Development of a Wing Section Design Code Including Inviscid/Viscous Interaction

2012 ◽  
Author(s):  
Christoph Michael Steinbach ◽  
Stefan Krueger
Keyword(s):  
Boundary Layer ◽  
Turbulent Flows ◽  
Inviscid Flow ◽  
Momentum Equation ◽  
Navier Stokes ◽  
Computational Time ◽  
Wing Section ◽  
Layer Method ◽  
Boundary Layer Method ◽  
Section Design

For wing design purposes the value of maximum lift angle is an important quantity. At the high Reynolds Numbers in naval architecture flows the onset and development of turbulent separation is the deciding value for the maximum lift angle. For the calculation of separated turbulent flows usually fully viscous flow solvers, like e.g. Reynolds averaged Navier Stokes (RANS) Solvers, are used. Instead of this kind of solvers, which are expensive by means of computational time, also interacting boundary layer (IBL) methods can be used. Due to the viscous-inviscid coupling, these methods are able to compute flows with limited separation up to the maximum lift angle and represent a cheap and robust alternative to higher value viscous solvers. In this paper a turbulent boundary layer method solving the integral momentum equation together with the integral energy equation of the boundary layer in an inverse formulation is described. The method is combined with an existing inviscid flow solver for 2D wing section flows and a laminar boundary layer method code including transition forecast.

scholarly journals ANALYSIS OF THREE WING SECTIONS

Aviation ◽  
2009 ◽  
Vol 13 (1) ◽  
pp. 3-10 ◽  
Author(s):  
Eduardas Lasauskas ◽  
Laurynas Naujokaiti
Keyword(s):  
Inviscid Flow ◽  
Measured Data ◽  
Sharp Drop ◽  
Displacement Effect ◽  
Laminar Separation ◽  
Wing Section ◽  
Empirical Correction ◽  
Layer Method ◽  
University Of Technology ◽  
Boundary Layer Method

Three wing sections FX66-S-196VI, E603 and AH82–150A were analyzed. Measured data of these wing sections are published. First wing section was measured in Stuttgart University and in Delft University of Technology, when other two wing sections were measured in Stuttgart University. These wing sections have different behavior in the region of maximum lift. FX66‐S‐196VI wing section has sharp drop in lift. The stall of the second and third wing sections is smooth, though different. All wing sections are affected by laminar separation bubbles. The calculations were performed using three codes: Eppler Program System, XFOIL and RFOIL. Eppler's code uses non‐interacted inviscid plus boundary layer method. Influence of separation is estimated using empirical correction in this method. XFOIL code of Mark Drela, MIT uses interacted zonal viscous/inviscid method. The wall transpiration model in this code approximates the displacement effect on the outer inviscid flow. RFOIL is a modification of XFOIL code for application in wind turbines performed at Delft University of Technology. The code's prediction of the airfoil performance around the two dimensional maximum lift was enhanced. The comparison of calculated and measured data is presented and analyzed. Santrauka Tyrimuose analizuotos profiliu FX 66-S-196 V1, E603 ir AH82–150A charakteristiku teorines reikšmes, apskaičiuotos XFOIL, RFOIL ir PROFIL05 programomis. Gautos teorines reikšmes palygintos su jau atliktu eksperimentiniu tyrinejimu rezultatais. Pirmas profilis buvo tyrinejamas Delft technologijos universitete (Olandija) ir Štutgarto universitete (Vokietija), like du ‐ Štutgarto universitete. Visi profiliai turi skirtingas maksimalios keliamosios jegos dalis. Profilio FX 66‐S‐196 V1 keliamoji jega mažeja staiga. Kitu profiliu keliamoji jega kinta tolygiai, tačiau skirtingai. Visu profiliu ucharakteristikas itakoja laminarinis atsiskyrimo burbulas.

