A New Approach to the Simulation of Thermal Systems

2005 ◽  
Vol 128 (3) ◽  
pp. 161-167 ◽  
Author(s):  
Nedim Sözbir
Keyword(s):  
Linear System ◽  
Linear Equations ◽  
Taylor Series Expansion ◽  
Equation System ◽  
Thermal System ◽  
Thermal Systems ◽  
Suggested Approach ◽  
New Approach ◽  
Linear System Of Equations ◽  
System Equations

In this paper, thermal systems are simulated and analyzed with a new approach. Thermal system design equations can be obtained as a nonlinear algebraic equation system and then this nonlinear equation system is converted to a well-defined or non-well-defined linear equation system. The transformation of the nonlinear system equations to linear system equations is realized by using the first-order Taylor series expansion; after that, the linear system of equations of our thermal system is obtained. These linear equations are then solved by our new suggested approach. This new algorithm and conventional solution methods are applied for designing some thermal systems, such as the heat exchangers combination and the gas turbine plant using design calculations. Obtained conventional and new approach results for those samples of thermal systems are compared and interpreted.

FUZZY CENTRE BASED SOLUTION OF FUZZY COMPLEX LINEAR SYSTEM OF EQUATIONS

2013 ◽  
Vol 21 (04) ◽  
pp. 629-642 ◽  
Author(s):  
DIPTIRANJAN BEHERA ◽  
S. CHAKRAVERTY
Keyword(s):  
Linear Time ◽  
Linear Equations ◽  
Electric Circuit ◽  
System Of Linear Equations ◽  
New Approach ◽  
Linear System Of Equations ◽  
Linear Time Invariant ◽  
Complex Linear ◽  
Time Invariant ◽  
Good Agreement

A new approach to solve Fuzzy Complex System of Linear Equations (FCSLE) based on fuzzy complex centre procedure is presented here. Few theorems related to the investigation are stated and proved. Finally the presented procedure is used to analyze an example problem of linear time invariant electric circuit with complex crisp coefficient and fuzzy complex sources. The results obtained are also compared with the known solutions and are found to be in good agreement.

scholarly journals An Analytical Method for Generating Determined Torque Ripple in Synchronous Machine with Interior Magnets by Harmonic Current Injection

Machines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 62
Author(s):  
Matthias Vollat ◽  
Junchao Li ◽  
Frank Gauterin
Keyword(s):  
Analytical Method ◽  
Electromotive Force ◽  
Equation System ◽  
Torque Ripple ◽  
Synchronous Machines ◽  
System Of Equations ◽  
Linear System Of Equations ◽  
Harmonic Currents ◽  
System Equations ◽  
Phase Angles

In this paper, we present an extension for an analytical method of calculating the required amplitudes and phase angles of the injected harmonic currents, to generate a determined torque ripple for synchronous machines. With the consideration of reluctance torque in the system equations, this method is valid not only for synchronous machines with surface magnets, but also for those with interior magnets. First, we describe the machine equations as a function of the phase current and the back electromotive force. We then introduce an analytical way to calculate the reluctance torque. After combining the equations, we establish a linear system of equations. The solution of the equation system yields the amplitudes and phase angles of the harmonic currents to be injected. Finally, we validate the equations for calculating the reluctance Torque and the method to generate the determined torque ripple with several finite element method simulations. This allowed us to generate the desired torque fluctuations even for synchronous machines with interior magnets.

Energy Principles and Finite Element Methods for Pure Traction Linear Elasticity

2011 ◽  
Vol 11 (2) ◽  
pp. 173-191 ◽  
Author(s):  
Pavel Bochev ◽  
Richard Lehoucq
Keyword(s):  
Finite Element ◽  
Linear System ◽  
Potential Energy ◽  
Linear Equations ◽  
Iterative Solution ◽  
Point Of View ◽  
Energy Principle ◽  
Element Discretization ◽  
Linear System Of Equations ◽  
Solution Algorithms

AbstractA conforming finite element discretization of the pure traction elasticity boundary value problem results in a singular linear system of equations. The singularity of the linear system is removed through various approaches. In this report, we consider an alternative approach in which discrete finite element formulations are derived directly from the principle of minimum potential energy. This point of view turns out to be particularly well suited to handle the rigid body modes, which are the source of the singularity in the finite element linear system. Our approach allows us to formulate a regularized potential energy principle and show that the associated weak problem is coercive in H1(Ω). This guarantees nonsingular problems, enables simplified solution algorithms and leads to more efficient and robust preconditioners for the iterative solution linear equations.

