Generalization of the Far-Field Drag Decomposition Method to Unsteady Flows

AIAA Journal ◽  
2013 ◽  
Vol 51 (6) ◽  
pp. 1309-1319 ◽  
Author(s):  
Martin Gariepy ◽  
Jean-Yves Trepanier ◽  
Benoit Malouin
Keyword(s):  
Decomposition Method ◽  
Unsteady Flows ◽  
Far Field

Far-Field Drag Prediction and Decomposition Method for Unsteady Flows

2011 ◽  
Author(s):  
Martin Gariepy ◽  
Jean-yves Trepanier ◽  
Benoit Malonin ◽  
Christian Masson
Keyword(s):  
Decomposition Method ◽  
Unsteady Flows ◽  
Far Field ◽  
Drag Prediction

scholarly journals Development and Application of a New Unsteady Far-Field Drag Decomposition Method

AIAA Journal ◽  
2015 ◽  
Vol 53 (11) ◽  
pp. 3414-3429 ◽  
Author(s):  
Hélène Toubin ◽  
Didier Bailly
Keyword(s):  
Decomposition Method ◽  
Far Field

Convergence Criterion for a Far-Field Drag Prediction and Decomposition Method

AIAA Journal ◽  
2011 ◽  
Vol 49 (12) ◽  
pp. 2814-2818 ◽  
Author(s):  
Martin Gariépy ◽  
Jean-Yves Trépanier ◽  
Christian Masson
Keyword(s):  
Decomposition Method ◽  
Convergence Criterion ◽  
Far Field ◽  
Drag Prediction

scholarly journals Numerical Solution of Riccati Equations by the Adomian and Asymptotic Decomposition Methods over Extended Domains

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Jafar Biazar ◽  
Mohsen Didgar
Keyword(s):  
Decomposition Method ◽  
Near Field ◽  
Adomian Decomposition Method ◽  
Approximate Solutions ◽  
Riccati Equations ◽  
Decomposition Methods ◽  
Field Approximation ◽  
Far Field ◽  
Asymptotic Decomposition ◽  
Adomian Decomposition

We combine the Adomian decomposition method (ADM) and Adomian’s asymptotic decomposition method (AADM) for solving Riccati equations. We investigate the approximate global solution by matching the near-field approximation derived from the Adomian decomposition method with the far-field approximation derived from Adomian’s asymptotic decomposition method for Riccati equations and in such cases when we do not find any region of overlap between the obtained approximate solutions by the two proposed methods, we connect the two approximations by the Padé approximant of the near-field approximation. We illustrate the efficiency of the technique for several specific examples of the Riccati equation for which the exact solution is known in advance.

Far-Field Drag Decomposition Method Applied to the DPW-5 Test Case Results

2013 ◽  
Author(s):  
Martin Gariepy ◽  
Benoit Malouin ◽  
Jean-Yves Trepanier ◽  
Eric Laurendeau
Keyword(s):  
Decomposition Method ◽  
Test Case ◽  
Far Field

Direct Computations of Unsteady Flows About Thin Airfoils

1998 ◽  
Vol 06 (03) ◽  
pp. 337-355 ◽  
Author(s):  
Sheryl M. Grace ◽  
S. I. Hariharan ◽  
Hafiz M. Atassi
Keyword(s):  
Numerical Scheme ◽  
Unsteady Flows ◽  
Computational Approach ◽  
Far Field ◽  
Asymptotic Results ◽  
Linearized Euler Equations ◽  
High Order Schemes ◽  
Complete Study ◽  
Instantaneous Pressure ◽  
Low Order

The intent of this paper is to investigate the effectiveness of direct numerical computation in capturing acoustic fields. It has been the trend to use high-order schemes whenever there is interest in resolving the acoustic field, even though there has never been a complete study of the accuracy of low-order schemes. We revisit a long-standing benchmark problem in aeroacoustics to show the validity of such low-order schemes. The problem we consider is that of a flat-plate airfoil in a non-uniform flow. We show that when the linearized Euler equations are used to model problems in aeroacoustics, a simple second-order numerical scheme is powerful enough to provide accurate aeroacoustic results. We validate this computational approach by comparing both the RMS and instantaneous pressure on the airfoil and in the far field to semianalytic and asymptotic results.

scholarly journals Aerodynamic Design and Shape Optimization with the Far-Field Drag Decomposition Approach

2020 ◽  
Vol 38 (3) ◽  
pp. 558-570
Author(s):  
Li Li ◽  
Junqiang Bai ◽  
Xiaolong He
Keyword(s):  
Shape Optimization ◽  
Axial Velocity ◽  
Decomposition Method ◽  
Far Field ◽  
Aerodynamic Shape Optimization ◽  
Decomposition Approach ◽  
Total Drag ◽  
Velocity Defect ◽  
Aerodynamic Shape ◽  
Drag Prediction

In the aerodynamic shape design, the drag prediction has always been an extremely challenging mission for the exploration of a configuration. As for the more complex configurations, it is especially desired to the availability of a highly accurate and reliable aerodynamic numerical solution. For improving the drag prediction accuracy and promoting the aerodynamic shape designs, firstly, the characteristics of drag prediction based on far-field drag method and near-field drag method is analyzed and compared. Also, the merits and demerits of defining axial velocity defect with the current main far-field drag prediction approaches is summarized, which promotes the building of the improved method of axial velocity defect and the improved far-field drag prediction and decomposition approach. Moreover, during the establishment of the drag decomposition method, it is necessary to judge and decide on the selection of the drag region. Therefore, the discussions on the sensitivity of the relevant parameters are fulfilled. Furthermore, based on the far-field drag prediction and decomposition method constructed, the aerodynamic performance research of Common Research Model wing-body configuration is launched. The results show that it can effectively observe and analyze the changes in drag components, their impact on the total drag and the contribution percentage. Finally, combining the far-field drag prediction and decomposition method proposed in this paper with a gradient-based aerodynamic shape optimization design system, the aerodynamic shape optimization designs are studied with CRM wing-body configuration. The results can not only directly analyze the detailed change of the visualized drag region, but also can obtain the more accurate total drag and lift-to-drag ratio of the optimized configuration by removing the spurious drag.

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