A nonaxisymmetric endwall design approach and its computational assessment in the NGV of an HP turbine stage

Turgut, Ozhan; Camcı, Cengiz

doi:10.1016/j.ast.2015.09.014

Cited by 21 publications

(5 citation statements)

References 8 publications

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“…Secondly, these splines are imported into the solid modeling software, in which they are combined to form a three-dimensional contoured endwall. A detailed description of the specific non-axisymmetric endwall contouring design method is given in the previous papers of Turgut and Camci [14] and [25]. In these two papers, analytical details of the contoured endwall generation were presented and computationally evaluated.…”

Section: Design Methodologymentioning

confidence: 99%

A simultaneous use of a leading-edge fillet and a non-axisymmetrically contoured endwall in a turbine stage

Turgut

Camcı

2021

Aerospace Science and Technology

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Section: Design Methodologymentioning

confidence: 99%

A simultaneous use of a leading-edge fillet and a non-axisymmetrically contoured endwall in a turbine stage

Turgut

Camcı

2021

Aerospace Science and Technology

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“…Furthermore, the vortex dissipation in the ITD may result in additional loss, especially for a highly curved duct. 16 Losses caused by some interaction effects, such as rotor-vane interactions, 17,18 wake-shock interactions, 19 and interactions between the blade and the downstream ITD and LPT vane 20 have been fully investigated. For example, it was indicated that losses associated with the wake-shock interactions crossing downstream of the HPT rotor cannot transfer beyond the LPT nozzle.…”

Section: Introductionmentioning

confidence: 99%

Loss evaluation and aerodynamics investigation of an aggressive intermediate turbine duct under off-design conditions

Geng

et al. 2022

Proceedings of the Institution of Mechanical Engineers, Part G:

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To maximize the performance of the intermediate turbine duct (ITD) under off-design conditions, the loss generation in a one-half stage turbine was quantified using entropy generation and the global entropy generation rate. The numerical results solved by the unsteady Reynolds-averaged Navier–Strokes equations were first verified. Then, the aerodynamic losses within the high-pressure turbine stage were evaluated by efficiency loss under nine operating conditions composed of three rotor speeds and three rotor tip gaps. Finally, the disturbance modes caused by the upstream wake were captured by the dynamic mode decomposition method. Different from the influence of tip gaps, losses of the high-pressure turbine and the ITD are due to the swirl angle display an opposite trend. Under the influence of the interaction between the tip leakage flow and the shroud flow of the ITD, the viscous dissipation and turbulent dissipation increase with a larger tip gap owing to the dominant counter-rotating vortices and secondary flow occurring near the upstream of the ITD shroud. In addition, a large gap seems to enlarge the swirl component of the inflow angle, especially over 80% passage height, leading to greater dissipation losses in these areas. At the ITD inlet, two pairs of counter-rotating vortices at the shroud and the hub are, respectively, captured by the axial velocity mode. Large tip gaps enhance endwall vortices near the shroud and make the up vortex pairs merge into one pair.

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“…And, this weakens the strength of the horseshoe vortex by thinning the boundary layer (BL) associated with the vortex region. 14,15 AFC techniques such as endwall fence, 16 3D lean, sweep and bow [17][18][19][20] were applied on gas turbines and a significant reduction in the secondary flow losses were reported. PFC techniques (Table 1) like endwall and tip fillets are preferred because, it does not require an external energy source.…”

Section: Introductionmentioning

confidence: 99%

Effect of fillets on a blade/vane of wave energy harvesting impulse turbine

Maurya¹,

Thandayutham²,

Samad

2022

Proceedings of the Institution of Mechanical Engineers, Part M:

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Fillets on leading edges (LE) of turbine blades alter flow patterns and change the loss profile. A bidirectional flow impulse turbine utilized for harnessing wave energy is introduced and computational fluid dynamics (CFD) was used to perform various analysis. In the present work, fillets of different radii on the leading and trailing edges of both the rotor blade (RB) and guide vane (GV) are modified to study the change in overall performance. After an appropriate gird convergence study, ANSYS-CFX 16.0 solver is used for solving the Reynolds averaged Navier-Stokes (RANS) equations incorporating the k-ω-SST turbulence closure model. The numerical investigations were performed using the high-resolution scheme with the convergence criteria of 10−6 to produce unwavering results. The results show that the boundary layer near the endwall creates flow blockage and losses. Also, the increase in pressure drop due to the thickening of the boundary layers (BLs) across the blade/vane leads to a depletion in the overall performance of the turbine. The rotor and guide vane filleted turbine experience higher losses than the base model due to the radial pressure gradient that is explained with post-processed figures. The concept of fillet shapes has been applied to gas turbines and which improves the performance of the turbine due to a reduction in the secondary flow losses occurring inside the turbine and the same concept has been applied to wave energy air turbine to check its performance based on the losses present across the turbine passage.

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A nonaxisymmetric endwall design approach and its computational assessment in the NGV of an HP turbine stage

Cited by 21 publications

References 8 publications

A simultaneous use of a leading-edge fillet and a non-axisymmetrically contoured endwall in a turbine stage

A simultaneous use of a leading-edge fillet and a non-axisymmetrically contoured endwall in a turbine stage

Loss evaluation and aerodynamics investigation of an aggressive intermediate turbine duct under off-design conditions

Effect of fillets on a blade/vane of wave energy harvesting impulse turbine

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