Understanding electricity with hydraulics technical articles. There is a very close analogy between mechanical and electrical motion. Electro mechanical analogies direct analogy indirect analogy 14 simple mechanical system 16 analogy comparison 17 a. Next, power dissipation of the forced, simple springmass system will be discussed in order to. Rlc series circuits resonance behavior reference serway chapt. Using analogies to explain electrical relationships. Mechanical systems electrical systems electronic systems thermal systems hydraulic systems chemical systems first off we need to understand why do we need to model these systems in the first place. Harvard university division of engineering and applied. The electro mechanical analogy can be classified into two categories. Electromechanical analogies direct analogy indirect analogy 14 simple mechanical system 16 analogy comparison 17 a. Here you can compare the equation 4 and equation 6 and we will get the analogous quantities of rotational mechanical system and electrical system. This is translated, and its problem j of j problems, so i might have missed writing down something important along the way. Weaver, facility manager, birck nanotechnology center. The behavior of the analogous mechanical and electrical systems is defined by the same types of differential equations as is evident from a comparison of eq.
Having developed electriccircuit theory to a high degree,it becomes desirable to use same analogy to make possible a more convenient treatement of mechanical systems. Nigel calder is widely acknowledged as the worlds foremost writer on boat systems maintenance. Mechanical quantity symbol electrical quantity symbol mass m inductance l. Electro mechanical analogies we will now represent the phenomena existing in mechanical systems, by an equivalent electrical network. Electrical analogies of mechanical systems in control systems. The electrical to heat conduction analogy allows one to apply laws from circuit theory to solve more complicated conduction problems, such as the heat flow through conducting layers attached in parallel or series. Electrical analogies of mechanical systems in control systems electrical analogies of mechanical systems in control systems courses with reference manuals and examples pdf.
Electric potential is more commonly known as voltage and for uniform fields. Mechanical and electrical equipment for buildings quiz context for building system design chapter 1 the three phases of the design process are generally known as. This mechanical oscillator has energy e and angular. A revival of electric analogs for vibrating mechanical. A given electrical system consisting of resistance, inductance and capacitance may be analogous to the mechanical system consisting of a suitable combination of dashpot, mass, and spring. Since the energy of the mass in a mechanical 1 analogy is measured relative to mechanical ground i.
The velocity of the car doesnt change instantaneously, so it starts at zero, and follows a saturating exponential up to v0, with a time constant mb. The idea can be explained simply in terms of liftage. Aug 31, 2017 mechanical electrical analogy the concept of an analogous system is very useful in practice. The electromechanical analogy can be classified into two categories. Electric analogies to thermal systems physics forums. In this analogy, the mathematical equations of the rotational mechanical system are compared with the nodal mesh equations of the electrical system by comparing equation 4 and equation 6, we will get the analogous quantities of rotational mechanical system. This introduces analogies between the two forms of energy, which can be expressed in two. Electrons have no appreciable inertia while water does so it take a lot of energy to.
The capacitor is analogous to the spring in mechanical systems. Mathematical modelling of control system mechanical. Nov, 2015 understanding electricity with hydraulics november, 2015 by trevor gamblin the analogy between hydraulics and electricity is a useful tool for teaching and for those who are struggling to understand how circuits work. However, as electrical network analysis matured it was found that certain mechanical problems could more. Jan 30, 2019 mathematical modelling of control system there are various types of physical systems, namely we have. Friday 9 the electro mechanical analogy analogies occur throughout physics. These are summarized in the table below prepared by dr. Mechanical impedances in series must be combined as the reciprocal of the sum of the reciprocals while electrical impedances in series are additive. The force f in a mechanical system is analogous to the current i in an electrical system as shown in figure 2. The concept dog is one thing with all breeds being subsets and all individual dogs being elements of the same set. Similarly, there is a torque current analogy for rotational mechanical systems. In this, the charge on the capacitor, c, varies in time in the same way as the displacement of the mass on a spring.
Electrical circuit analogies for several engineering disciplines have been developed over time. Electromechanical analogies we will now represent the phenomena existing in mechanical systems, by an equivalent electrical network. Silvio alessandroni, francesco dellisola, maurizio porfiri. The analogy between electricity and hydraulics is good for understanding basic electricity but breaks down for many things. Explain the steps you use to find your electrical system. Page 2 teacher section water analogy to electric circuits behavioral objectives. A revival of electric analogs for vibrating mechanical systems aimed to their efficient control by pzt actuators silvio alessandroni, francesco dellisola, maurizio porfiri to cite this version. By usitng an analogy mechanics electricity system can be. Resistance r spring constant k elastance 1c external force ft electromotive force. Electrical analogy for 1d heat conduction by comparing the steady state heat flow equation with ohms law for current flow through a resistor, we see that they have similar forms, we can therefore draw the following analogies. Mechanicalelectrical analogies are used to represent the function of a mechanical system as an equivalent electrical system by drawing analogies between mechanical and electrical parameters. The same analytic method can be applied to electroacoustic analogies. Image courtesy of thinkstock mechanicalelectrical systems. The mechanical analogy used is the mobility analogy in which the physical analogies are sacrificed in favor of creating equivalent mathematical relationships which hold in network analysis.
