Measurements in the Transition Region of a Turbine Blade Profile Under Compressible Conditions

2004 ◽  
Vol 127 (2) ◽  
pp. 400-403 ◽  
Author(s):  
E. J. Walsh ◽  
M. R. D. Davies
Keyword(s):  
Transition Region ◽  
Turbine Blade ◽  
Blade Profile

A wind turbine blade profile analysis code based on the singularities method

2005 ◽  
Vol 30 (3) ◽  
pp. 339-352 ◽  
Author(s):  
Badreddine Kamoun ◽  
David Afungchui ◽  
Alain Chauvin
Keyword(s):  
Wind Turbine ◽  
Turbine Blade ◽  
Profile Analysis ◽  
Wind Turbine Blade ◽  
Blade Profile

Choice of the Pseudo-Optimal Configuration of a Cooled Gas-Turbine Blade Based on a Constrained Minimization of the Global Entropy Production Rate

1996 ◽  
Author(s):  
Gianni Natalini ◽  
Enrico Sciubba
Keyword(s):  
Gas Turbine ◽  
Turbine Blade ◽  
Entropy Generation ◽  
Optimization Procedure ◽  
Optimal Configuration ◽  
Generation Rate ◽  
Maximum Temperature ◽  
Entropy Generation Rate ◽  
Gas Turbine Blade ◽  
Blade Profile

The problem of determining the optimal configuration of a cooled gas-turbine blade is approached by an entropy minimization technique proposed in previous works by the same authors. The present paper describes the application of the same line of thought to a more complex (and realistic) pseudo-optimization procedure, in which the objective function is again the global entropy generation rate, but two integral constraints are added to the original formulation: the maximum blade temperature (weak constraint) and the overall enthalpy drop of the working fluid in the blade passage (strong constraint). The discontinuous optimization procedure is presented here in an application which resembles a trial-and-error technique, but can be rigorously and formally described and implemented [12]. As a “zero configuration”, a realistic 2-D geometry is considered, and the thermo-fluiddynamic field around it is computed via a standard finite-element code. Then, the entropy generation rates in the blade/fluid system are calculated, and the value of the overall enthalpy drop of the gas as well as the value and location of the maximum blade temperature are recorded. Keeping all other parameters fixed (in particular, maintaining the same cooling air flowrate), the geometry of the blade is slightly “perturbed”, by introducing arbitrary modifications in the blade profile, the number and location of cooling holes, etc. Again, the velocity and temperature fields are computed, and inlet conditions are tuned so that the overall enthalpy drop remains approximately constant and the blade maximum temperature does not exceed a certain assigned value. An “optimal” configuration is found, which is affected by the minimal entropy generation rate, while abiding to the imposed constraints. The procedure is demonstrated on a realistic blade profile, and is shown to produce a better performing cascade, at least in this 2-D simulation. The extension to 3-D problems is — in principle — straightforward (but see Section 3 for further comments).

scholarly journals Study of ice accretion on wind turbine blade profiles using thermal infrared imaging

2020 ◽  
pp. 0309524X2093394
Author(s):  
Adeel Yousuf ◽  
Jia Yi Jin ◽  
Pavlo Sokolov ◽  
Muhammad S Virk
Keyword(s):  
Temperature Distribution ◽  
Surface Temperature ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Infrared Imaging ◽  
Thermal Infrared ◽  
Ice Accretion ◽  
Blade Profile ◽  
Thermal Infrared Imaging ◽  
Surface Temperature Distribution

Atmospheric icing has been recognized as hindrance in proper utilization of good wind resources in cold regions. There is a growing need to better understand the ice accretion physics along wind turbine blades to improve its performance and for optimal design of anti/de-icing system. This article describes a study of ice accretion along wind turbine blade profiles using thermal infrared imaging. Surface temperature distribution along four different blade profile surfaces is studied at different operating conditions. Analysis shows that surface temperature distribution along blade profile surface during ice accretion process is a dynamic process and change in atmospheric conditions and blade geometric characteristics significantly affects the surface temperature and resultant ice accretion. The effect of blade geometry on ice accretion is more prominent in case of wet ice conditions due to low freezing fraction and water run back along blade profile surface.

