.0 INTRODUCTION This chapter and the remaining chapters are concerned with the combined effects of the magnetic induction ∂B/∂t in Faraday’s law and the electric displacement current ∂D/∂t in Amp`ere’s law. Thus, the full Maxwell’s equations without the quasistatic approximations form our point of departure. In the order introduced in Chaps. 1 and 2, but now including polarization and magnetization, these are, as generalized in Chaps. 6 and 9, � · (�oE) = ρu − � · P (1) ∂ � × H = J + (� E + P) (2) u ∂t o ∂ � × E = − µ (H + M) (3) ∂t o � · (µoH) = −� · (µoM) (4) One may question whether a generalization carried out within the formalism of electroquasistatics and magnetoquasistatics is adequate to be included in the full dynamic Maxwell’s equations, and some remarks are in order. Gauss’ law for the electric field was modified to include charge that accumulates in the polarization process. -
Handbook of Optics
P d A d R d T d 2 PHYSICAL OPTICS CHAPTER 2 INTERFERENCE John E. Greivenkamp Optical Sciences Center Uniy ersity of Arizona Tucson , Arizona 2. 1 GLOSSARY A amplitude E electric field vector r position vector x , y , z rectangular coordinates f phase 2. 2 INTRODUCTION Interference results from the superposition of two or more electromagnetic waves . From a classical optics perspective , interference is the mechanism by which light interacts with light . Other phenomena , such as refraction , scattering , and dif fraction , describe how light interacts with its physical environment . Historically , interference was instrumental in establishing the wave nature of light . The earliest observations were of colored fringe patterns in thin films . Using the wavelength of light as a scale , interference continues to be of great practical importance in areas such as spectroscopy and metrology . 2. 3 WAVES AND WAVEFRONTS The electric field y ector due to an electromagnetic field at a point in space is composed of an amplitude and a phase E ( x , y , z , t ) 5 A ( x , y , z , t ) e i f ( x ,y ,z ,t ) (1) or E ( r , t ) 5 A ( r , t ) e i f ( r , t ) (2) where r is the position vector and both the amplitude A and phase f are functions of the spatial coordinate and time . As described in Chap . 5 , ‘‘Polarization , ’’ the polarization state of the field is contained in the temporal variations in the amplitude vector . 2 .3 2 .4 PHYSICAL OPTICS This expression can be simplified if a linearly polarized monochromatic wave is assumed : E ( x , y , z , t ) 5 A ( x , y , z ) e i [ v t 2 f ( x ,y ,z )] (3) where v is the angular frequency in radians per second and is related to the frequency … by v 5 2 π … (4) Some typical values for the optical frequency are 5 3 10 1 4 Hz for the visible , 10 1 3 Hz for the infrared , and 10 1 6 Hz for the ultraviolet . -
Simple Derivation of Electromagnetic Waves from Maxwell's Equations
Simple Derivation of Electromagnetic Waves from Maxwell’s Equations By Lynda Williams, Santa Rosa Junior College Physics Department Assume that the electric and magnetic fields are constrained to the y and z directions, respectfully, and that they are both functions of only x and t. This will result in a linearly polarized plane wave travelling in the x direction at the speed of light c. Ext( , ) Extj ( , )ˆ and Bxt( , ) Bxtk ( , ) ˆ We will derive the wave equation from Maxwell’s Equations in free space where I and Q are both zero. EB 0 0 BE EB με tt00 iˆˆ j kˆ E Start with Faraday’s Law. Take the curl of the E field: E( x , t )ˆ j = kˆ x y z x 0E ( x , t ) 0 EB Equating magnitudes in Faraday’s Law: (1) xt This means that the spatial variation of the electric field gives rise to a time-varying magnetic field, and visa-versa. In a similar fashion we derive a second equation from Ampere-Maxwell’s Law: iˆˆ j kˆ BBE Take the curl of B: B( x , t ) kˆ = ˆ j (2) x y z x x00 t 0 0B ( x , t ) This means that the spatial variation of the magnetic field gives rise to a time-varying electric field, and visa-versa. Take the partial derivative of equation (1) with respect to x and combining the results from (2): 22EBBEE 22 = 0 0 0 0 x x t t x t t t 22EE (3) xt2200 22BB In a similar manner, we can derive a second equation for the magnetic field: (4) xt2200 Both equations (3) and (4) have the form of the general wave equation for a wave (,)xt traveling in 221 the x direction with speed v: .