Experimental and computational heat transfer investigations are reported on the interior side of a nozzle guide vane (NGV) subjected to combined impingement and film cooling. The domain of study is a two-dimensional five-vane cascade having a space chord ratio of 0.88. The vane internal surface is cooled by dry air, supplied through the two impingement inserts: the front and the aft. The blowing ratio (ρcVcmVm) is varied systematically by varying the coolant mass flow through the impingement chamber and also by changing the mainstream Reynolds number, but by keeping a fixed spacing (H) to jet diameter (d) ratio of 1.2. The surface temperature distributions, at certain locations of the vane interior surface, are measured by pasting strips of liquid crystal sheets. The vane interior surface temperature distribution is also obtained by the computations carried out by using shear stress transport (SST) k–ω turbulence model in the flow solver ansys fluent-14. The computational data are in good agreement with the measured values of temperature. The internal heat transfer coefficients are thence determined from the computational data. The results show that, when the blowing ratio is increased by increasing the coolant flow rate, the average internal surface temperature decreases. However, when the blowing ratio is varied by increasing the mainstream Reynolds number, the internal surface temperature increases. Further, the temperature variations are different all along the internal surface from the leading edge to the trailing edge and are largely dependent on the coolant flow distributions on the internal as well as the external sides.

References

References
1.
Chupp
,
R.
,
Helms
,
H.
,
Mcfadden
,
P.
, and
Brown
,
T.
,
1969
, “
Evaluation of Internal Heat-Transfer Coefficients for Impingement Cooled Turbine Airfoils
,”
J. Aircr.
,
6
(
3
), pp.
203
208
.
2.
Bunker
,
R. S.
, and
Metzger
,
D. E.
,
1990
, “
Local Heat Transfer in Internally Cooled Turbine Airfoil Leading Edge Regions—Part I: Impingement Cooling Without Film Coolant Extraction
,”
ASME J. Turbomach.
,
112
(
3
), pp.
451
458
.
3.
Bunker
,
R. S.
, and
Metzger
,
D. E.
,
1990
, “
Local Heat Transfer in Internally Cooled Turbine Airfoil Leading Edge Regions—Part II: Impingement Cooling With Film Coolant Extraction
,”
ASME J. Turbomach.
,
112
(
3
), pp.
459
466
.
4.
Taslim
,
M. E.
, and
Khanicheh
,
A.
,
2006
, “
Experimental and Numerical Study on an Airfoil Leading Edge With and Without Showerhead and Gill Film Holes
,”
ASME J. Turbomach.
,
128
(
2
), pp.
310
320
.
5.
Jung
,
K.
, and
Hennecke
,
D. K.
,
2001
, “
Curvature Effects on Film Cooling With Injection Through Two Rows of Holes
,”
RTO AVT
Symposium on Heat Transfer and Cooling in Propulsion and Power Systems
, Loen, Norway, May 7–11.
6.
Ramakumar
,
B. V. N.
, and
Prasad
,
B. V. S. S. S.
,
2006
, “
Computational Investigation of Flow and Heat Transfer for a Row of Circular Jets Impinging on a Concave Surface
,”
ASME
Paper No. GT2006-90851.
7.
Cho
,
H. H.
, and
Goldstein
,
R. J.
,
1995
, “
Heat (Mass) Transfer and Film Cooling Effectiveness With Injection Through Discrete Holes—Part 1: Within Holes and on the Back Surface
,”
ASME J. Turbomach.
,
117
(
3
), pp.
440
450
.
8.
Cho
,
H. H.
, and
Rhee
,
D. H.
,
2001
, “
Local Heat/Mass Transfer Measurement on the Effusion Plate in Impingement/Effusion Cooling Systems
,”
ASME J. Turbomach.
,
123
(
3
), pp.
601
608
.
9.
Rhee
,
D. H.
,
Choi
,
J. H.
, and
Cho
,
H. H.
,
2003
, “
Flow and Heat (Mass) Transfer Characteristics in an Impingement/Effusion Cooling System With Cross Flow
,”
ASME J. Turbomach.
,
125
(
1
), pp.
74
82
.
10.
Ekkad
,
S. V.
,
Huang
,
Y.
, and
Han
,
J. C.
,
1999
, “
Impingement Heat Transfer on a Target Plate With Film cooling Holes
,”
AIAA J. Thermophys. Heat Transfer
,
13
(
4
), pp.
522
528
.
11.
Montomoli
,
F.
,
Massini
,
M.
,
Yang
,
H.
, and
Han
,
J. C.
,
2012
, “
The Benefit of High-Conductivity Materials in Film Cooled Turbine Nozzles
,”
Int. J. Heat Fluid Flow
,
34
, pp.
107
116
.
12.
Ravelli
,
S.
,
Dobrowolski
,
L.
, and
Bogard
,
D. G.
,
2010
, “
Evaluating the Effects of Internal Impingement Cooling on a Film Cooled Turbine Blade Leading Edge
,”
ASME
Paper No. GT2010-23002.
13.
Maikell
,
J.
