Development of an automatic differentiation version of the FPX rotor code
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Development of an automatic differentiation version of the FPX rotor code

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Published by Hampton University, National Aeronautics and Space Administration, National Technical Information Service, distributor in Hampton, Va, [Washington, DC], [Springfield, Va .
Written in English


  • Computational fluid dynamics.,
  • Differentiators.,
  • Rotary wings.,
  • Finite difference theory.,
  • Grid generation (Mathematics),
  • Applications programs (Computers),
  • Rotor dynamics

Book details:

Edition Notes

Statementby Hong Hu.
Series[NASA contractor report] -- NASA CR-202194.
ContributionsUnited States. National Aeronautics and Space Administration.
The Physical Object
Pagination1 v.
ID Numbers
Open LibraryOL18121750M

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Automatic differentiation provides a simple computational method to obtain an arbitrary number of terms of the Taylor series solution of a system of differential equations y ' =f(x,y) at x=x 1. Adjoint code development benefits greatly from using Automatic Differentiation but at its current state of maturity, this technology is best applied selectively rather than on entire codes. Automatic Differentiation in Nuclear System Modeling Derivatives used for: – Source transformation; forward mode (reverse under development) – New version () based on industrial strength compiler infrastructure (potential for automatic code to outperform hand coding) Simplified climate model (importance of reverse mode and. 3 Automatic differentiation helps in keeping the linearised version of the nonlinear codes in-sync with the continuous changes made in the nonlinear code. The Jacobian obtained by this method is.

  The purpose of this book is to give a basic understanding of rotor dynamics phenomena with the help of simple rotor models and subsequently, the modern analysis methods for real life rotor systems. This background will be helpful in the identification of rotor-bearing system parameters and its use in futuristic model-based condition monitoring. The power of automatic differentiation is that it can deal with complicated structures from programming languages like conditions and loops. However, if all you need is algebraic expressions and you have good enough framework to work with symbolic representations, it's possible . Standard 3 phase motors often have these locked rotor codes: less than 1 hp: Locked Rotor Code L, - kVA; 1 1/2 to 2 hp: Locked Rotor Code L or M, - kVA; 3 hp: Locked Rotor Code K, - kVA; 5 hp: Locked Rotor Code J, - kVA; to 10 hp: Locked Rotor Code H, - . other hand, if the rotor bars are placed deeper into the rotor surface, there will be more leakage and the rotor reactance X2 will be larger. For example, Figure 7–25ais a photograph of a rotor lamination showing the cross section of the bars in the rotor. The rotor bars in the figure are quite large and are placed near the surface of the rotor.

  Today I will try to explain how the forward and backward mode in automatic differentiation work. I will only cover the principle, not actual algorithms and the optimizations they apply. While the so called forward mode is quite intuitive, it is not so easy to wrap your head around the backward mode. I will try. Version History; BibTeX {C. Bischof and G. Corliss and L. Green and A. Griewank and K. Haigler and P. Newman}, title = {Automatic Differentiation Of Advanced CFD Codes For Multidisciplinary Design} advanced cfd code multidisciplinary design automatic differentiation Powered by: About CiteSeerX. The Rotor Fault Zone refers to the condition of the rotor bars, rotor laminations, and end rings. Although only a small percentage of the motor problems, rotor faults can influence other fault zones to fail. This article from PdMA covers the Rotor Fault Zone in better detail. Gang Sheng Chen, Xiandong Liu, in Friction Dynamics, Modification of System Stiffness. The stiffness of a rotor system, defining its natural frequencies, is determined by the stiffness of the shaft, the stiffness of the pedestal, and the stiffness of the bearings and the rotor occasionally makes contact with the stator, the new boundary conditions modify its stiffness.