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Author

Amir Nassirharand

Bio: Amir Nassirharand is an academic researcher from University of Nottingham Malaysia Campus. The author has contributed to research in topics: Nonlinear system & Describing function. The author has an hindex of 13, co-authored 56 publications receiving 442 citations. Previous affiliations of Amir Nassirharand include Shahid Beheshti University & Michigan Technological University.


Papers
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Journal ArticleDOI
TL;DR: The method and the associated software have no restriction on nonlinearity type, configuration, and arrangement, system order as well as the number of inputs and outputs; the only requirement is that system output for sinusoidal input must be obtainable or available by either simulation or experiments.

31 citations

Journal ArticleDOI
TL;DR: In this paper, a new dynamic and nonlinear simulation method for liquid-propellant engines is presented, and corresponding software for a particular engine is developed, and the logic of the simulation method and the software is based on following the liquid(s).
Abstract: A new dynamic and nonlinear simulation method for liquid-propellant engines is presented, and the corresponding software for a particular engine is developed. The logic of the simulation method and the software is based on following the liquid(s). The dynamic equations of motion are composed of implicit nonlinear algebraic equations, as well as nonlinear and time-varying differential equations. The implicit nonlinear algebraic equations are solved using a number of nested Newton-Raphson loops, and the nonlinear and time-varying differential equations are solved using a first-order Euler technique. The simulation results are compared with experimental results. The software language is FORTRAN, and it is composed of approximately 200 subroutines for a total of approximately 4000 lines.

28 citations

Journal ArticleDOI
TL;DR: The goal is to design an output feedback system that is a solution to a robust design such that sensitivity of the feedback control system with respect to amplitude of the excitation signal and the operating regimes would be at a minimum.

25 citations

Journal ArticleDOI
TL;DR: In this paper, a new approach for modeling a class of pressurization systems for liquid propellant engines is presented, where high pressure gas stored in special capsules is injected in a controlled way onto the gas volume on top of the propellant tanks.

22 citations


Cited by
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Journal ArticleDOI
TL;DR: An effective control method based on adaptive PID neural network and particle swarm optimization (PSO) algorithm is presented and an improved gradient descent method is introduced to adjust the network parameters.

96 citations

Proceedings ArticleDOI
11 Dec 1996
TL;DR: In this article, an automatic procedure for diagnosis of oscillations in control loops in a paper mill is presented, which is one of the features of a "control loop performance monitoring" (CLPM) system under development.
Abstract: We present an automatic procedure for diagnosis of oscillations in control loops in a paper mill. This procedure is one of the features of a "control loop performance monitoring" (CLPM) system under development, and works online without disturbing normal plant operation. When an oscillating control loop is detected, the diagnosis tools allow the determination of the cause of the oscillating behavior. It could be high friction in the control valve, a poorly tuned controller or the presence of an external perturbation.

52 citations

Journal ArticleDOI
TL;DR: In this paper, a computational fluid dynamic (CFD) model is introduced to simulate the pressurized discharge event of liquid hydrogen (LH2) tank, and the wall region together with the fluid region is simultaneously considered as the computational domain, and low-Re k-e model is applied to account for the fluid-wall heat exchange effect.

42 citations

Journal ArticleDOI
TL;DR: In this article, a computational fluid dynamic (CFD) model was constructed to investigate the transient thermal and pressurization performance of a cryogenic tank during discharge, which can simultaneously account for the heat exchanges inside the tank and outside aerodynamic heating.

38 citations

Journal ArticleDOI
TL;DR: The conceptual basis, main features and functionality of an interactive software tool developed in support of system identification education and discovery, developed using Sysquake, a Matlab-like language with fast execution and excellent facilities for interactive graphics, is described.

32 citations