Effect of non-axisymmetric contouring on performance and film cooling of a rotating turbine endwall subjected to the secondary air purge: A combined numerical and experimental study
Restricted accessResearch articleFirst published online December, 2015
Effect of non-axisymmetric contouring on performance and film cooling of a rotating turbine endwall subjected to the secondary air purge: A combined numerical and experimental study
Applying a new non-axisymmetric endwall contouring technology introduced by Turbomachinery Performance and Flow Research Laboratory (TPFL) at Texas A&M University to the second rotor row of a three-stage research turbine has shown that for a single rotor row a major turbine efficiency improvement can be achieved. Motivated by these results, numerical and experimental investigations were conducted to determine the effect of non-axisymmetric contouring on the endwall film cooling behavior of a rotating turbine row. To accomplish the film cooling, the endwall of the first rotor row is chosen for the contouring. It is subjected to the secondary air exiting from a large cavity through a circumferential slot that is inclined at 25° and impinges on the contoured hub. Performing Reynolds averaged Navier–Stokes (RANS) simulations by using the boundary conditions from the experiments, aerodynamics, performance, and film cooling effectiveness studies were performed by varying the injection blowing ratio and turbine rotational speed. Performance measurements were carried out within a rotational speed range of 1800–3000 r/min. The corresponding computational fluid dynamic simulations were carried out for four rotational speeds, 2000, 2400, 2600, and 3000 r/min. Comparison of the RANS aerodynamics simulations with experiments reveals noticeable differences. Considering the film cooling effectiveness, major differences between experiment and numerical results were observed and discussed in the paper.
Abdelfattah SA. Numerical and experimental analysis of multi-stage axial turbine performance at design and off-design conditions. Dissertation, Texas A&M University, 2013.
3.
Schobeiri MT, Gilarranz J and Johansen E. Final report on: efficiency, performance, and interstage flow field measurement of Siemens-Westinghouse HP-turbine blade series 9600 and 5600, Texas A&M University, University Publication, September 1999.
4.
Schobeiri MT, Gillaranz JL and Johansen ES. Aerodynamic and performance studies of a three stage high pressure research turbine with 3-D blades, design point and off-design experimental investigations. In: Proceedings of ASME Turbo Expo 2000, 2000-GT-0484, Munich, Germany, 8–11 May 2000.
5.
SchobeiriMTLuK. Endwall contouring using continuous diffusion: a new method and its application to a three-stage high pressure turbine. ASME J Turbomach2013; 136: 011006–011006.
6.
Hartland J and Gregory-Smith D. A design method for the profiling of end walls in turbines. ASME, GT-2002-30433. In: Proceedings of ASME turbo expo 2002, Amsterdam, The Netherlands, 3–6 June 2002.
7.
Ingram G, Gregory-Smith DG, Rose M, et al. The effect of end-wall profiling on secondary flow and loss development in a turbine cascade. In: Proceedings of ASME Turbo Expo 2002, 2002-GT-30339, Amsterdam, The Netherlands, 3–6 June 2002.
8.
Eymann S, Reinmöller U and Niehuis R. Improving 3D flow characteristics in a multistage LP turbine by means of endwall contouring and airfoil design modification - part 1: design and experimental investigation. In: Proceedings of IGTI’02 ASME turbo expo 2002, 2002-GT-30352, Amsterdam, The Netherlands, 3–6 June 2002.
9.
SauerHMuellerRVogelerK. Reduction of secondary flow losses in turbine cascades by leading edge modifications at the endwall. ASME J Turbomach2001; 123: 207–213.
10.
BrennanGHarveyNWRoseMG. Improving the efficiency of the trent 500-HP turbine using nonaxisymmetric end walls-part i: turbine design. ASME J Turbomach2003; 125: 497–504.
11.
Harvey NW, Rose MG, Brennan G, et al. Improving turbine efficiency using non-axisymmetric end walls: validation in the multi-row environment and with low aspect ratio blading. In: Proceedings of ASME turbo expo 2002, GT-2002-30337, Amsterdam, The Netherlands, 3–6 June 2002.
12.
