Skin friction coefficients and heat transfer coefficients are measured for a range of regular and random roughnesses on the suction side of a simulated gas turbine vane. The skin friction coefficients are calculated using boundary layer data and the momentum integral method. High resolution surface temperature data measured with an IR camera yield local heat transfer values. 80 grit, 50 grit, 36 grit, and 20 grit sandpapers along with a regular array of conical roughness elements are tested. Measured skin friction coefficient data show that the conical roughness array behaves very similar to the 50 grit, 36 grit, and 20 grit sandpapers in terms of the effect of the roughness on the hydrodynamic boundary layer. In terms of heat transfer, the conical roughness array is most similar to the 80 grit sandpaper, which are both lower than the roughest sandpapers tested. These data show that the particular regular array of roughness elements tested has fundamentally different behavior than randomly rough surfaces for this position on the simulated turbine vane. In addition, this difference is in the opposite direction as seen in previous experimental studies. In order to draw a more general conclusion about the nature of random and regular roughness, a parametric study of regular roughness arrays should be performed.

1.
Bogard
,
D. G.
,
Schmidt
,
D. L.
, and
Tabbita
,
M.
, 1998, “
Characterization and Laboratory Simulation of Turbine Airfoil Surface Roughness and Associated Heat Transfer
,”
ASME J. Turbomach.
0889-504X,
120
, pp.
337
342
.
2.
Nikuradse
,
J.
, 1933, “
Stromungsgesetze in Rauchen Rohren
,”
Forschungsheft
361, Vol. B,
VDI Verlag
,
Berlin
.
3.
Kithcart
,
M. E.
, and
Klett
,
D. E.
, 1996, “
Heat Transfer and Skin Friction Comparison of Dimpled Versus Protrusion Roughness
,”
J. Enhanced Heat Transfer
1065-5131,
3
(
4
), pp.
273
280
.
4.
Stripf
,
M.
,
Schulz
,
A.
, and
Wittig
,
S.
, 2005, “
Surface Roughness Effects on External Heat Transfer of a HP Turbine Vane
,”
ASME J. Turbomach.
0889-504X,
127
, pp.
200
208
.
5.
Bons
,
J. P.
,
Taylor
,
R. P.
,
McClain
,
S. T.
, and
Rivir
,
R. B.
, 2001, “
The Many Faces of Turbine Surface Roughness
,” ASME Paper No. 2001-GT-0163.
6.
Bons
,
J. P.
, 2002, “
St and cf Augmentation for Real Turbine Roughness With Elevated Freestream Turbulence
,” ASME Paper No. GT-2002–30198.
7.
Belnap
,
B. J.
,
van Rij
,
J. A.
, and
Ligrani
,
P. M.
, 2002, “
A Reynolds Analogy for Real Component Surface Roughness
,”
Int. J. Heat Mass Transfer
0017-9310,
45
, pp.
3089
3099
.
8.
Rutledge
,
J. L.
,
Robertson
,
D. R.
, and
Bogard
,
D. G.
, 2005, “
Degradation of Film Cooling Performance on a Turbine Vane Suction Side Due to Surface Roughness
,” ASME Paper No. GT2005-69045.
9.
Bogard
,
D. G.
,
Snook
,
D.
, and
Kohli
,
A.
, 2003, “
Rough Surface Effects on Film Cooling of the Suction Side Surface of a Turbine Vane
,” ASME Paper No. IMECE2003-42061.
10.
Sigal
,
A.
, and
Danberg
,
J. E.
, 1990, “
New Correlation of Roughness Density Effect on the Turbulent Boundary Layer
,”
AIAA J.
0001-1452,
28
(
3
), pp.
554
556
.
11.
Keller
,
F. J.
, and
Wang
,
T.
, 1993, “
Flow and Thermal Structures in Heated Transitional Boundary Layers With and Without Streamwise Acceleration
,” Final Report, Clemson University.
12.
Stripf
,
M.
,
Schulz
,
A.
, and
Bauer
,
H.-J.
, 2006, “
Modeling of Rough Wall Boundary Layer Transition and Heat Transfer on Turbine Airfoils
,” ASME Paper No. GT2006-90316.
13.
White
,
F. M.
, 1991,
Viscous Fluid Flow
,
2nd ed.
,
McGraw-Hill
,
New York
.
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