Comparison of Two Unsteady Intermittency Models for Bypass Transition Prediction on a Turbine Blade Profile

2008 ◽  
Vol 81 (3) ◽  
pp. 369-394 ◽  
Author(s):  
Władysław Piotrowski ◽  
Koen Lodefier ◽  
Slawomir Kubacki ◽  
Witold Elsner ◽  
Erik Dick
Keyword(s):  
Turbine Blade ◽  
Bypass Transition ◽  
Blade Profile ◽  
Transition Prediction

Three-Dimensional Aerodynamic Design Optimization of a Turbine Blade by Using an Adjoint Method

2009 ◽  
Author(s):  
Jiaqi Luo ◽  
Juntao Xiong ◽  
Feng Liu ◽  
Ivan McBean
Keyword(s):  
Design Optimization ◽  
Turbine Blade ◽  
Adjoint Method ◽  
Euler Method ◽  
Adjoint Equations ◽  
Design Parameters ◽  
Aerodynamic Design ◽  
Blade Profile ◽  
Profile Shape ◽  
Aerodynamic Design Optimization

This paper presents the application of an adjoint method to the aerodynamic design optimization of a turbine blade. With the adjoint method, the complete gradient information needed for optimization can be obtained by solving the governing flow equations and their corresponding adjoint equations only once, regardless of the number of design parameters. The formulations including imposition of appropriate boundary conditions for the adjoint equations of the Euler equations for turbomachinery problems are presented. Two design cases are demonstrated for a turbine cascade that involves a high tip flare, characteristic of steam turbine blading in low pressure turbines. The results demonstrate that the design optimization method is effective and the redesigned blade yielded weaker shock and compression waves in the supersonic region of the flow while satisfying the specified constraint. The relative effects of changing blade profile stagger, modifying the blade profile shape, and changing both stagger and profile shape at the same time are examined and compared. Navier-Stokes calculations are performed to confirm the performance at both the design and off-design conditions of the designed blade profile by the Euler method.

A Low Reynolds Number Experimental Evaluation of Tubercles on a Low-Pressure Turbine Cascade

2019 ◽  
Author(s):  
Stephen A. Pym ◽  
Asad Asghar ◽  
William D. E. Allan ◽  
John P. Clark
Keyword(s):  
Boundary Layer ◽  
Turbine Blade ◽  
Reynolds Numbers ◽  
Low Pressure ◽  
Blade Profile ◽  
Suction Surface ◽  
Low Reynolds Numbers ◽  
Low Pressure Turbine ◽  
Low Reynolds ◽  
Highly Loaded

Abstract Aircraft are operating at increasingly high-altitudes, where decreased air density and engine power settings have led to increasingly low Reynolds numbers in the low-pressure turbine portion of modern-day aeroengines. These operating conditions, in parallel with highly-loaded blade profiles, result in non-reattaching laminar boundary layer separation along the blade suction surface, increasing loss and decreasing engine performance. This work presents an experimental investigation into the potential for integrated leading-edge tubercles to improve blade performance in this operating regime. A turn-table cascade test-section was constructed and commissioned to test a purpose-designed, forward-loaded, low-pressure turbine blade profile at various incidences and Reynolds numbers. Baseline and tubercled blades were tested at axial chord Reynolds numbers at and between 15 000 and 60 000, and angles of incidence ranging from −5° to +10°. Experimental data collection included blade surface pressure measurements, total pressure loss in the blade wakes, hot-wire anemometry, surface hot-film measurements, and surface flow visualization using tufts. Test results showed that the implementation of tubercles did not lead to a performance enhancement. However, useful conclusions were drawn regarding the ability of tubercles to generate stream-wise vortices at ultra-low Reynolds numbers. Additional observations helped to characterize the suction surface boundary layer over the highly-loaded, low-pressure turbine blade profile when at off-design conditions. Recommendations were made for future work.

Sign in / Sign up

Export Citation Format

Share Document