A laboratory experimental method and an analysis technique are presented for evaluation of individual film-cooling row flow capacity characteristics. The method is particularly suited to complex systems such as hot section nozzle guide vanes (NGV) with lossy feed system characteristics. The method is believed to be both more accurate and more experimentally efficient than previous techniques. The new analysis technique uses an experimentally calibrated network model to represent the complex feed system and replaces the need for internal loss measurements, which are both demanding and inaccurate. Experiments are performed in the purpose-built University of Oxford Coolant Capacity Rig (CCR), a bench-top, blow-down type facility with atmospheric back-pressure. The design of the CCR is informed by the requirements to assess engine-scale film-cooled components rapidly, accurately, and precisely. Improvements in the experimental method include a differential mass flow rate measurement method (which eliminates the effect of leaks and minimizes the number of rows that must be blanked, ensuring that the internal coupling is as close as possible to the engine condition) and a variable bypass flow which ensures the mass flow measurement nozzle always operates within its calibrated range. We demonstrate the method using two high-pressure (HP) NGV designs: an engine part with relatively uncoupled (in terms of internal loss) cooling rows; and a laser-sintered part with highly coupled cooling rows. We show that the individual-row flow capacity of a high-pressure nozzle guide vane (HPNGV) can be evaluated in the CCR in a single day to a 2σ precision of approximately 0.5% and a 2σ accuracy (bias) of 0.6%. The importance of performing individual-row capacity measurements is demonstrated: failure to scale flow capacity on a row-by-row basis introduces an error of 30% in the engine situation.

References

1.
Povey
,
T.
,
2010
, “
Effect of Film Cooling on Turbine Capacity
,”
ASME J. Eng. Gas Turbines Power
,
132
(
1
), p.
011901
.
2.
Horlock
,
J. H.
,
Watson
,
D. T.
, and
Jones
,
T. V.
,
2001
, “
Limitations on Gas Turbine Performance Imposed by Large Turbine Cooling Flows
,”
ASME J. Eng. Gas Turbines Power
,
123
(
3
), pp.
487
494
.
3.
Kirollos
,
B.
, and
Povey
,
T.
,
2017
, “
Laboratory Infrared Thermal Assessment of Laser-Sintered High-Pressure Nozzle Guide Vanes to Derisk Engine Design Programs
,”
ASME J. Turbomach.
,
139
(
4
), p.
041009
.
4.
Drost
,
U.
, and
Bölcs
,
A.
,
1999
, “
Performance of a Turbine Airfoil With Multiple Film Cooling Stations—Part II: Aerodynamic Losses
,”
ASME
Paper No. 99-GT-042.
5.
Rowbury
,
D. A.
,
Oldfield
,
M. L. G.
,
Lock
,
G. D.
, and
Dancer
,
S. N.
,
1998
, “
Scaling of Film Cooling Discharge Coefficient Measurement to Engine Conditions
,”
ASME
Paper No. 98-GT-079.
6.
Rowbury
,
D.
,
1998
, “
Discharge Coefficients of Nozzle Guide Vane Film Cooling Holes
,” Ph.D. thesis, University of Oxford, Oxford, UK.
7.
BSI
,
2005
, “
Measurement of Gas Flow by Means of Critical Flow Venturi Nozzles
,” BSI, London, Standard No.
BS EN ISO 9300:2005
.https://www.scribd.com/document/252123388/Measurement-of-Gas-Flow-by-Means-of-Critical-Flow-Venturi-Nozzles
8.
Povey
,
T.
,
Sharpe
,
M.
, and
Rawlinson
,
A. J.
,
2011
, “
Experimental Measurements of Gas Turbine Flow Capacity Using a Novel Transient Technique
,”
ASME J. Turbomach.
,
133
(
1
), p.
011005
.
9.
Luque
,
S.
,
Batstone
,
J.
,
Gillespie
,
D. R. H.
,
Povey
,
T.
, and
Romero
,
E.
,
2014
, “
Full Thermal Experimental Assessment of a Dendritic Turbine Vane Cooling Scheme
,”
ASME J. Turbomach.
,
136
(
2
), p.
021011
.
10.
Luque
,
S.
, and
Povey
,
T.
,
2011
, “
A Novel Technique for Assessing Turbine Cooling System Performance
,”
ASME J. Turbomach.
,
133
(
3
), p.
031013
.
11.
Luque
,
S.
,
Aubry
,
J.
, and
Povey
,
T.
,
2009
, “
A New Engine-Parts Annular Sector Cascade to Prove NGV Cooling Systems
,”
Eighth European Conference on Turbomachinery, Fluid Dynamics and Thermodynamics
, Graz, Austria, Mar. 23–27, pp.
865
878
.
12.
Luque Martinez
,
S. G.
,
2011
, “
A Fully-Integrated Approach to Gas Turbine Cooling System Research
,” Ph.D thesis, University of Oxford, Oxford, UK.
13.
Kirollos
,
B.
, and
Povey
,
T.
,
2014
, “
Reverse-Pass Cooling Systems for Improved Performance
,”
ASME J. Turbomach.
,
136
(
11
), p.
111004
.
14.
Han
,
J. C.
, and
Zhang
,
Y. M.
,
1992
, “
High Performance Heat Transfer Ducts With Parallel Broken and V-Shaped Broken Ribs
,”
Int. J. Heat Mass Transfer
,
35
(
2
), pp.
513
523
.
15.
Park
,
J. S.
,
Han
,
J. C.
,
Huang
,
Y.
,
Ou
,
S.
, and
Boyle
,
R. J.
,
1992
, “
Heat Transfer Performance Comparisons of Five Different Rectangular Channels With Parallel Angled Ribs
,”
Int. J. Heat Mass Transfer
,
35
(
11
), pp.
2891
2903
.
You do not currently have access to this content.