Evaluation of CFD methods for transport aircraft high lift systems

2005 ◽  
Vol 109 (1092) ◽  
pp. 53-64 ◽  
Author(s):  
R. Rudnik ◽  
P. Eliasson ◽  
J. Perraud

Abstract Major results and findings of the numerical work package of the European high lift programme EUROLIFT are outlined. The main objective of these studies is to validate and test numerical methods for the prediction of high lift flows for transport aircraft configurations. The activities comprise the assessment of current CFD methods for 3D flows, evaluation of means for code improvement, and transition prediction. All aspects are especially devoted to high lift flow problems. A general capability to predict maximum lift on a simplified wing/fuselage high lift configuration is demonstrated by a variety of different numerical approaches. In general, major shortcomings are the reliability and the accurate simulation of large separation areas and the turn-around time to compute 3D lift polars. Advanced turbulence modelling and numerical solver features, such as the preconditioning technique, show a potential to overcome these deficiencies. Promising results with respect to transition prediction were obtained on a swept high lift wing using a database method. The results obtained in the numerical activities represent major ingredients on the way to a consistent numerical approach for the simulation of transport aircraft high lift configurations including all maximum lift determining effects.

2008 ◽  
Vol 45 (5) ◽  
pp. 1554-1563 ◽  
Author(s):  
J. Perraud ◽  
J. Cliquet ◽  
R. Houdeville ◽  
D. Arnal ◽  
F. Moens

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yonghu Wang ◽  
Ray C. Chang ◽  
Wei Jiang

Purpose The purpose of this paper is to present a quick inspection method based on the post-flight data to examine static aeroelastic behavior for transport aircraft subjected to instantaneous high g-loads. Design/methodology/approach In the present study, the numerical approach of static aeroelasticity and two verified cases will be presented. The non-linear unsteady aerodynamic models are established through flight data mining and the fuzzy-logic modeling of artificial intelligence techniques based on post-flight data. The first and second derivatives of flight dynamic and static aeroelastic behaviors, respectively, are then estimated by using these aerodynamic models. Findings The flight dynamic and static aeroelastic behaviors with instantaneous high g-load for the two transports will be analyzed and make a comparison study. The circumstance of turbulence encounter of the new twin-jet is much serious than that of four-jet transport aircraft, but the characteristic of stability and controllability for the new twin-jet is better than those of the four-jet transport aircraft; the new twin-jet transport is also shown to have very small aeroelastic effects. The static aeroelastic behaviors for the two different types can be assessed by using this method. Practical implications As the present study uses the flight data stored in a quick access recorder, an intrusive structural inspection of the post-flight can be avoided. A tentative conclusion is to prove that this method can be adapted to examine the static aeroelastic effects for transport aircraft of different weights, different sizes and different service years in tracking static aeroelastic behavior of existing different types of aircraft. In future research, one can consider to have more issues of other types of aircraft with high composite structure weight. Originality/value This method can be used to assist airlines to monitor the variations of flight dynamic and static aeroelastic behaviors as a complementary tool for management to improve aviation safety, operation and operational efficiency.


2004 ◽  
Vol 41 (6) ◽  
pp. 1384-1392 ◽  
Author(s):  
M. R. Malik ◽  
R.-S. Lin

2001 ◽  
Vol 38 (6) ◽  
pp. 1076-1084 ◽  
Author(s):  
C. P. van Dam ◽  
J. C. Vander Kam ◽  
J. K. Paris

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
D. Roubinet ◽  
S. Demirel ◽  
E. B. Voytek ◽  
X. Wang ◽  
J. Irving

Modeling fluid flow in three-dimensional fracture networks is required in a wide variety of applications related to fractured rocks. Numerical approaches developed for this purpose rely on either simplified representations of the physics of the considered problem using mesh-free methods at the fracture scale or complex meshing of the studied systems resulting in considerable computational costs. Here, we derive an alternative approach that does not rely on a full meshing of the fracture network yet maintains an accurate representation of the modeled physical processes. This is done by considering simplified fracture networks in which the fractures are represented as rectangles that are divided into rectangular subfractures such that the fracture intersections are defined on the borders of these subfractures. Two-dimensional analytical solutions for the Darcy-scale flow problem are utilized at the subfracture scale and coupled at the fracture-network scale through discretization nodes located on the subfracture borders. We investigate the impact of parameters related to the location and number of the discretization nodes on the results obtained, and we compare our results with those calculated using reference solutions, which are an analytical solution for simple configurations and a standard finite-element modeling approach for complex configurations. This work represents a first step towards the development of 3D hybrid analytical and numerical approaches where the impact of the surrounding matrix will be eventually considered.


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