Ali Ashrafizadeh; A. A. Hosseinjani
Volume 7, Issue 2 , September 2010, , Pages 107-122
Abstract
The classical panel method has been extensively used in external aerodynamics to calculate ideal flow fields around moving vehicles or stationary structures in unbounded domains. However, the panel method, as a somewhat simpler implementation of the boundary element method, has rarely been employed to ...
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The classical panel method has been extensively used in external aerodynamics to calculate ideal flow fields around moving vehicles or stationary structures in unbounded domains. However, the panel method, as a somewhat simpler implementation of the boundary element method, has rarely been employed to solve problems in closed complex domains. This paper aims at filling this gap and discusses the numerical solution of the Laplace equation in bounded domains via the numerical panel method. It is shown that the panel method is an efficient and accurate computational algorithm for the solution of this class of problems. Several test cases in heat conduction and internal ideal flow are presented to show that the numerical panel method can be used in closed domains regardless of the complexities in the geometry and/or boundary conditions.
S.A. Sina; Hassan Haddad Pour
Volume 5, Issue 4 , December 2008, , Pages 180-182
Abstract
Two 2-D aeroelastic models are presented here to determine instability boundary (flutter speed) and gust response of a typical section airfoil with degrees of freedom in pitch and plunge directions. To build these 2-D aeroelastic models, two different aerodynamic theories including Indicial Aerodynamic ...
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Two 2-D aeroelastic models are presented here to determine instability boundary (flutter speed) and gust response of a typical section airfoil with degrees of freedom in pitch and plunge directions. To build these 2-D aeroelastic models, two different aerodynamic theories including Indicial Aerodynamic Theory and Vortex Lattice Method (VLM) have been employed. Also, a 3-D aeroelastic framework constructed of Boundary Element Method (BEM) and modal technique is used to show the accuracy and reliability of the presented 2-D aeroelastic models. The methods reviewed in this study are used to predict the non-dimensional flutter speed and its corresponding frequency for a typical section airfoil (for the 3-D model a high aspect ratio wing with the same cross-sectional characteristics is used) Then, a group of figures show how different time-marching schemes can change the dynamic responses due to the sharp edge gust. Also, a set of figures provide some comparisons between the 2-D aeroelastic models, and also, with the 3-D model. As seen from the results presented in this study 2-D aeroelastic models give lower non-dimensional flutter speed than the 3-D model. In addition, the dynamic responses due to the sharp edge gust predicted by the 2-D models show larger amplitudes than the 3-D model. It means that since the 2-D aeroelastic models can overestimate the dynamical behavior such as flutter speed and responses to the sharp edge gust, they can be used in the preliminary design steps to reduce the cost and save time.