The Experts below are selected from a list of 5883 Experts worldwide ranked by ideXlab platform
E. Egusquiza - One of the best experts on this subject based on the ideXlab platform.
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Application of Rotor Response Analysis to fault detection in hydro powerplants.
Hydraulic Machinery and Cavitation, 1996Co-Authors: L. P. Nascimento, E. EgusquizaAbstract:In this article some considerations obtained during the utilization of Rotor Response Analysis tecniques in hydraulic powerplants are discussed. An applied research work was carried out in two hydraulic turbines analysing the Rotor Response both theoretically and experimentally. A developed mathematical model was used to simulate the Rotordynamic behaviour of Francis and Kaplan turbines. The main dynamical effects that appear during the operation of the machines are discussed too. A series of measurements were carried out in the turbines using impact hammers to determine the modal behaviour of the units. The tests were carried out with the machine still and in operation. Some results and the comparison with the theory is presented in this article. The improved theoretical model was used for a sensitivity Analysis of the different bearings to the main excitations that take place during the machine operation. From this Analysis, the best measuring points for condition monitoring were determined.
L. P. Nascimento - One of the best experts on this subject based on the ideXlab platform.
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Application of Rotor Response Analysis to fault detection in hydro powerplants.
Hydraulic Machinery and Cavitation, 1996Co-Authors: L. P. Nascimento, E. EgusquizaAbstract:In this article some considerations obtained during the utilization of Rotor Response Analysis tecniques in hydraulic powerplants are discussed. An applied research work was carried out in two hydraulic turbines analysing the Rotor Response both theoretically and experimentally. A developed mathematical model was used to simulate the Rotordynamic behaviour of Francis and Kaplan turbines. The main dynamical effects that appear during the operation of the machines are discussed too. A series of measurements were carried out in the turbines using impact hammers to determine the modal behaviour of the units. The tests were carried out with the machine still and in operation. Some results and the comparison with the theory is presented in this article. The improved theoretical model was used for a sensitivity Analysis of the different bearings to the main excitations that take place during the machine operation. From this Analysis, the best measuring points for condition monitoring were determined.
Jonathan Keller - One of the best experts on this subject based on the ideXlab platform.
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Validation and Application of a Transient Aeroelastic Analysis for Shipboard Engage/Disengage Operations.
1996Co-Authors: William P. Geyer, Edward C. Smith, Jonathan KellerAbstract:Abstract : A previously developed transient aeroelastic Rotor Response Analysis for shipboard engage/disengage sequences is utilized in the present research. The blade has elastic flap and torsion degrees of freedom and the equations of motion are discretized using the finite element method. The discretized equations of motion are integrated for a specified Rotor speed run-up or run-down profile. Blade element theory is used to calculate quasi-steady or unsteady aerodynamic loads in linear and nonlinear regimes. Three deterministic wind gust distributions can be used to model the ship air wake environment. This Analysis is modified to include a flap stop which restrains upper flap motion and a flap damper which damps flap hinge motion. In addition, an arbitrary gust model is incorporated into the Analysis to enable more realistic airwake models. Validation studies are conducted using experimental data collected from a ship/helicopter model placed in a wind tunnel. Theoretical prediction show good agreement with experimental data for windward hub locations on the deck. A study of the effectiveness and feasibility of a flap damper placed at the flap hinge is conducted. It indicates that a flap damper is an effective and feasible method to reduce downward tip deflections for an H-46 if the flap stop angle is raised. One study of the effects of pilot controllable parameters shows that the H-46 throttle advancement rate reduces the maximum downward tip deflections for spatially varying gusts.
William P. Geyer - One of the best experts on this subject based on the ideXlab platform.
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Validation and Application of a Transient Aeroelastic Analysis for Shipboard Engage/Disengage Operations.
1996Co-Authors: William P. Geyer, Edward C. Smith, Jonathan KellerAbstract:Abstract : A previously developed transient aeroelastic Rotor Response Analysis for shipboard engage/disengage sequences is utilized in the present research. The blade has elastic flap and torsion degrees of freedom and the equations of motion are discretized using the finite element method. The discretized equations of motion are integrated for a specified Rotor speed run-up or run-down profile. Blade element theory is used to calculate quasi-steady or unsteady aerodynamic loads in linear and nonlinear regimes. Three deterministic wind gust distributions can be used to model the ship air wake environment. This Analysis is modified to include a flap stop which restrains upper flap motion and a flap damper which damps flap hinge motion. In addition, an arbitrary gust model is incorporated into the Analysis to enable more realistic airwake models. Validation studies are conducted using experimental data collected from a ship/helicopter model placed in a wind tunnel. Theoretical prediction show good agreement with experimental data for windward hub locations on the deck. A study of the effectiveness and feasibility of a flap damper placed at the flap hinge is conducted. It indicates that a flap damper is an effective and feasible method to reduce downward tip deflections for an H-46 if the flap stop angle is raised. One study of the effects of pilot controllable parameters shows that the H-46 throttle advancement rate reduces the maximum downward tip deflections for spatially varying gusts.
Edward C. Smith - One of the best experts on this subject based on the ideXlab platform.
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Validation and Application of a Transient Aeroelastic Analysis for Shipboard Engage/Disengage Operations.
1996Co-Authors: William P. Geyer, Edward C. Smith, Jonathan KellerAbstract:Abstract : A previously developed transient aeroelastic Rotor Response Analysis for shipboard engage/disengage sequences is utilized in the present research. The blade has elastic flap and torsion degrees of freedom and the equations of motion are discretized using the finite element method. The discretized equations of motion are integrated for a specified Rotor speed run-up or run-down profile. Blade element theory is used to calculate quasi-steady or unsteady aerodynamic loads in linear and nonlinear regimes. Three deterministic wind gust distributions can be used to model the ship air wake environment. This Analysis is modified to include a flap stop which restrains upper flap motion and a flap damper which damps flap hinge motion. In addition, an arbitrary gust model is incorporated into the Analysis to enable more realistic airwake models. Validation studies are conducted using experimental data collected from a ship/helicopter model placed in a wind tunnel. Theoretical prediction show good agreement with experimental data for windward hub locations on the deck. A study of the effectiveness and feasibility of a flap damper placed at the flap hinge is conducted. It indicates that a flap damper is an effective and feasible method to reduce downward tip deflections for an H-46 if the flap stop angle is raised. One study of the effects of pilot controllable parameters shows that the H-46 throttle advancement rate reduces the maximum downward tip deflections for spatially varying gusts.
