<i>Dynamical Analogies</i>

Olson, Harry F.; Nostrand, Douglas Van; Balise, Peter L.

doi:10.1063/1.3060732

Cited by 30 publications

(34 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The Fourier transform (S,) is the weighted integral of the time-varying function x(t): fd So: = x (t) c2rdttd = A, + jBz, (1) where f = frequency at which the integral is evaluated, I = time in seconds, and j = I. A, and B, are the real and imaginary components of S, at frequency f, and contain magnitude and phase information of this frequency component of x(t).…”

Section: Methodsmentioning

confidence: 99%

“…The description of the respiratory system in terms of electrical analogs (1) by Otis et al (2) and others (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15), has facilitated solutions to many problems involving the dynamic behavior of the lungs and chest. Most authors, as a first approximation, have considered the resistive, inertial, and elastic properties of the respiratory system analogous to a simple series resistanceinductance-capacitance (RLC)1 electrical network or to a resistance-mass-spring mechanical system (3, 4, 9, 10 …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Pulmonary mechanics by spectral analysis of forced random noise.

Michaelson¹,

Grassman²,

Peters³

1975

J. Clin. Invest.

362

179

View full text Add to dashboard Cite

The magnitude (1Z,81) and phase angle (0r8) of the total respiratory impedance (Zr,), from 3 to 45 Hz, were rapidly obtained by a modification of the forced oscillation method, in which a random noise pressure wave is imposed on the respiratory system at the mouth and compared to the induced random flow using Fourier and spectral analysis. No significant amplitude or phase errors were introduced by the instrumentation. 10 normals, 5 smokers, and 5 patients with chronic obstructive lung disease (COPD) were studied. Measurements of Zr, were corrected for the parallel shunt impedance of the mouth, which was independently measured during a Valsalva maneuver, and from which the mechanical properties of the mouth were derived. There were small differences in Zr, between normals and smokers but both behaved approximately like a second-order system with 0r8 = 00 in the range of 5-9 Hz, and Or, in the range of +40°at 20 Hz and +60°at 40 Hz. In COPD, Or, remained more negative (compared to normals and smokers) at all frequencies and crossed 0 between 15 and 29 Hz. Changes in Zr,, similar to those in COPD, were also observed at low lung volumes in normals. These changes, the effects of a bronchodilator in COPD, and deviations of Zr, from second-order behavior in normals, can best be explained by a two-compartment parallel model, in which time-constant discrepancies between the lung parenchyma and compliant airways keep compliant greater than inertial reactance, resulting in a more negative phase angle as frequency is increased. INTRODUCTIONThe description of the respiratory system in terms of electrical analogs (1) by Otis et al. (2) and others (3-15),

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Pulmonary mechanics by spectral analysis of forced random noise.

Michaelson¹,

Grassman²,

Peters³

1975

J. Clin. Invest.

362

179

View full text Add to dashboard Cite

show abstract

“…Two valid techniques of modeling mechanical systems with electrical systems or drawing analogies between the two types of systems can found in the literature, with each method having its own advantages and disadvantages [50][51][52][53][54]. The first technique is intuitive; in this technique, current corresponds to velocity (both are motion), and voltage corresponds to force (both provide a "push").…”

Section: The Mechanical-electrical Analogy Approachmentioning

confidence: 99%

“…Both are valid. However, the through/across analogy results in a counterintuitive definition of impedance [49,51,52,55]. The analogy for impedance that is universally applied is the one from the intuitive analogy listed in the corresponding section of Table 2.…”

Section: The Mechanical-electrical Analogy Approachmentioning

confidence: 99%

A New Approach for Modeling Darrieus-Type Vertical Axis Wind Turbine Rotors Using Electrical Equivalent Circuit Analogy: Basis of Theoretical Formulations and Model Development

et al. 2015

View full text Add to dashboard Cite

Models are crucial in the engineering design process because they can be used for both the optimization of design parameters and the prediction of performance. Thus, models can significantly reduce design, development and optimization costs. This paper proposes a novel equivalent electrical model for Darrieus-type vertical axis wind turbines (DTVAWTs). The proposed model was built from the mechanical description given by the Paraschivoiu double-multiple streamtube model and is based on the analogy between mechanical and electrical circuits. This work addresses the physical concepts and theoretical formulations underpinning the development of the model. After highlighting the working principle of the DTVAWT, the step-by-step development of the model is presented. For assessment purposes, simulations of aerodynamic characteristics and those of corresponding electrical components are performed and compared.

show abstract

“…On the other hand, a voltage pulse is reflected with phase unchanged and hence has double amplitude at the end. If stress 01' force is taken as analogous to voltage and velocity analogous to current (Olson 1958), it may be concluded that the electrical analogue of a rod with free ends is a short-circuited transmission line. Similarly, the electrical analogue of a rod with clamped ends is an open-circuited transmission line.…”

Section: Acoustical Transmission-line Theory (A) Boundary Oonditmentioning

confidence: 99%

Resonant Behaviour of an Acoustical Transmission Line

Pollard¹

1962

Aust. J. Phys.

View full text Add to dashboard Cite

SummaryIn the passage of elastic waves through a cylindrical rod, phenomena are exhibited that closely resemble those occurring in an electromagnetic waveguide. Following a discussion of the classical Pochhammer-Chree theory for an infinite cylinder, elastic wave propagation in a finite rod is considered under conditions ~hen the rod may be regarded as analogous to an electrical transmission line. In the case of a resonant system, normal mode analysis provides a simplified treatment and it is shown that the results are in agreement with transmission-line theory. A brief discussion is given regarding the identity of the pulse response of a system and its response to continuous waves.

show abstract

Dynamical Analogies

Cited by 30 publications

References 0 publications

Pulmonary mechanics by spectral analysis of forced random noise.

Pulmonary mechanics by spectral analysis of forced random noise.

A New Approach for Modeling Darrieus-Type Vertical Axis Wind Turbine Rotors Using Electrical Equivalent Circuit Analogy: Basis of Theoretical Formulations and Model Development

Resonant Behaviour of an Acoustical Transmission Line

Contact Info

Product

Resources

About