DocumentCode :
2087744
Title :
Investigation of thickness effects on 2D NACA symmetric foils
Author :
Sarraf, C. ; Jaouen, R. ; Djeridi, H. ; Billard, J.Y.
Author_Institution :
Res. Inst. of French Naval Acad., Ecole Navale, Brest Armees, France
Volume :
2
fYear :
2005
fDate :
20-23 June 2005
Firstpage :
1298
Abstract :
A numerical and experimental study on the hydrodynamic behaviour of 2D NACA (15, 25, 35%) symmetric hydrofoils at high chord (/spl ap/10/sup 6/) Reynolds numbers and high angles of attack is performed. The focus is devoted to the comparison between results particularly for stall conditions corresponding to unsteady separated flow. The effect of thickness on the hydrodynamic coefficients and the topology of the flow are studied and the capacity of commercial code to predict the hydrofoil stall by Reynolds-Averaged Navier Stokes equations is analysed. The hydrodynamic coefficients are measured using a force balance and the flow patterns are investigated using LDV techniques. The cavitating incipient flow has been investigated to determine the minimum pressure coefficient and correlations are proposed to join these results to the thickness effect. All the calculations (steady and unsteady) have been performed using FLUENT/spl reg/ code. The emphasis is on turbulence modelling, grid size and boundary layer conditions on the foil. The computation is validated with very detailed experimental data. A hysteretic behaviour of force coefficient is highlighted and the development of leading edge vortices before and after stall occurrence is characterised.
Keywords :
Navier-Stokes equations; cavitation; flow separation; geophysical fluid dynamics; hydrodynamics; marine vehicles; oceanographic equipment; turbulence; vortices; 2D NACA symmetric foils; FLUENT code; Navier Stokes equations; Reynolds number; angle of attack; boundary layer conditions; cavitating incipient flow; edge vortices; flow patterns; flow topology; force balance; force coefficient hysteretic behaviour; grid size; hydrodynamic coefficients; hydrodynamics; hydrofoil; stall conditions; thickness effects; turbulence modelling; unsteady separated flow; Fluid flow measurement; Force measurement; Hydrodynamics; Hysteresis; Jacobian matrices; Marine vehicles; Navier-Stokes equations; Testing; Topology; Velocity measurement;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Oceans 2005 - Europe
Conference_Location :
Brest, France
Print_ISBN :
0-7803-9103-9
Type :
conf
DOI :
10.1109/OCEANSE.2005.1513247
Filename :
1513247
Link To Document :
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