This paper presents the findings of an experimental and numerical investigation on the shock effect on heat transfer coefficient and film-cooling effectiveness. In this study, coolant was injected on the blade surface through a fan-shaped hole in a transonic cascade. The experimental results indicate that on the film-cooled suction surface of the blade, the shock from the adjacent blade impinging on the suction surface causes the film-cooling effectiveness to drop quickly by 18%, and then stay at a low level downstream of the shock. The shock also causes the local heat transfer coefficient to decrease rapidly by 25%, but then rise back up immediately after the shock. The results from the numerical study supported the film-cooling effectiveness and heat transfer coefficient trends that were observed in the experiment. A detailed analysis of the numerical results reveals that the rapid change of the film-cooling effectiveness is due to the near surface secondary flows, which push the hot mainstream air toward the injection centerline and lifts the low temperature core away from the surface. This secondary flow is a result of a spanwise pressure gradient. The drop in heat transfer coefficient is caused by a boundary layer separation bubble which results from an adverse streamwise pressure gradient at the shock position.

References

References
1.
Popp
,
O.
,
Smith
,
D. E.
,
Bubb
,
J. V.
,
Grabowski
,
H. C.
,
Diller
,
T. E.
,
Schetz
,
J. A.
, and
Ng
,
W. F.
,
2000
, “
An Investigation of Heat Transfer in a Film Cooled Transonic Turbine Cascade, Part II: Unsteady Heat Transfer
,”
ASME
Paper No. GT-2000-203.
2.
Ligrani
,
P. M.
,
Saumweber
,
C.
,
Schulz
,
A.
, and
Wittig
,
S.
,
2001
, “
Shock Wave-Film Cooling Interactions in Transonic Flows
,”
ASME J. Turbomach.
,
123
(
4
), pp.
788
797
.
3.
Zhang
,
C. X.-Z.
, and
Hassan
,
I.
,
2009
, “
Computational Study of the Effects of Shock Waves on Film Cooling Effectiveness
,”
ASME J. Eng. Gas Turbines Power
,
131
(
3
), p.
031901
.
4.
Göttlich
,
E.
,
Lang
,
H.
,
Sanz
,
W.
, and
Woisetschläger
,
J.
,
2002
, “
Experimental Investigation of an Innovative Cooling System (ICS) for High Temperature Transonic Turbine Stages
,”
ASME
Paper No. GT-2002-30341.
5.
Ochs
,
M.
,
Schulz
,
A.
, and
Bauer
,
H.-J.
,
2007
, “
Investigation of The Influence of Trailing Edge Shock Waves on Film Cooling Performance of Gas Turbine Airfoils
,”
ASME
Paper No. GT-2007-27482.
6.
Carnevale
,
M.
,
D'Ammaro
,
A.
,
Montomoli
,
F.
, and
Salvadori
,
S.
,
2014
, “
Film Cooling and Shock Interaction: An Uncertainty Quantification Analysis With Transonic Flows
,”
ASME
Paper No. GT2014-25024.
7.
Xue
,
S.
,
Ng
,
W.
,
Zhang
,
L.
, and
Moon
,
H.
,
2012
, “
Fan-Shaped Hole Film Cooling on Turbine Blade in a Transonic Cascade With High Freestream Turbulence
,”
50th AIAA Aerospace Sciences Meeting
, Nashville, TN,
AIAA
Paper No. AIAA-2012-0368.
8.
Xue
,
S.
,
Roy
,
A.
,
Ng
,
W. F.
, and
Ekkad
,
S. V.
,
2014
, “
A Novel Transient Technique to Determine Recovery Temperature, Heat Transfer Coefficient, and Film Cooling Effectiveness Simultaneously in a Transonic Turbine Cascade
,”
ASME J. Therm. Sci. Eng. Appl.
,
7
(
1
), p.
011016
.
9.
Wu
,
H.
,
Nasir
,
S.
,
Ng
,
W. F.
, and
Moon
,
H. K.
,
2008
, “
Showerhead Film Cooling Performance of a Transonic Turbine Vane at High Freestream Turbulence (Tu = 16%): 3-D CFD and Comparison with Experiment
,”
ASME
Paper No. IMECE2008-67782.
10.
Xue
,
S.
,
2012
, “
Fan-Shaped Hole Film Cooling on Turbine Blade and Vane in a Transonic Cascade With High Freestream Turbulence
,” Ph.D. thesis, Virginia Polytechnic Institute and State University, Blacksburg, VA.
11.
Carullo
,
J. S.
,
Nasir
,
S.
,
Cress
,
R. D.
,
Ng
,
W. F.
,
Thole
,
K.
,
Zhang
,
L.
, and
Moon
,
H.
,
2010
, “
The Effects of Freestream Turbulence, Turbulence Length Scale, and Exit Reynolds Number on Turbine Blade Heat Transfer in a Transonic Cascade
,”
ASME J. Turbomach.
,
133
(
1
), p.
011030
.
12.
Berhe
,
M. K.
, and
Patankar
,
S. V.
,
1999
, “
Curvature Effects on Discrete Hole Film Cooling
,”
ASME J. Turbomach.
,
121
(
4
), pp.
781
791
.
13.
Berhe
,
M. K.
, and
Patankar
,
S. V.
,
1999
, “
Investigation of Discrete-Hole Film Cooling Parameters Using Curved-Plate Models
,”
ASME J. Turbomach.
,
121
(
4
), pp.
792
803
.
14.
de la Loma
,
A.
,
Paniagua
,
G.
,
Verrastro
,
D.
, and
Adami
,
P.
,
2008
, “
Transonic Turbine Stage Heat Transfer Investigation in Presence of Strong Shocks
,”
ASME J. Turbomach.
,
130
(
3
), p.
031019
.
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