scholarly journals Study of low Reynolds number effects on the losses in low-pressure turbine blade rows

1998 ◽  
Author(s):  
Daniel Dorney ◽  
David Ashpis
Keyword(s):  
Reynolds Number ◽  
Turbine Blade ◽  
Low Reynolds Number ◽  
Low Pressure ◽  
Low Pressure Turbine ◽  
Reynolds Number Effects ◽  
Low Reynolds

The Influence of Mach Number on the Boundary Layer Development of High-Lift Low Pressure Turbine in Low Reynolds Number

2020 ◽  
Author(s):  
Wenhua Duan ◽  
Jian Liu ◽  
Weiyang Qiao
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Mach Number ◽  
Turbine Blade ◽  
Low Reynolds Number ◽  
Low Pressure ◽  
High Lift ◽  
Low Pressure Turbine ◽  
Boundary Layer Development ◽  
Layer Development

Abstract A numerical analysis of the effect of Mach number on the boundary layer development and aerodynamic performance of a high-lift, after loaded low pressure turbine blade is presented in this paper. The turbine blade is designed for the GTF engine and works in a low Reynolds number, high Mach number environment. Three different isentropic exit Mach numbers (0.14, 0.87 and 1.17) are simulated by large eddy simulation method, while the Reynolds number based on the axial chord length of the blade and the exit flow velocity is kept the same (1 × 105). The condition Mais,2 = 0.14 represents the lowspeeed wind tunnel environment which is usually used in the low pressure turbine investigation. The condition Mais,2 = 0.87 represents the design point of the turbine blade. The condition Mais,2 = 1.17 represents the severe environment when the shock wave shows up. A comparison of the boundary layer development is made and the total pressure loss results from the boundary layer is discussed.

A CFD and Experimental Investigation of Unsteady Wake Effects on a Highly Loaded Low Pressure Turbine Blade at Low Reynolds Number

2010 ◽  
Author(s):  
Darius D. Sanders ◽  
Chase A. Nessler ◽  
Rolf Sondergaard ◽  
Marc D. Polanka ◽  
Christopher Marks ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Turbine Blade ◽  
Flow Model ◽  
Low Pressure ◽  
Transitional Flow ◽  
Blade Design ◽  
Low Pressure Turbine ◽  
Low Reynolds ◽  
Turbine Blade Design ◽  
Lp Turbine

The flowfield of the L1A low pressure (LP) turbine blade subjected to traversing upstream wakes was experimentally and computationally investigated at an inlet Reynolds number of 25,000. The L1A profile is a high-lift aft-loaded low pressure turbine blade design. The profile was designed to separate at low Reynolds numbers making it an ideal airfoil for use in flow separation control studies. This study applied a new two-dimensional CFD model to the L1A LP turbine blade design using a three-equation eddy-viscosity type transitional flow model developed by Walters and Leylek. Velocity field measurements were obtained by two-dimensional planer particle image velocimetry, and comparisons were made to the CFD predictions using the Walters and Leylek [13] k-kL-ω transitional flow model and the Menter’s [24] k-ω(SST) model. Hotwire measurements and pressure coefficient distributions were also used to compare each model’s ability to predict the wake produced from the wake generator, and the loading on the L1A LP turbine blade profile with unsteady wakes. These comparisons were used to determine which RANS CFD model could better predict the unsteady L1A blade flowfield at low inlet Reynolds number. This research also provided further characterization of the Walters and Leylek transitional flow model for low Reynolds number aerodynamic flow prediction in low pressure turbine blades.

Unsteady flow mechanism of the integrated aggressive inter-turbine duct in low Reynolds number condition

2020 ◽  
Vol 234 (9) ◽  
pp. 1507-1517
Author(s):  
Hongrui Liu ◽  
Jun Liu ◽  
Qiang Du ◽  
Guang Liu ◽  
Pei Wang
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Unsteady Flow ◽  
Low Reynolds Number ◽  
Low Pressure ◽  
Tip Clearance ◽  
Surface Boundary ◽  
Suction Surface ◽  
Low Pressure Turbine ◽  
Low Reynolds

Aggressive inter-turbine duct, which has ultra-high bypass ratio and ultra-short axial length, is widely applied in the modern turbofan engine because it can reduce engine weight and improve low-pressure rotor dynamic characteristics. However, the aggressive inter-turbine duct that has swirling flow, wake, shock, and tip clearance leakage flow of upstream high-pressure turbine, and even has structs in its flow channel, is liable to separate, especially in high-altitude low Reynolds number (Re) condition. In addition, its downstream low-pressure turbine is on the edge of separation too. In this paper, an integrated aggressive inter-turbine duct embedded with wide-chord low-pressure turbine nozzle is adopted to eliminate the aggressive inter-turbine duct's end-wall separation. Since there are many studies on suppressing the blade suction surface's separation by upstream wake, in this study inherent wake is utilized to suppress the boundary layer separation on low-pressure turbine nozzle's suction surface in the integrated aggressive inter-turbine duct. The paper studies the unsteady flow mechanisms of the integrated aggressive inter-turbine duct (especially the separation and transition mechanisms of low-pressure turbine nozzle's suction surface boundary layer) by the computatioinal simulation method.

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