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121.
122.
A numerical solution is obtained for the steady oblique stagnation-point flow of a micropolar fluid over a stretching or shrinking surface with velocity slip condition. Results are obtained for representative values of slip parameter, micropolar parameter and stretching/shrinking parameter for strong particle interaction micropolar fluid. Dual solutions are found for the case of shrinking surface. An analysis of stability of these dual solutions shows that the solution branch that proceeds to large stretching case is stable. The streamlines are not symmetric for the oblique stagnation-point flow and reversed flow are observed near to the shrinking surface. The streamlines plots show that increase of slip parameter will reduce/eliminate the existing of rotating flow near the surface that caused by the shrinking effect. 相似文献
123.
Ioan Bica 《Journal of magnetism and magnetic materials》2004,270(3):321-326
The magnetorheological suspension (MRS) brake is of the monoblock type. The main part of the electromagnetic brake is an electromagnet, between whose poles two MRS disks are placed. For distances between disks of 0.65×10−3 m±10%, revolutions of the electric motor, coupled to the electromagnetic brake, ranging between 200 and 1600 rev/min and braking powers of up to 85 W, there are no differences in revolutions between the disks of the electromagnetic brake. For fixed revolutions of the electric motor, the revolution of the parallel disk can be modified continuously by means of the intensity of the magnetic field. In all cases, the quantity of MRS is of 0.35×10−3 kg. 相似文献
124.
The aim of this paper is to implement some new techniques, based on conjugate duality in convex optimization, for proving the existence of global error bounds for convex inequality systems. First of all, we deal with systems described via one convex inequality and extend the achieved results, by making use of a celebrated scalarization function, to convex inequality systems expressed by means of a general vector function. We also propose a second approach for guaranteeing the existence of global error bounds of the latter, which meanwhile sharpens the classical result of Robinson. 相似文献
125.
The work presents theoretical and experimental investigations concerning the neuro-fuzzy control of electrohydraulic servos. The control algorithm is built around a neurocontroller designed to optimize a performance index. Whenever the neurocontrol saturates or a system performance parameter decreases, the control scheme switches to a feasible and reliable fuzzy logic control. In accordance with simulation studies developed in previous works of the authors, the neuro-fuzzy controlled system proves often to be better than the corresponding classical PI or LQG systems. We emphasize that the entire control synthesis is thought as a model free approach, thus ensuring reduced design complexity and focusing on increased system robustness. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
126.
M. S. Malashetty Ioan Pop Rajashekhar Heera 《Continuum Mechanics and Thermodynamics》2009,21(4):317-339
Double diffusive convection in a fluid-saturated rotating porous layer is studied when the fluid and solid phases are not
in local thermal equilibrium, using both linear and nonlinear stability analyses. The Brinkman model that includes the Coriolis
term is employed as the momentum equation. A two-field model that represents the fluid and solid phase temperature fields
separately is used for the energy equation. The onset criterion for stationary, oscillatory, and finite amplitude convection
is derived analytically. It is found that small inter-phase heat transfer coefficient has significant effect on the stability
of the system. There is a competition between the processes of thermal diffusion, solute diffusion, and rotation that causes
the convection to set in through either oscillatory or finite amplitude mode rather than stationary. The effect of solute
Rayleigh number, porosity modified conductivity ratio, Lewis number, diffusivity ratio, Vadasz number, and Taylor number on
the stability of the system is investigated. The nonlinear theory based on the truncated representation of Fourier series
method predicts the occurrence of subcritical instability in the form of finite amplitude motions. The effect of thermal non-equilibrium
on heat and mass transfer is also brought out. Some of the convection systems previously reported in the literature is shown
to be special cases of the system presented in this study. 相似文献
127.
The aim of this Letter is to show that, the Nusselt number sign might be changed without changing of heat transfer direction at the wall of channels, even for flows without viscous dissipation. 相似文献
128.
We give sufficient conditions for the rigid body in the presence of an axisymmetric force field and a gyroscopic torque to admit a Hamilton-Poisson formulation. Even if by adding a gyroscopic torque we initially lose one of the conserved Casimirs, we recover another conservation law as a Casimir function for a modified Poisson structure. We apply this frame to several well-known results in the literature. 相似文献
129.
130.