The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform
Silviu-iulian Niculescu - One of the best experts on this subject based on the ideXlab platform.
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On the stability of linear systems with uncertain delay
IEEE Transactions on Automatic Control, 2003Co-Authors: V.l. Kharitonov, Silviu-iulian NiculescuAbstract:This note focuses on the stability of some class of delay systems, including uncertainty in the delays. More precisely, we are interested in guaranteeing the stability of perturbed delay systems by assuming the stability of the nominal system. If the delay perturbation is Constant, necessary and sufficient conditions are derived in terms of generalized eigenvalue distribution of some (finite-Dimensional) Constant matrix pencil. If the delay perturbation is time-varying, some sufficient stability conditions are derived using "exact" Lyapunov-Krasovskii functionals. Illustrative examples are also included.
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On the stability of linear systems with uncertain delay
2002Co-Authors: V.l. Kharitonov, Silviu-iulian NiculescuAbstract:This paper focuses on the stability of some class of delay systems including uncertainty in the delays. More precisely, we are interested in guaranteeing the stability of perturbed delay systems by assuming the stability of the nominal system. If the delay perturbation is Constant, necessary and sufficient conditions are derived in terms of generalized eigenvalue distribution of some (finite-Dimensional) Constant matrix pencil. If the delay perturbation is time-varying, some sufficient stability conditions are derived using 'exact' Lyapunov-Krasovskii functionals.
V.l. Kharitonov - One of the best experts on this subject based on the ideXlab platform.
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On the stability of linear systems with uncertain delay
IEEE Transactions on Automatic Control, 2003Co-Authors: V.l. Kharitonov, Silviu-iulian NiculescuAbstract:This note focuses on the stability of some class of delay systems, including uncertainty in the delays. More precisely, we are interested in guaranteeing the stability of perturbed delay systems by assuming the stability of the nominal system. If the delay perturbation is Constant, necessary and sufficient conditions are derived in terms of generalized eigenvalue distribution of some (finite-Dimensional) Constant matrix pencil. If the delay perturbation is time-varying, some sufficient stability conditions are derived using "exact" Lyapunov-Krasovskii functionals. Illustrative examples are also included.
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On the stability of linear systems with uncertain delay
2002Co-Authors: V.l. Kharitonov, Silviu-iulian NiculescuAbstract:This paper focuses on the stability of some class of delay systems including uncertainty in the delays. More precisely, we are interested in guaranteeing the stability of perturbed delay systems by assuming the stability of the nominal system. If the delay perturbation is Constant, necessary and sufficient conditions are derived in terms of generalized eigenvalue distribution of some (finite-Dimensional) Constant matrix pencil. If the delay perturbation is time-varying, some sufficient stability conditions are derived using 'exact' Lyapunov-Krasovskii functionals.
J. Dey - One of the best experts on this subject based on the ideXlab platform.
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Laminar-turbulent transition modelling at IISc
Journal of the Indian Institute of Science, 2013Co-Authors: J. Dey, O. N. Ramesh, M Jahanmiri, S V S Phani Kumar, A. PrabhuAbstract:An overview of laminar-turbulent transition zone modelling research at IISc is presented. The linear combination model based on the principle of combining mean laminar and turbulent profiles in proportions determined by the interminency has been found to provide an excellent representation of the transition zone in two-Dimensional incompressible boundary-layer flows. Ongoing investigations in a three-Dimensional Constant pressure flow with lateral Streamline divergence indicate that many transitional characteristics are similar to those in two- Dimensional Constant pressure flows for modelling purposes.
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Transition zone in Constant pressure converging flows
2000Co-Authors: Kp Vasudevan, J. DeyAbstract:The effect of lateral streamline convergence alone on the transitional flow characteristics has been studied towards modelling the transition zone. Apart from a thicker boundary layer, the transitional flow characteristics are found to be similar to those in two-Dimensional Constant pressure flows. The transition zone has been modeled using the linear-combination model for two Dimensional flows.
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Transitional intermittency distribution pressure diverging flow in a three-Dimensional Constant
1996Co-Authors: O. N. Ramesh, J. Dey, A. PrabhuAbstract:Intermittency measurements are made in the transition-zone of a three-Dimensional Constant pressure diverging flow in order to study the effect of lateral strain rate on the intermittency distribution. Measured intermittency data are found to follow the two-Dimensional behaviour thus indicating that the lateral strain rate does not affect the normalised intermittency distribution in the transition zone.
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Transitional intermittency distribution in a three-Dimensional Constant pressure diverging flow
Experiments in Fluids, 1996Co-Authors: O. N. Ramesh, J. Dey, A. PrabhuAbstract:Intermittency measurements are made in the transition-zone of a three-Dimensional Constant pressure diverging flow in order to study the effect of lateral strain rate on the intermittency distribution. Measured intermittency data are found to follow the two-Dimensional behaviour thus indicating that the lateral strain rate does not affect the normalised intermittency distribution in the transition zone.
R. C. Sutcliffe - One of the best experts on this subject based on the ideXlab platform.
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Surface resistance in atmospheric flow
Quarterly Journal of the Royal Meteorological Society, 2007Co-Authors: R. C. SutcliffeAbstract:The formula for surface resistance to atmospheric flow, F = ρκV2s, where Vs is the velocity of the surface wind, ρ the density, and κ a non-Dimensional Constant, was proposed by G. I. Taylor, on an analogy with flow in pipes. In pipes, the value of κ was 0.004, and Taylor gave a mean value of 0.0025 for κ in the case of flow of air over the ground. In this paper the value of κ was deduced from actual observed distributions of wind velocity at different heights, obtained by pilot balloons, no assumption being made as to the nature of eddy viscosity. The mean value of κ so deduced is 0.006 over land, and 0.0004 over the sea.
A. Prabhu - One of the best experts on this subject based on the ideXlab platform.
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Laminar-turbulent transition modelling at IISc
Journal of the Indian Institute of Science, 2013Co-Authors: J. Dey, O. N. Ramesh, M Jahanmiri, S V S Phani Kumar, A. PrabhuAbstract:An overview of laminar-turbulent transition zone modelling research at IISc is presented. The linear combination model based on the principle of combining mean laminar and turbulent profiles in proportions determined by the interminency has been found to provide an excellent representation of the transition zone in two-Dimensional incompressible boundary-layer flows. Ongoing investigations in a three-Dimensional Constant pressure flow with lateral Streamline divergence indicate that many transitional characteristics are similar to those in two- Dimensional Constant pressure flows for modelling purposes.
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Transitional intermittency distribution pressure diverging flow in a three-Dimensional Constant
1996Co-Authors: O. N. Ramesh, J. Dey, A. PrabhuAbstract:Intermittency measurements are made in the transition-zone of a three-Dimensional Constant pressure diverging flow in order to study the effect of lateral strain rate on the intermittency distribution. Measured intermittency data are found to follow the two-Dimensional behaviour thus indicating that the lateral strain rate does not affect the normalised intermittency distribution in the transition zone.
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Transitional intermittency distribution in a three-Dimensional Constant pressure diverging flow
Experiments in Fluids, 1996Co-Authors: O. N. Ramesh, J. Dey, A. PrabhuAbstract:Intermittency measurements are made in the transition-zone of a three-Dimensional Constant pressure diverging flow in order to study the effect of lateral strain rate on the intermittency distribution. Measured intermittency data are found to follow the two-Dimensional behaviour thus indicating that the lateral strain rate does not affect the normalised intermittency distribution in the transition zone.