Volume 19, Issue 10 (October 2019)
Modares Mechanical Engineering 2019, 19(10): 2431-2441 |
Back to browse issues page
Download citation:
BibTeX | RIS | EndNote | Medlars | ProCite | Reference Manager | RefWorks
Send citation to:
BibTeX | RIS | EndNote | Medlars | ProCite | Reference Manager | RefWorks
Send citation to:
Sajadmanesh S M, Mojaddam M, Mohseni A. Investigating the Separation Bubble Behavior on the Suction Side of a High-Lift Low-Pressure Turbine Blade Using Proper Orthogonal Decomposition. Modares Mechanical Engineering 2019; 19 (10) :2431-2441
URL: http://mme.modares.ac.ir/article-15-26287-en.html
URL: http://mme.modares.ac.ir/article-15-26287-en.html
1- Energy Conversion Department, Faculty of Mechanical & Energy Engineering, Shahid Beheshti University (SBU), Tehran, Iran
2- Energy Conversion Department, Faculty of Mechanical & Energy Engineering, Shahid Beheshti University (SBU), Tehran, Iran , ar_mohseni@sbu.ac.ir
2- Energy Conversion Department, Faculty of Mechanical & Energy Engineering, Shahid Beheshti University (SBU), Tehran, Iran , ar_mohseni@sbu.ac.ir
Abstract: (3980 Views)
Turbofan engines are widely used in modern aircraft. Low-pressure turbines are the heaviest components of turbofan engines, and reduction of their weights is very effective in improving the specific fuel consumption and overall efficiency of these engines. One of the methods of decreasing the engine weight is to decrease the number of blades which is accompanied by an increase of the blade loading. For this purpose, high-lift airfoils can be used. As the occurrence of flow separation is very probable in high-lift blades, the recognition of the location and size of the separation bubble is important to assess the energy loss of flow. In this research, T106D-EIZ high-lift cascade is simulated by two-dimensional Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations with Shear Stress Transport (SST) turbulence model and γ-Re_θ transition model in two Reynolds numbers 200,000 and 60,000 at a constant isentropic exit Mach number of 0.4, which represent a typical flow condition in low-pressure turbine. The results show that when Reynolds number is high, the separation bubble remains small on the suction side and the separated shear layer returns to the blade surface, and the energy loss of flow decreases. On the other hand, at a low Reynolds number, the separation bubble grows and energy loss increases. Separation bubble is not directly detectable in an evaluation of pressure distribution. However, proper orthogonal decomposition of the pressure field provides the capability to identify flow structures including vortex stretching, the onset of flow separation, and flow reattachment. When the separation bubble is long, large vortical structures are formed on the suction surface. Release of these large vortices can increase the profile loss by more than 50 percent.
Keywords: Low-Pressure Turbine, High-Lift Blade, Separation Bubble, Separated Shear Layer, Proper Orthogonal Decomposition
Article Type: Original Research |
Subject:
Sonic Flow
Received: 2018/10/19 | Accepted: 2019/02/23 | Published: 2019/10/22
Received: 2018/10/19 | Accepted: 2019/02/23 | Published: 2019/10/22
References
1. Howell RJ, Ramesh ON, Hodson HP, Harvey NW, Schulte V. High lift and aft loaded profiles for low pressure turbines. ASME Proceedings Heat Transfer Electric Power Industrial and Cogeneration. 2000;3:V003T01A066. [Link] [DOI:10.1115/2000-GT-0261]
2. Zou Z, Wang S, Liu H, Zhang W. Flow mechanisms in low-pressure turbines. In: Zou Z, Wang S, Liu H, Zhang W. Axial turbine aerodynamics for aero-engines. Singapore: Springer; 2018. pp. 143-257. [Link] [DOI:10.1007/978-981-10-5750-2_4]
3. Hodson HP, Howell RJ. The role of transition in high-lift low-pressure turbines for aeroengines. Progress in Aerospace Sciences. 2005;41(6):419-454. [Link] [DOI:10.1016/j.paerosci.2005.08.001]
4. Curtis EM, Hodson HP, Banieghbal MR, Denton JD, Howell RJ, Harvey NW. Development of blade profiles for low-pressure turbine applications. Journal of Turbomachinery. 1997;119(3):531-538. [Link] [DOI:10.1115/1.2841154]
5. González P, Ulizar I, Vázquez R, Hodson HP. Pressure and suction surfaces redesign for high-lift low-pressure turbines. Journal of Turbomachinery. 2002;124(2):161-166. [Link] [DOI:10.1115/1.1452747]
6. Cardamone P, Stadtmüller P, Fottner L. Numerical investigation of the wake-boundary layer interaction on a highly loaded LP turbine cascade blade. ASME Proceedings Turbo Expo Parts A and B. 2002;5:401-409. [Link] [DOI:10.1115/GT2002-30367]