,
Bogard
,
D. G.
,
Piggush
,
J.
, and
Kohli
,
A.
,
2011
, “
Experimental Simulation of a Film Cooled Turbine Blade Leading Edge Including Thermal Barrier Coating Effects
,”
ASME J. Turbomach.
,
133
(
1
), p.
011014
.
14.
Nathan
,
M. L.
,
Dyson
,
T. E.
,
Bogard
,
D. G.
, and
Bradshaw
,
S. D.
,
2013
, “
Adiabatic and Overall Effectiveness for the Showerhead Film Cooling of a Turbine Vane
,”
ASME J. Turbomach.
,
136
(
3
), p.
031005
.
15.
Ashok Kumar
,
M.
, and
Prasad
,
B. V. S. S. S.
,
2011
, “
Computational Investigations of Impingement Heat Transfer on an Effused Concave Surface
,”
Int. J. Fluid Mach. Syst.
,
5
(
2
), pp.
72
90
.
16.
Panda
,
R. K.
, and
Prasad
,
B. V. S. S. S.
,
2014
, “
Conjugate Heat Transfer From an Impingement and Film-Cooled Flat Plate
,”
J. Thermophys. Heat Transfer
,
28
(
4
), pp.
647
666
.
17.
Nirmalan
,
N. V.
,
Bunker
,
R. S.
, and
Hedlund
,
C. R.
,
2003
, “
The Measurement of Full-Surface Internal Heat Transfer Coefficients for Turbine Airfoils Using a Non-Destructive Thermal Inertia Technique
,”
ASME J. Turbomach.
,
125
(
1
), pp.
83
89
.
18.
Heidrich
,
P.
,
Wolfersdorf
,
J. V.
,
Schmidt
,
S.
, and
Schnieder
,
M.
,
2008
, “
Estimation of Internal Heat Transfer Coefficients and Detection of Rib Positions in Gas Turbine Blades From Transient Surface Temperature Measurements
,”
J. Phys. Conf. Ser.
,
135
, p.
012050
.
19.
Dees
,
J. E.
, and
Bogard
,
D. G.
,
2012
, “
Experimental Measurements and Computational Predictions for an Internally Cooled Simulated Turbine Vane
,”
ASME J. Turbomach.
,
134
(
6
), p.
061003
.
20.
Pujari
,
A. K.
,
Prasad
,
B. V. S. S. S.
, and
Sitaram
,
N.
,
2014
, “
Conjugate Heat Transfer Study at Interior Surface of NGV Leading Edge With Combined Shower Head and Impingement Cooling
,”
Int. J. Rotating Mach.
,
2014
, p.
754983
.
21.
Pujari
,
A. K.
,
2015
, “
Internal Heat Transfer Studies in a Gas Turbine Nozzle Guide Vane With Combined Impingement and Film Cooling
,” Ph.D. thesis, Department of Mechanical Engineering, Indian Institute of Technology, Chennai, India.
22.
Ansys
,
2011
, “
Ansys Fluent: 14.0 Theory Guide
,” ANSYS, Canonsburg, PA, pp.
218
221
.
23.
Celik
, I
. B.
,
Ghia
,
U.
,
Roache
,
P. J.
,
Freitas
,
C. J.
,
Coleman
,
H.
, and
Raad
,
P. E.
,
2008
, “
Procedure for Estimation and Reporting of Uncertainty Due to Discretization in CFD Applications
,”
ASME J. Fluids Eng.
,
130
(
7
), p.
07800
.
24.
Luo
,
J.
, and
Razinsky
,
E. H.
,
2007
, “
Conjugate Heat Transfer Analysis of a Cooled Turbine Vane Using the V2F Turbulence Model
,”
ASME J. Turbomach.
,
129
(
4
), pp.
773
781
.
25.
Chandran
,
P. M. D.
, and
Prasad
,
B. V. S. S. S.
,
2014
, “
A Heat Transfer Study on the Pressure and Suction Side of a Combined Film and Impingement Cooled NGV
,”
15th ISROMAC
, Paper No. WE101.
26.
Pujari
,
A. K.
,
Prasad
,
B. V. S. S. S.
, and
Sitaram
,
N.
,
2014
, “
An Internal Heat Transfer Study in a Cooled Nozzle Guide Vane of a Linear Cascade
,”
ASME
Paper No. GTINDIA 2014-8191.
27.
Pujari
,
A. K.
,
Prasad
,
B. V. S. S. S.
, and
Sitaram
,
N.
,
2015
, “
Heat Transfer Studies on the Interior Surfaces of Cooled Nozzle Guide Vane With Combined Impingement and Film Cooling Holes in a Linear Cascade
,”
ASME
Paper No. GT2015-43972.
28.
Katti
,
V.
, and
Prabhu
,
S.
,
2009
, “
Influence of Streamwise Pitch on the Local Heat Transfer Characteristics for In-Line Arrays of Circular Jets With Crossflow of Spent Air in One Direction
,”
Heat Mass Transfer
,
45
(
9
), pp.
1167
1184
.
You do not currently have access to this content.