scholarly journals Natural-Laminar-Flow Airfoil and Wing Design by Adjoint Method and Automatic Transition Prediction

2009 ◽  
Author(s):  
Jen-Der Lee ◽  
Antony Jameson
Keyword(s):  
Laminar Flow ◽  
Adjoint Method ◽  
Wing Design ◽  
Transition Prediction ◽  
Natural Laminar Flow

A Turbofan-Engine Nacelle Shape Design and Optimization Method for Natural Laminar Flow Control

2016 ◽  
Author(s):  
Songyang Li ◽  
Yongjian Zhong
Keyword(s):  
Laminar Flow ◽  
Drag Coefficient ◽  
Longitudinal Profile ◽  
Shape Design ◽  
Aerodynamic Shape ◽  
Optimization System ◽  
Transition Prediction ◽  
Profile Line ◽  
Natural Laminar Flow ◽  
Engine Nacelle

A correctly profiled engine nacelle can delay the transition in the boundary layer and allow laminar flow to extend back, resulting in a substantial drag reduction. Therefore, the laminar flow nacelle has lower fuel consumption than current turbulent designs. In this paper, aerodynamic shape optimization of natural laminar flow nacelle has been studied by using a novel nacelle shape design method and transition prediction with CFD. First, the 2D longitudinal profile-line of nacelle is optimized, in order to extend its laminar region and achieve minimum drag coefficient within the design space. Second, the optimized longitudinal profile-line is then circumferentially stacked to construct the 3D nacelle aerodynamic shape. At last, the aerodynamic improvement of the new shape is evaluated by 3D CFD simulation. A nacelle geometry generator has been developed where the deflection angle (related to the curvature) along the cord is controlled by using Non-Uniform Rational B-Splines. It is then analytically integrated to obtain the longitudinal profile-line. And also a leading edge matching function is involved in the generator. This technique improves the smoothness of nacelle profile-line, which ensures the curvature and slope of curvature to be continuous all over the nacelle surface. The pressure distribution over the nacelle surface has been improved with no spikes in Mach number. A transition model coupling with shear stress transport turbulent model is used in solving Navier-Stokes equations for transition prediction. An optimization system has been established in combination with the geometry generator, the transition prediction model with CFD, a Kriging surrogate model and a Multi-Island Genetic Algorithm. As a result, the aerodynamic improvement, with one profile-line optimized, is obvious against the original nacelle shape by CFD validation in 3D simulation. The optimized nacelle can achieve a laminar flow up to 23% and its drag coefficient has reduced by 6.5%. It is indicated that the optimization system is applicable in nacelle aerodynamic shape design.

Supercritical natural laminar flow airfoil optimization for regional aircraft wing design

2015 ◽  
Vol 43 ◽  
pp. 152-164 ◽  
Author(s):  
Yufei Zhang ◽  
Xiaoming Fang ◽  
Haixin Chen ◽  
Song Fu ◽  
Zhuoyi Duan ◽  
...  
Keyword(s):  
Laminar Flow ◽  
Wing Design ◽  
Aircraft Wing ◽  
Airfoil Optimization ◽  
Natural Laminar Flow

Supersonic Natural-Laminar-Flow Wing-Design Concept at High-Reynolds-Number Conditions

AIAA Journal ◽  
2014 ◽  
Vol 52 (6) ◽  
pp. 1294-1306 ◽  
Author(s):  
Yoshine Ueda ◽  
Kenji Yoshida ◽  
Kisa Matsushima ◽  
Hiroaki Ishikawa
Keyword(s):  
Reynolds Number ◽  
Laminar Flow ◽  
High Reynolds Number ◽  
Design Concept ◽  
Wing Design ◽  
Natural Laminar Flow ◽  
High Reynolds
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