7. Bigoni F, Vagnoli S, Arts T, Verstraete T. Detailed numerical characterization of the suction side laminar separation bubble for a high-lift low pressure turbine blade by means of RANS and LES. ASME Proceedings Turbomachinery. 2016;2D:V02DT44A015. [Link] [DOI:10.1115/GT2016-56653]
8. Blaim FF, Brachmanski RE, Niehuis R. Investigation of variated unsteady inflow boundary conditions on the transition behavior of a low pressure turbine cascade family. ASME Proceedings Turbomachinery. 2014;2C:V02CT38A023. [Link] [DOI:10.1115/GT2014-25891]
9. Schobeiri MT, 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. ASME Proceedings Heat Transfer. 2014;5C:V05CT17A001. [Link] [DOI:10.1115/GT2014-25828]
10. Nikparto A, Schobeiri MT. Combined numerical and experimental investigations of heat transfer of a highly loaded low-pressure turbine blade under periodic inlet flow condition. Proceedings of the Institution of Mechanical Engineers Part A Journal of Power and Energy. 2018;232(7):769-784. [Link] [DOI:10.1177/0957650918758158]
11. Michelassi V, Chen LW, Pichler R, Sandberg RD. Compressible direct numerical simulation of low-pressure turbines-part II: Effect of inflow disturbances. Journal of Turbomachinery. 2015;137(7):071005. [Link] [DOI:10.1115/1.4029126]
12. Istvan MS, Yarusevych S. Effects of free-stream turbulence intensity on transition in a laminar separation bubble formed over an airfoil. Experiments in Fluids. 2018;59:52. [Link] [DOI:10.1007/s00348-018-2511-6]
13. Breuer M. Effect of inflow turbulence on an airfoil flow with laminar separation bubble: An LES study. Flow Turbulence and Combustion. 2018;101(2):433-456. [Link] [DOI:10.1007/s10494-017-9890-2]
14. Stadtmüller P, Fottner L. A test case for the numerical investigation of wake passing effects on a highly loaded LP turbine cascade blade. ASME Proceedings Aircraft Engine Marine Turbomachinery Microturbines and Small Turbomachinery. 2001;1:V001T03A015. [Link] [DOI:10.1115/2001-GT-0311]
15. Lengani D, Simoni D, Ubaldi M, Zunino P, Bertini F. Experimental investigation on the time-space evolution of a laminar separation bubble by POD and DMD. ASME Proceedings Turbomachinery. 2016;2B:V02BT38A049. [Link] [DOI:10.1115/GT2016-57581]
16. Mohammed-Taifour A, Weiss J. Unsteadiness in a large turbulent separation bubble. Journal of Fluid Mechanics. 2016;799:383-412. [Link] [DOI:10.1017/jfm.2016.377]
17. Haselbach F, Schiffer HP, Horsman M, Dressen S, Harvey N, Read S. The application of ultra high lift blading in the BR715 LP turbine. Journal of Turbomachinery. 2001;124(1):45-51. [Link] [DOI:10.1115/1.1415737]
18. Tropea C, Yarin A, Foss, JF, editors. Springer handbook of experimental fluid mechanics. Berlin/Heidelberg: Springer-Verlag; 2007. [Link] [DOI:10.1007/978-3-540-30299-5]
19. Coull JD, Thomas RL, Hodson HP. Velocity distributions for low pressure turbines. Journal of Turbomachinery. 2010;132(4):041006. [Link] [DOI:10.1115/1.3192149]
20. Menter FR, Langtry RB, Likki SR, Suzen YB, Huang PG, Völker S. A correlation-based transition model using local variables-part I: Model formulation. Journal of Turbomachinery. 2004;128(3):413-422. [Link] [DOI:10.1115/1.2184352]
21. Michelassi V, Wissink JG, Rodi W. Direct numerical simulation, large eddy simulation and unsteady Reynolds-averaged Navier-Stokes simulations of periodic unsteady flow in a low-pressure turbine cascade: A comparison. Proceedings of the Institution of Mechanical Engineers Part A Journal of Power and Energy. 2003;217(4):403-411. [Link] [DOI:10.1243/095765003322315469]
22. Lee D, Kawai S, Nonomura T, Anyoji M, Aono H, Oyama A, et al. Mechanisms of surface pressure distribution within a laminar separation bubble at different Reynolds numbers. Physics of Fluids. 2015;27(2):023602. [Link] [DOI:10.1063/1.4913500]
23. Zhang W, Zou Z, Qi L, Ye J, Wang L. Effects of freestream turbulence on separated boundary layer in a low-Re high-lift LP turbine blade. Computers & Fluids. 2015;109:1-12. [Link] [DOI:10.1016/j.compfluid.2014.12.014]
24. Marxen O, Henningson DS. The effect of small-amplitude convective disturbances on the size and bursting of a laminar separation bubble. Journal of Fluid Mechanics. 2011;671:1-33. [Link] [DOI:10.1017/S0022112010004957]
Send email to the article author
| Rights and permissions | |
 |
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. |