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Rathay N.W.,Rensselaer Polytechnic Institute | Rathay N.W.,Boeing Company | Boucher M.J.,Boeing Company | Amitay M.,Mechanical | Whalen E.,Boeing Company
50th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition | Year: 2012

Active flow control with synthetic jets has been shown to increase aerodynamic efficiency by delaying flow separation. Application of flow control to a vertical stabilizer of an aircraft could enable a significant size reduction of that stabilizer. Wind tunnel experiments were conducted at Rensselaer Polytechnic Institute on a swept back, tapered stabilizer with a 33% chord rudder. Flow control was implemented using eight synthetic jet actuators located just upstream of the hinge-line. The mechanism of enhancement was characterized with surface pressure measurements and stereoscopic particle image velocimetry (SPIV). Using flow control, the side force was increased by up to 20% at moderate rudder deflections with actuators operating at dimensionless frequency O(10). Actuating the synthetic jets with a pulse-modulated waveform yielded superior performance at high rudder deflections. The effect of spanwise spacing was also investigated, as was the relative effect of actuators at different spanwise locations. It was demonstrated that mid-span actuators provide the greatest contribution at moderate rudder deflections, and root (inboard) actuators provide the greatest contribution a high deflections. Given that separation propagates from tip to root as rudder deflection increases, this correlates well with SPIV measurements, which show that the effect of each actuator is predominantly on a region outboard of its own position. Copyright © 2012 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved. Source

Sreenivasulu A.,Mechanical | Venkatachalapathi N.,Velammal Engineering College | Prasanthi G.,P.A. College
Journal of Advanced Manufacturing Systems | Year: 2015

The aim of this paper is to deal with a simulation study on effect of part launching, part sequencing at central buffer and tool selection rules on a flexible manufacturing system (FMS) involving tool movement along with part movement policy. A typical FMS is selected for a study of discrete event simulation model. Simulation experiments are conducted on various combinations of decision rules and it is found to be good in evaluated performance measures. © 2015 World Scientific Publishing Company. Source

Huang H.,University of Tennessee at Knoxville | Ekici K.,Mechanical
AIAA Journal | Year: 2014

We investigate the application of a temporal spectral viscosity operator to eliminate aliasing errors associated with the high-dimensional harmonic balance technique, which is an efficient method for modeling nonlinear time-periodic problems. Previous studies have shown that aliasing errors resulting from the discrete Fourier transformation may slow down convergence, trigger a nonlinear instability, or lead to nonphysical solutions. A temporal spectral viscosity operator, similar to that used for pseudospectral methods, is introduced. The temporal spectral viscosity is added to the high-frequency modes of the solution to eliminate aliasing errors so as to ensure the convergence to the physical solution. The implementation of the technique is straightforward and can be incorporated into the high-dimensional harmonic balance solver as a matrix product operator. The accuracy and effectiveness of the modified method is demonstrated for different test cases including a Duffing oscillator and unsteady flow about an oscillating circular cylinder. Finally, the temporal spectral viscosity is applied to a turbomachinery aeroelasticity problem to investigate the effect of added dissipation on the accuracy of unsteady solutions. Copyright © 2013 by Huang Huang and Kivanc Ekici. Source

Linze N.,Boulevard Dolez | Tihon P.,Mechanical | Verlinden O.,Mechanical | Megret P.,Boulevard Dolez | Wuilpart M.,Boulevard Dolez
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2012

In this paper we propose a novel kind of quasi-distributed polarimetric vibration sensor. Its functioning is based on the use of mechanical transducers, which transform the mechanical vibration into a birefringence variation, and of fiber Bragg gratings (FBGs), which reflect light from different positions. As it will be shown this sensor can provide the vibration frequency in a quasi-distributed manner. © 2012 SPIE. Source

Vande Cavey M.,Mechanical | Helsen L.,Mechanical | Tant J.,ESAT | Geth F.,ESAT | Driesen J.,ESAT
IET Conference Publications | Year: 2013

This paper presents real-time control strategies for peak shaving and voltage control provided by a Battery Energy Storage System in a low voltage grid. Two performance indices, one for peak shaving and one for voltage control, are proposed to quantify the results. The strategies are compared with a benchmark which is calculated as an ex post optimization that solves the control problem together with the sizing problem. First, a rule-based strategy for peak shaving is presented which only injects active power. Afterwards, the strategy is extended with voltage control through reactive power injection. In the latter case, an optimization problem is solved at each time step to decide at which rate active and reactive power should be injected. Source

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