Silvio alessandroni, francesco dellisola, maurizio porfiri. It will be shown that the conventional me chanical electrical analogy is incomplete in certain important par. The capacitor is analogous to the spring in mechanical systems. However, we need to be cautious and keep safety in mind.
Engs 22 systems system analogies page 2 m b vint frictionless fig. Image courtesy of thinkstock mechanicalelectrical systems. Previously weve used a relatively adhoc approach to come up with mechanical models and their electrical equivalents. Analogies between mechanical and electrical systems have obtained quite some. In this article i will describe a more systematic approach that can be used to analyze mechanical systems alone, or combined electromechanical systems together. Mechanicalelectrical analogies are the representation of mechanical systems as electrical networks. The mechanical analogy used is the mobility analogy in which the physical analogies are sacrificed in favor of creating equivalent mathematical.
Since the energy of the mass in a mechanical 1 analogy is measured relative to mechanical ground i. The input vint is a step functionzero until the engine couples, and then at a constant velocity v0 thereafter. At first, such analogies were used in reverse to help. Electrical analogies of mechanical systems tutorialspoint. Electrical quantity, mechanical analog i forcecurrent, mechanical analog ii force voltage. The advantage of doing this is that there is a large body of theory and analysis techniques concerning complex electrical systems, especially in the field of filters. The design of the mechanical services must take into account the site microclimate, the building form and orientation of spaces, the thermal performance.
Heat conduction in solids is similar to the conduction of electricity in electrical conductors in many aspects. Mechanical and electrical plant and equipment is located at basement and ground levels of the imaging centre, at basement and lower ground levels of sydney street extension, and at main roof plant levels on both the sydney street extension and existing sydney wing. Similarly, there is a torque current analogy for rotational mechanical systems. Insidepenton com electronic design adobe pdf logo tiny. Another important benefit is that this model preserves enough of the mechanical details that mechanical systems can easily be cascaded as well see in the examples. Mechanical quantity symbol electrical quantity symbol mass m inductance l. The analogy revolves around a deceptively simple mental image, and as a teacher this is the time to have some fun. While that approach works for simple systems, it quickly becomes errorprone. They possess greater mechanical strength, longer life and permit longer spans to be used. At first, such analogies were used in reverse to help explain electrical phenomena in familiar mechanical terms. This analogy has the advantage that it enables a circuit diagram of the electrical model to be copied from the diagram of the mechanical system, if this is drawn. Friday 9 the electro mechanical analogy analogies occur throughout physics. But this is a drivethrough bank and cars travelling through pick up one jewel from each vault. Understanding electricity with hydraulics technical articles.
Analogy between mechanical and electrical systems mechanical springmass electric rlc system with damping series circuit mx. Weaver, facility manager, birck nanotechnology center. The idea can be explained simply in terms of liftage. Indicate the values of all components in the electrical system resistors, capacitors, inductors, etc. The performance analysis and improvement of heat transfer processes are common problems in hens design, which offers a huge potential for energy. Mechanical electrical analogy the concept of an analogous system is very useful in practice. You may do so in any reasonable manner, but not in.
Electromechanical analogies direct analogy indirect analogy 14 simple mechanical system 16 analogy comparison 17 a. Whether your background is electrical or mechanical, analogies exist between the. The inductor is the inertial term of the electrical circuit, and therefore the voltage drop is proportional to the derivative of the current. Electrical analogies of mechanical systems in control. Find the analogous electrical system using the forcevoltage analogy. A textbook on mechanical and electrical engineering. Resistance r spring constant k elastance 1c external force ft electromotive force. Imagine a bank with one or more vaults, each containing a supply of jewels. This introduces analogies between the two forms of energy, which can be expressed in two. Finally, the description here can easily be adopted for other electromechanical devices than motors. The new analogy is derived from the similarity of the following equations. James clerk maxwell introduced analogies of this sort in the 19th century.
Harvard university division of engineering and applied sciences. 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. Using analogies to explain electrical relationships. 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. When we talk about potential the analogy becomes less useful since we rarely discuss gravitational potential. An electrical interpretation of mechanical systems via the pseudo. Electro mechanical analogies we will now represent the phenomena existing in mechanical systems, by an equivalent electrical network. 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. Electromechanical analogies we will now represent the phenomena existing in mechanical systems, by an equivalent electrical network.
We will also illustrate these principles with a few examples as well as provide some bibliography to more advanced references in electromechanics. There is a very close analogy between mechanical and electrical motion. Analogy of hydraulic, mechanical, acoustic and electric. Electrical analogies of mechanical systems in control systems electrical analogies of mechanical systems in control systems courses with reference manuals and examples pdf. 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. Electro mechanical analogies direct analogy indirect analogy 14 simple mechanical system 16 analogy comparison 17 a. Hydraulicspneumatics com sites hydraulicspneumatics com files uploads 2014. To apply this analogy, every node in the electrical circuit becomes a point in the mechanical system. The same analytic method can be applied to electroacoustic analogies. Analogies between mechanical systems and electrical and fluid systems, however, do work well and are in common use. Mechanicalelectrical mechanicalelectrical systems developed by james mcglothlin, mph, ph.
