The results of this investigation come from two linear cascades at high diffusion factors (DFs). The measurements presented for each low-pressure turbine (LPT) profile were conducted at midspan under a range of Reynolds- and exit Mach numbers. The exit Mach number was varied in a range covering low subsonic up to values where a transonic flow regime on the suction side of the blade could be expected. This work focuses on two profiles with a diffusion factor in a range of , where values in this range are considered as a comparable for the two cascades. Profile A is a front-loaded design and has shown no obvious flow separation on the suction side of the blade. Compared to the design A, design B is a more aft-loaded profile which exhibits flow separation on the suction side for all Reynolds numbers investigated. The integral total pressure losses were evaluated by wake traverses downstream of the airfoil. To determine the isentropic Mach numbers and the character of the boundary layer along the suction side of the profile, the static pressure measurements and traverses with a flattened Pitot probe were carried out. A correlation between the position of maximum Mach number on the suction side and the integral total pressure losses has been successfully established. The results show that the optimum location of peak Mach number to minimize integral total pressure losses is significantly dependent on the Reynolds number. However, the correlation presented in this paper, which is based on the data of the integral total pressure losses of an attached boundary layer, is not able to predict the integral total pressure loss or the location of the maximum Mach number on the suction side of the blade when an open separation bubble occurs.
Skip Nav Destination
Article navigation
October 2017
Research-Article
Mach Number Distribution and Profile Losses for Low-Pressure Turbine Profiles With High Diffusion Factors
Roland Brachmanski,
Roland Brachmanski
Institute of Jet Propulsion,
Universität der Bundeswehr München,
Neubiberg 85577, Germany
e-mail: roland.brachmanski@unibw.de
Universität der Bundeswehr München,
Neubiberg 85577, Germany
e-mail: roland.brachmanski@unibw.de
Search for other works by this author on:
Reinhard Niehuis
Reinhard Niehuis
Institute of Jet Propulsion,
Universität der Bundeswehr München,
Neubiberg 85577, Germany
e-mail: reinhard.niehuis@unibw.de
Universität der Bundeswehr München,
Neubiberg 85577, Germany
e-mail: reinhard.niehuis@unibw.de
Search for other works by this author on:
Roland Brachmanski
Institute of Jet Propulsion,
Universität der Bundeswehr München,
Neubiberg 85577, Germany
e-mail: roland.brachmanski@unibw.de
Universität der Bundeswehr München,
Neubiberg 85577, Germany
e-mail: roland.brachmanski@unibw.de
Reinhard Niehuis
Institute of Jet Propulsion,
Universität der Bundeswehr München,
Neubiberg 85577, Germany
e-mail: reinhard.niehuis@unibw.de
Universität der Bundeswehr München,
Neubiberg 85577, Germany
e-mail: reinhard.niehuis@unibw.de
1Corresponding author.
Contributed by the International Gas Turbine Institute (IGTI) of ASME for publication in the JOURNAL OF TURBOMACHINERY. Manuscript received August 7, 2016; final manuscript received March 5, 2017; published online May 9, 2017. Assoc. Editor: Guillermo Paniagua.
J. Turbomach. Oct 2017, 139(10): 101002 (10 pages)
Published Online: May 9, 2017
Article history
Received:
August 7, 2016
Revised:
March 5, 2017
Citation
Brachmanski, R., and Niehuis, R. (May 9, 2017). "Mach Number Distribution and Profile Losses for Low-Pressure Turbine Profiles With High Diffusion Factors." ASME. J. Turbomach. October 2017; 139(10): 101002. https://doi.org/10.1115/1.4036436
Download citation file:
Get Email Alerts
Cited By
Related Articles
Effect of Roughness and Unsteadiness on the Performance of a New Low Pressure Turbine Blade at Low Reynolds Numbers
J. Turbomach (July,2010)
Hot-Film Measurements on a Low Pressure Turbine Linear Cascade With Bypass Transition
J. Turbomach (September,2015)
On the Physics of Flow Separation Along a Low Pressure Turbine Blade Under Unsteady Flow Conditions
J. Fluids Eng (May,2005)
A Study of Advanced High-Loaded Transonic Turbine Airfoils
J. Turbomach (October,2006)
Related Proceedings Papers
Related Chapters
Introduction
Design and Analysis of Centrifugal Compressors
Aerodynamic Performance Analysis
Axial-Flow Compressors
Cavitating Structures at Inception in Turbulent Shear Flow
Proceedings of the 10th International Symposium on Cavitation (CAV2018)