Numerical investigation of wake interaction in a low pressure turbine

1997 ◽  
Author(s):  
Frank Eulitz ◽  
Karl Engel ◽  
Frank Eulitz ◽  
Karl Engel
Keyword(s):  
Numerical Investigation ◽  
Low Pressure ◽  
Low Pressure Turbine ◽  
Wake Interaction

Numerical Investigation of Three-Dimensional Clocking Effects in a Low Pressure Turbine

2003 ◽  
Author(s):  
Andrea Arnone ◽  
Michele Marconcini ◽  
Alberto Scotti Del Greco ◽  
Ennio Spano
Keyword(s):  
Numerical Investigation ◽  
Dimensional Analysis ◽  
Relative Position ◽  
Three Dimensional ◽  
Low Pressure ◽  
Blade Height ◽  
Interaction Mechanisms ◽  
Low Pressure Turbine ◽  
Wake Interaction

One and a half stages of a low pressure turbine were investigated using a three-dimensional, time-accurate, viscous solver. Unsteady analyses were carried out by varying the circumferential relative position of consecutive vanes to study the effects of clocking on performance. Assuming that efficiency improvements by clocking are linked to the wake tangential position with respect to the successive blade, a certain circumferential shift in this position can be observed along the blade height due to blade twist and non-radial stacking, giving different contributions. In order to assess this phenomenon, results from three-dimensional computations were compared with a quasi three-dimensional analysis at mid-span. The effects of clocking on wake interaction mechanisms and unsteady blade loadings are presented and discussed.

Numerical Investigation of Three-Dimensional Clocking Effects in a Low Pressure Turbine

2004 ◽  
Vol 126 (3) ◽  
pp. 375-384 ◽  
Author(s):  
Andrea Arnone ◽  
Michele Marconcini ◽  
Alberto Scotti Del Greco ◽  
Ennio Spano
Keyword(s):  
Numerical Investigation ◽  
Dimensional Analysis ◽  
Relative Position ◽  
Three Dimensional ◽  
Low Pressure ◽  
Blade Height ◽  
Interaction Mechanisms ◽  
Low Pressure Turbine ◽  
Wake Interaction

One and a half stages of a low pressure turbine were investigated using a three-dimensional time-accurate viscous solver. Unsteady analyses were carried out by varying the circumferential relative position of consecutive vanes to study the effects of clocking on performance. Assuming that efficiency improvements by clocking are linked to the wake tangential position with respect to the successive blade, a certain circumferential shift in this position can be observed along the blade height due to blade twist and nonradial stacking, giving different contributions. In order to assess this phenomenon, results from three-dimensional computations were compared with a quasi-three-dimensional analysis at mid-span. The effects of clocking on wake interaction mechanisms and unsteady blade loadings are presented and discussed.

Numerical Investigation of Loss Development in a Low-Pressure Turbine Cascade With Unsteady Inflow and Varying Inlet Endwall Boundary Layer

2021 ◽  
Author(s):  
Tobias Schubert ◽  
Reinhard Niehuis
Keyword(s):  
Boundary Layer ◽  
Low Pressure ◽  
Turbine Cascade ◽  
Time Resolved ◽  
Blade Passage ◽  
Low Pressure Turbine ◽  
Wake Interaction ◽  
Spatial Redistribution ◽  
Unsteady Inflow ◽  
Flow Attenuation

Abstract An investigation of endwall loss development is conducted using the T106A low-pressure turbine cascade. (U)RANS simulations are complemented by measurements under engine relevant flow conditions (M2th = 0.59, Re2th = 2·105). The effects of unsteady inflow conditions and varying inlet endwall boundary layer are compared in terms of secondary flow attenuation downstream of the blade passage, analyzing steady, time-averaged, and time-resolved flow fields. While both measures show similar effects in the turbine exit plane, the upstream loss development throughout the blade passage is quite different. A variation of the endwall boundary layer alters the slope of the axial loss generation beginning around the midpoint of the blade passage. Periodically incoming wakes, however, cause a spatial redistribution of the loss generation with a premature loss increase due to wake interaction in the front part of the passage followed by an attenuation of the profile- and secondary loss generation in the aft section of the blade passage. Ultimately, this leads to a convergence of the downstream loss values in the steady and unsteady inflow cases.

scholarly journals Numerical Investigation of Wake Interaction in a Low Pressure Turbine

1998 ◽  
Author(s):  
Frank Eulitz ◽  
Karl Engel
Keyword(s):  
Phenomenological Study ◽  
Separated Flow ◽  
Low Pressure ◽  
Skin Friction Coefficient ◽  
Boundary Layer Transition ◽  
Navier Stokes ◽  
Layer Transition ◽  
Low Pressure Turbine ◽  
Wake Interaction ◽  
Large Fluctuations

A time-accurate Reynolds-averaged Navier-Stokes solver has been extended for a phenomenological study of wake/bladerow interaction in a low pressure turbine near midspan. To qualitatively account for unsteady laminar-turbulent boundary layer transition, a variant of the Abu-Ghanam Shaw transition correlation has been coupled with the Spalart-Allmaras one-equation turbulence model. The method is shown to be capable of capturing separated-flow and wake-induced transition, as well as becalming and relaminarization effects. The model turbine investigated consists of three stator and two rotor rows. Instantaneous Mach number and eddy-viscosity plots are presented to monitor the wake migration and interaction with downstream boundary layers. Especially on the suction sides, very large fluctuations of the skin friction coefficient are observed. Effects of the near and far wakes are identified.

Numerical Investigation of Airfoil Clocking in a Three-Stage Low Pressure Turbine

2001 ◽  
Author(s):  
Andrea Arnone ◽  
Michele Marconcini ◽  
Roberto Pacciani ◽  
Claudia Schipani ◽  
Ennio Spano
Keyword(s):  
Reynolds Number ◽  
Numerical Investigation ◽  
Relative Position ◽  
Low Reynolds Number ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Low Pressure Turbine ◽  
Wake Interaction ◽  
Low Reynolds ◽  
Lp Turbine

A quasi–three–dimensional, blade–to–blade, time–accurate, viscous solver w as used for a three–stage LP turbine study Due to the low Reynolds number, transitional computations were performed. Unsteady analyses were then carried out by varying the circumferential relative position of consecutive vanes and blade rows to study the effects of clocking on the turbine’s performance. A clocking strategy developed in order to limit the number of configurations to be analyzed is discussed. The optimum analytically–determined clocking position is illustrated for two different operating conditions, referred to as cruise and takeoff. The effects of clocking on wake interaction mechanisms and unsteady blade loadings is presented and discussed. For low Reynolds number turbine flows, the importance of taking transition into account in clocking analysis is demonstrated by a comparison with a fully turbulent approach.

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