In this analogy, the mathematical equations of the rotational mechanical system are compared with the nodal mesh equations of the electrical system. Using analogy to enhance understanding of electrical circuits. Since the energy of the mass in a mechanical 2 analogy is measured relative to a fixed reference i. 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. By converting to an electrical representation, these tools in the electrical domain can be directly applied to a mechanical. A revival of electric analogs for vibrating mechanical. The key to solving an analogy question is to precisely describe the relationship between the pair of words and then apply the same relationship to determine which word completes the analogy.
It is analogous to the viscous friction element of mechanical system. Aug 31, 2017 mechanical electrical analogy the concept of an analogous system is very useful in practice. A mechanical system by itself can be so represented, but analogies are of greatest use in electromechanical systems where there is a connection between. Pdf active vibration control using mechanical and electrical. 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. Using the model, we explain a basic principle of electricfield communication that uses the. Such poles are generally used for distribution purposes in the cities. The design of the mechanical services must take into account the site microclimate, the building form and orientation of. Mechanical impedances in series must be combined as the reciprocal of the sum of the reciprocals while electrical impedances in series are additive. This type of supports need to be galvanized or painted in order to prolong its life. Analogy teaching method, hydraulic components, electrical components.
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. Electric potential is more commonly known as voltage and for uniform fields. The force f in a mechanical system is analogous to the current i in an electrical system as shown in figure 2. 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. Chapter 8 electrical and mechanical page 82 washington state bridge inspection manual m 3664. Electrical circuit analogy for heat transfer analysis and. Flowmeters are mostly mechanical devices that can be calibrated with. 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. 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. Pdf mechanicalelectrical analogous circuit models are widely used in electromechanical system design as they represent the function of a. These analogies are used to analyze the non electrical system like mechanical system from. Electrical analogy of heat conduction heat conduction in solids is similar to the conduction of electricity in electrical conductors in many aspects. I microphones, loudspeakers consist of mechanical, acoustical and electrical subsystems i due to their interaction an analysis has to consider all subsystems in integral way i the fundamental di erential equations have identical form in all systems i introduction of analogies and conversion of mechanical and acoustical systems into electrical ones. Since one type of system may be easier to handle experimentally than other.
Analogous electrical and mechanical systems swarthmore college. These are summarized in the table below prepared by dr. There is an incompleteness in the mechanical analogues of kirchhoffs laws. Most analogy questions rely on your ability to deduce the correct relationship between words and to draw logical conclusions about the possible answer. Next, power dissipation of the forced, simple springmass system will be discussed in order to. 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.
Jun, 2005 the new analogy is derived from the similarity of the following equations. 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. To apply this analogy, every loop in the electrical circuit becomes a point in the mechanical system. By usitng an analogy mechanics electricity system can be represented according from mechanical 203 at akademia ekonomiczna w poznaniu. Jun 15, 2017 this is the reason for using a circuit analogy in a vibrating mechanical system. Safety tips have all electrical work done by a qualified electrician. The impedance analogy is a method of representing a mechanical system by an analogous electrical system. In this way, a resistor dissipates electrical energy into. The electromechanical analogy can be classified into two categories. Harvard university division of engineering and applied. Friday 9 the electromechanical analogy analogies occur throughout physics. This introduces analogies between the two forms of. Heat exchanger network hen, a necessary subsystem, is widely applied in most energy utilization systems, ranging from heating, ventilation and air conditioning system, thermal management system, to petrochemical industry. Electrical and mechanical chapter 8 washington state bridge inspection manual m 3664.
Here we discussed the electrical analogies of the mechanical 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. 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. An open electrical switch blocks current, whereas a closed switch conducts. An analogous electrical and mechanical system will have differential equations of the same form. Mathematical modelling of control system mechanical. Hydraulicspneumatics com sites hydraulicspneumatics com files uploads 2014 04 hp table.
Mechanical and electrical building services engineering. The electro mechanical analogy can be classified into two categories. However, as electrical network analysis matured it was found that certain mechanical problems could more. By usitng an analogy mechanics electricity system can be. Materials used in the electrical analogy setup to develop flownets for various groundwater flow situations. Many quantities that we use to describe mechanical motion have an analog in electrical motion. Explain the steps you use to find your electrical system. Hydraulicspneumatics com sites hydraulicspneumatics com files uploads 2014 05 0614. Analogy between a hydraulic circuit left and an electrical circuit right. Electrical circuit analogies for several engineering disciplines have been developed over time. 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.
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