scholarly journals A NEW APPROACH TO DYNAMIC FINITE-SIZE SCALING

2003 ◽  
Vol 14 (07) ◽  
pp. 945-954 ◽  
Author(s):  
MEHMET DİLAVER ◽  
SEMRA GÜNDÜÇ ◽  
MERAL AYDIN ◽  
YİĞİT GÜNDÜÇ
Keyword(s):  
Three Dimensional ◽  
Finite Size ◽  
Taylor Series Expansion ◽  
Scaling Behavior ◽  
Dynamic Scaling ◽  
Finite Size Scaling ◽  
New Approach ◽  
Size Scaling ◽  
Dynamic Exponent ◽  
Good Agreement

In this work we have considered the Taylor series expansion of the dynamic scaling relation of the magnetization with respect to small initial magnetization values in order to study the dynamic scaling behavior of two- and three-dimensional Ising models. We have used the literature values of the critical exponents and of the new dynamic exponent x0 to observe the dynamic finite-size scaling behavior of the time evolution of the magnetization during early stages of the Monte Carlo simulation. For the three-dimensional Ising model we have also presented that this method opens the possibility of calculating z and x0 separately. Our results show good agreement with the literature values. Measurements done on lattices with different sizes seem to give very good scaling.

An efficient approach to the seismogram synthesis for a basin structure using propagation invariants

1996 ◽  
Vol 86 (2) ◽  
pp. 379-388 ◽  
Author(s):  
H. Takenaka ◽  
M. Ohori ◽  
K. Koketsu ◽  
B. L. N. Kennett
Keyword(s):  
Integral Equation ◽  
Inverse Fourier Transform ◽  
Linear Equations ◽  
Computation Time ◽  
Reduction Technique ◽  
Final Solution ◽  
Space Domain ◽  
New Approach ◽  
Simultaneous Linear Equations ◽  
Single Integral

Abstract The Aki-Larner method is one of the cheapest methods for synthetic seismograms in irregularly layered media. In this article, we propose a new approach for a two-dimensional SH problem, solved originally by Aki and Larner (1970). This new approach is not only based on the Rayleigh ansatz used in the original Aki-Larner method but also uses further information on wave fields, i.e., the propagation invariants. We reduce two coupled integral equations formulated in the original Aki-Larner method to a single integral equation. Applying the trapezoidal rule for numerical integration and collocation matching, this integral equation is discretized to yield a set of simultaneous linear equations. Throughout the derivation of these linear equations, we do not assume the periodicity of the interface, unlike the original Aki-Larner method. But the final solution in the space domain implicitly includes it due to use of the same discretization of the horizontal wavenumber as the discrete wavenumber technique for the inverse Fourier transform from the wavenumber domain to the space domain. The scheme presented in this article is more efficient than the original Aki-Larner method. The computation time and memory required for our scheme are nearly half and one-fourth of those for the original Aki-Larner method. We demonstrate that the band-reduction technique, approximation by considering only coupling between nearby wavenumbers, can accelerate the efficiency of our scheme, although it may degrade the accuracy.

Computer Simulation for Active Control of Vibration in Beam Structures

1995 ◽  
Author(s):  
Masa. Tanaka ◽  
T. Matsumoto ◽  
L. Huang
Keyword(s):  
Inverse Problem ◽  
Active Control ◽  
Inverse Analysis ◽  
Taylor Series Expansion ◽  
Integral Equation Method ◽  
Unknown Parameters ◽  
Bending Vibration ◽  
Linear System Of Equations ◽  
Elastic Beams ◽  
The Laplace Transform

Abstract This paper is concerned with an inverse problem of the active control of non-steady dynamic vibration in elastic beams. A simulation technique based on the boundary element method and the extended Kalman filter or a new filter theory is successfully applied to the inverse problem. The Laplace-transform integral equation method is used for the solution of dynamic bending vibration in elastic beams. Through a Taylor series expansion, the linear system of equations is derived for modification of the unknown parameters, and it is solved iteratively so that an appropriate norm is minimized. The usefulness of the proposed method of inverse analysis is demonstrated through numerical computation of a few examples.

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