Torque current analogy compares the mathematical equations of the rotational mechanical system with the nodal mesh equations of the electrical system. Mechanical electrical analogy the concept of an analogous system is very useful in practice. Learners read an analogy comparing mechanical work in this case, sliding a weight to that of electrical power. If i have, please feel free to request additional data. A diesel mechanic for more than 25 years, he has also been a boatbuilder, cabinetmaker, and machinist. James clerk maxwell introduced analogies of this sort in the 19th century.
On the contrary, they are separate and incompatible. The relationship of work, apparent work, and power factor is developed. A mechanical system by itself can be so represented, but analogies are of greatest use in electromechanical systems where there is a connection between. Materials used in the electrical analogy setup to develop flownets for various groundwater flow situations. Harvard university division of engineering and applied sciences.
Courses at engineering lecture notes, previous year questions and solutions pdf free download mechanical engineering mech, engineering class handwritten notes, exam notes, previous year questions, pdf free download. In the case of these analogies, the impedance analogy and the mobility analogy are not part of some greater theory we can call mechanical electrical analogy. Engs 22 systems system analogies page 2 m b vint frictionless fig. Indicate the values of all components in the electrical system resistors, capacitors, inductors, etc. The new analogy is derived from the similarity of the following equations. Analogy between electric and uid circuits dan styer a simple circuit e r i i i i electric circuit water flow circuit pump rapid plateau lowlevel flatland electric current coulombssec. A clearer conception of the analogies is pursued by treatment of hydraulic systems as distinct from mechanical systems, interpretation of acoustic as mixed mechanichydraulic systems, analysis of the operation of piston mechanisms, and consideration of gyroelements. Chapter 8 electrical and mechanical page 82 washington state bridge inspection manual m 3664. Friday 9 the electromechanical analogy analogies occur throughout physics.
Mechanicalelectrical analogies are the representation of mechanical systems as electrical networks. The proposed model was built from the mechanical description given by the paraschivoiu doublemultiple streamtube model and is based on the analogy between mechanical and electrical circuits. Mathematical modelling of control system there are various types of physical systems, namely we have. The inductor is the inertial term of the electrical circuit, and therefore the voltage drop is proportional to the derivative of the current.
Inside a box of polyurethane foam, a 60 w lightbulb is turned on. Analogy between mechanical and electrical systems mechanical springmass electric rlc system with damping series circuit mx. Live parts to which an employee may be exposed shall be deenergized before the employee works on or near them, unless. Induction motor electrical and mechanical angle electrical. The theory of mechanical systems leads to electrical results by applying the electricalmechanical analogy to the lrc circuit equation in current form with et e 0 sin.
We will also illustrate these principles with a few examples as well as provide some bibliography to more advanced references in electromechanics. The input vint is a step functionzero until the engine couples, and then at a constant velocity v0 thereafter. The force current analogy requires equations of steadystate energy storage phenomena while the constitutive equations of equilibrium force voltage analogy energy storage phenomena do not. Using analogy to enhance understanding of electrical circuits. In this analogy, the mathematical equations of the rotational mechanical system are compared with the nodal mesh equations of the electrical system. Mechanical electrical osha electrical standards 29 cfr 1910. Figures 1 and 2 demonstrate the situation and give the energy conservation equations for the ideal case with no losses to friction or resistance.
There is an incompleteness in the mechanical analogues of kirchhoffs laws. Since one type of system may be easier to handle experimentally than other. Upon completion of this lab a student should be able to. Find the analogous electrical system using the forcevoltage analogy. Mechanicalelectrical mechanicalelectrical systems developed by james mcglothlin, mph, ph.
How appropriate is it to use hydrodynamics analogy to. Jun 15, 2017 this is the reason for using a circuit analogy in a vibrating mechanical system. Craig 2 electrical mechanical analogies a signal, element, or system which exhibits mathematical behavior identicalto that of another, but physically different, signal, element, or system is called an analogous quantity or analog. Electrical analogies of mechanical systems in control. Using the model, we explain a basic principle of electricfield communication that uses the. Electrical analogies of mechanical systems tutorialspoint. Calder is the author of how to read a nautical chart, nigel calders cruising handbook, refrigeration for pleasureboats, and marine diesel engines. Teacher section water analogy to electric circuits behavioral objectives. When we talk about potential the analogy becomes less useful since we rarely discuss gravitational potential. A given electrical system consisting of resistance, inductance and capacitance may be analogous to the mechanical system consisting of a suitable combination of dashpot, mass.
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