Comparison of the Triple-Deck Theory, Interactive Boundary Layer Method, and Navier-Stokes Computation for Marginal Separation

1994 ◽  
Vol 116 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Chao-Tsung Hsiao ◽  
Laura L. Pauley
Keyword(s):  
Boundary Layer ◽  
Separation Bubble ◽  
Physical Phenomenon ◽  
Navier Stokes ◽  
Gradient Distribution ◽  
Layer Method ◽  
Boundary Layer Method ◽  
Incompressible Boundary ◽  
Layer Flow ◽  
Comparison Of The Results

The steady two-dimensional marginal separation of an incompressible boundary layer flow within a channel was solved independently by three different methods: the triple-deck method of marginal separation, the interactive boundary layer method, and the full Navier-Stokes computation. From comparison of the results between these three methods, the accuracy and appropriateness of each method was determined. The critical condition beyond which the steady marginal separation solution of triple-deck method does not exist was related to a physical phenomenon in which the separation bubble becomes unsteady. Factors such as Reynolds number and pressure gradient distribution which might influence the accuracy of the marginal separation solution were also investigated.

Essential Ingredients for the Computation of Steady and Unsteady Blade Boundary Layers

1991 ◽  
Vol 113 (4) ◽  
pp. 608-616 ◽  
Author(s):  
H. M. Jang ◽  
J. A. Ekaterinaris ◽  
M. F. Platzer ◽  
T. Cebeci
Keyword(s):  
Boundary Layer ◽  
Boundary Layers ◽  
Stokes Equations ◽  
Inviscid Flow ◽  
Reynolds Numbers ◽  
Navier Stokes ◽  
Transitional Region ◽  
Low Reynolds Numbers ◽  
Flow Equations ◽  
Low Reynolds

Two methods are described for calculating pressure distributions and boundary layers on blades subjected to low Reynolds numbers and ramp-type motion. The first is based on an interactive scheme in which the inviscid flow is computed by a panel method and the boundary layer flow by an inverse method that makes use of the Hilbert integral to couple the solutions of the inviscid and viscous flow equations. The second method is based on the solution of the compressible Navier–Stokes equations with an embedded grid technique that permits accurate calculation of boundary layer flows. Studies for the Eppler-387 and NACA-0012 airfoils indicate that both methods can be used to calculate the behavior of unsteady blade boundary layers at low Reynolds numbers provided that the location of transition is computed with the en method and the transitional region is modeled properly.

Boundary layer method in the problem of far propagation of surface SV-waves

2011 ◽  
Vol 175 (6) ◽  
pp. 651-671
Author(s):  
N. Ya. Kirpichnikova ◽  
A. S. Kirpichnikova
Keyword(s):  
Boundary Layer ◽  
Layer Method ◽  
Boundary Layer Method

A Simple and Robust Subsonic Boundary Layer Method to Be Used with the Panel Method for Wing Calculations Using a Wing Strip Approach

2015 ◽  
Vol 798 ◽  
pp. 596-601
Author(s):  
R.F. Francisco Reis ◽  
Guilherme A. Santana ◽  
Paulo Iscold ◽  
Carlos A. Cimini
Keyword(s):  
Boundary Layer ◽  
Lift Coefficient ◽  
Aircraft Design ◽  
Aerodynamic Characteristics ◽  
Viscous Drag ◽  
Layer Method ◽  
Boundary Layer Method ◽  
Dimensional Boundary ◽  
Classical Integral ◽  
Empirical Corrections

This paper will present the development of a simple subsonic boundary layer method suitable to be used coupled with panel methods in order to estimate the aerodynamic characteristics, including viscous drag and maximum lift coefficient, of 3D wings. The proposed method does not require viscous-inviscid iterations and is based on classical integral bi-dimensional boundary layer theory using Thwaites and Head ́s models with bi-dimensional empirical corrections applied to each wing strip being therefor robust and efficient to be used in the early conceptual stage of aircraft design. Presented results are compared to the Modified CS Method in an IBL scheme and experimental data and are shown to provide good results.

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