1) La descarga del recurso depende de la página de origen
2) Para poder descargar el recurso, es necesario ser usuario registrado en Universia


Opción 1: Descargar recurso

Opción 2: Descargar recurso

Detalles del recurso

Descripción

This study seeks to understand the interplay of vorticity and elasto-dynamics that forms the basis for a fluttering flag and flapping wing propulsion, and factors that distinguish one from the other. The fluid dynamics is assumed two dimensional and incompressible, and comprises potential and viscous flow simulations. The elastic solid is one dimensional and governed by the Bernoulli-Euler flexure model. The fluid and elastic solid models are coupled using a predictor-corrector algorithm. Flutter of a flag or foil is associated with drag and we show that the pressure on the foil is predominantly circulatory in origin. The circulatory pressure generated on the foil depends primarily on the slope and curvature. The wake vorticity exhibits a wide range of behavior starting from a Kelvin-Helmholtz type instability to a von Kármán wake. Potential flow simulations do not capture the wake accurately both at high and low mass ratios. This is reflected in the flutter boundary and pressure over the foil when compared with viscous flow simulations. Thrust due to heaving of a flexible foil shows maxima at a set of discrete frequencies that coincide with the frequencies at which the flapping velocity of the foil tip is a maximum. The propulsive efficiency shows maxima at a set of discrete frequencies that are close but distinct from the thrust maxima set of frequencies. These discrete frequencies are close to the natural frequencies of vibration of a cantilevered foil vibrating in vacuum. At low frequencies thrust is a consequence of a strong leading edge vortex developed over the foil and it remains attached to the foil as it is convected due to the favorable pressure gradient presented by the time and spatially varying shape of the foil. At moderate and high frequencies of oscillation the pressure, and consequently the thrust, generated by the foil is non-circulatory in origin and they are high where the accelerations of the foil are high. At high frequencies the leading edge vortex is weak. Except in the low frequency range, potential flow simulations qualitatively compares well with viscous flow predictions. We show that thrust and drag on a flexible foil oscillating in a flow is caused by the phase difference between the slope of the foil and the fluid pressure on it. Propulsive efficiency though is governed by the phase difference between foil velocity and fluid pressure and inertia forces. Thus, the interplay of vorticity and elasto-dynamics determine the behavior of a flutter and propulsion of a flexible foil in a fluid flow.

Pertenece a

ETD at Indian Institute of Science  

Autor(es)

Mysa, Ravi Chaithanya - 

Id.: 70125712

Idioma: inglés (Estados Unidos)  - 

Versión: 1.0

Estado: Final

Palabras claveWing Propulsion - 

Tipo de recurso: Thesis  - 

Tipo de Interactividad: Expositivo

Nivel de Interactividad: muy bajo

Audiencia: Estudiante  -  Profesor  -  Autor  - 

Estructura: Atomic

Coste: no

Copyright: sí

Requerimientos técnicos:  Browser: Any - 

Relación: [References] G26380

Fecha de contribución: 10-ene-2018

Contacto:

Localización:

Otros recursos que te pueden interesar

  1. Growth and age study of Pacific hagfish (Eptatretus stoutii) off the central California coast The recent development of a short term, but very intense fishery for Pacific hagfish (Eptatretus sto...
  2. New records of trematode parasites (Digenea) in the banded frog (Rana camerani) and marsh frog (Rana ridibunda ridibunda) (Anura: Ranidae), from southwest of Iran Fourteen adult frogs including six banded frog, Rana camerani and eight marsh frog, Rana ridibunda r...
  3. Distribution and biomass of macrobenthic fauna in the Chabahar Bay (North Eastern Sea of Oman) Population density, distribution and biomass of macrobenthic fauna in Chabahar Bay were investigated...
  4. Effect of chemical herbicides and insecticides on mortality and feeding of silver carp (Hypophthalmichthys molitrix) Fingerlings of Silver Carp (Hypophthalmichthys molitrix) were used in an ecotoxicological investigat...
  5. A preliminary study on fecundity of fresh water crayfish (Astacus leptodactylus) in Arass water reservoir, I.R. Iran A research study was conducted to investigate the number of ovarian eggs and estimate potential egg ...

Otros recursos de la mismacolección

  1. Inverse Problems in Free Vibration Analysis of Rotating and Non-Rotating Beams and its Application to Random Eigenvalue Characterization Rotating and non-rotating beams are widely used to model important engineering struc-tures. Hence, t...
  2. On Three Dimensional High Lift Flow Computations Computing 3D high lift flows has been a challenge to the CFD community because of three important re...
  3. A Study of the Characteristics of Gas-On-Liquid Impinging Injectors The work presented here pertains to investigations on gas-on-liquid type of impinging injectors with...
  4. Flutter Susceptibility Assessment of Airplanes in Sub-critical Regime using Ameliorated Flutter Margin and Neural Network Based Methods As flight flutter testing on an airplane progresses to high dynamic pressures and high Mach number r...
  5. Molecular Simulation of Anisotropic Stress and Structure in polymers This dissertation presents a numerical study using molecular dynamic simulations that interrogates t...

Aviso de cookies: Usamos cookies propias y de terceros para mejorar nuestros servicios, para análisis estadístico y para mostrarle publicidad. Si continua navegando consideramos que acepta su uso en los términos establecidos en la Política de cookies.