Germain T, Nagel M, Raab I, et al. Improving efficiency of a high work turbine using non-axisymmetric end walls part i: endwall design and performance. In: Proceedings of ASME turbo expo 2008, GT2008-50469, Berlin, Germany, 9–13 June 2008.
13.
Snedden G, Dunn D, Ingram G, et al. The application of non-axisymmetric endwall contouring in a single stage, rotating turbine. In: Proceedings of ASME turbo expo 2009, GT2009-59169, Orlando, Florida USA, 8–12 June 2009.
14.
Snedden G, Dunn D, Ingram G, et al. The performance of a generic non-axisymmetric end wall in a single stage, rotating turbine at on and off-design conditions. In: Proceedings of ASME turbo expo 2010, GT2010-22006, Glasgow, UK, 14–18 June 2010.
15.
SuryanarayananAMhetrasSPSchobeiriMT. Film-cooling effectiveness on a rotating blade platform. J Turbomach2008; 131: 011014–011014.
16.
SuryanarayananAÖzturkBSchobeiriMT. Film-cooling effectiveness on a rotating turbine platform using pressure sensitive paint technique. J Turbomach2010; 132: 041001-1-12–041001-1-12.
17.
YangCSLinCLGauC. Film-cooling performance and heat transfer over an inclined film-cooled surface. J Thermophys Heat Transfer2008; 22: 485–492.
18.
Lin Y-L, Shih TI-P, Chyu MK, et al. Effects of gap leakage on fluid flow in a contoured turbine nozzle guide vane. ASME Paper, No. GT2000-0555, 2000.
19.
ThriftAATholeKAHadaS. Effects of an axisymmetric contoured endwall on a nozzle guide vane: adiabatic effectiveness measurements. J Turbomach2011; 133: 041007–1-10.
20.
SchuepbachPAbhariRSRoseMG. Influence of rim seal purge flow on the performance of an endwall-profiled axial turbine. ASME J Turbomach2011; 133: 021011–021011.
21.
JennyPAbhariRSRoseMG. A low pressure turbine with profiled endwalls and purge flow operating with a pressure side bubble. ASME J Turbomach2012; 134: 061038–061038.
22.
RezasoltaniMSchobeiriMTHanJC. Experimental investigation of the effect of purge flow on film cooling effectiveness on a rotating turbine with non-axisymmetric endwall contouring. ASME J Turbomach2013; 136: 091009–091009.
23.
Sharma K. Inter-stage and performance tests of a two-stage high-pressure turbine, Master’s Thesis, Texas A&M University, 2011.
24.
HolmanJP. Experimental methods for engineers, New York: McGraw Hill, 2000.
25.
Menter F. Zonal two equation k-ωturbulence models for aerodynamic flows. AIAA Paper 93-2906, 1993.
Abdelfattah SA and Schobeiri MT. Experimental and numerical investigations of aerodynamic behavior of a three-stage HP-turbine at different operating conditions. In: Proceedings of ASME turbo expo 2010, GT2010-23564, 14–18 June 2010, Glasgow, UK.
28.
Lu K, Schobeiri MT and Han JC. Numerical simulations of film cooling on rotating blade tips within a high-pressure turbine. In: Proceedings of ASME Turbo Expo 2013, GT2013-94806, 3–7 June 2013, San Antonio, Texas, USA.
29.
Schobeiri MT and Nikparto A. A comparative numerical study of aerodynamics and heat transfer on transitional flow around a highly loaded turbine blade with flow separation using RANS, URANS and LES. Journal of Engineering Applications of Computational Fluid Mechanics (submitted).
30.
Schobeiri MT. Applied fluid mechanics for engineers. McGraw Hill. ISBN: 9780071800044, New York, Chicago, San Franasisco, 2014.
31.
SchobeiriMTAbd-ElfattahSChibliH. A major paper “Investigating the Cause of Computational Fluid Dynamics Deficiencies in Accurately Predicting the Efficiency and Performance of High Pressure Turbines: A Combined Experimental and Numerical Study” ASME Transactions. J Fluids Eng2012; 134: 101104–1–101104-12.
32.
Schobeiri MT. On the reliability of RANS and URANS for simulating turbomachinery aerodynamic and heat transfer quantities, GT2013-95088, Invited Tutorial, 2013.
