Scale-Resolving Simulations of Low-Pressure Turbine Cascades With Wall Roughness Using a Spectral-Element Method

Garai, Anirban; Diosady, Laslo T.; Murman, Scott M.; Madavan, Nateri K.

doi:10.1115/gt2018-75982

Cited by 4 publications

(6 citation statements)

References 47 publications

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“…Variable spatial order can be specified over the domain [27]. The solver was validated up to 16 th spacial and temporal order with highly separated turbulent flows [28,29]. Surface roughness is generated using the methodology proposed in Ref.…”

Section: Methodsmentioning

confidence: 99%

Preliminary scale-resolving simulations of laminar-to-turbulent transition in swept-wing flow

Denison

Garai

Murman

2019

AIAA Aviation 2019 Forum

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Swept wings and control surfaces are common elements of modern aircraft, and it has been shown both experimentally and theoretically that laminar-to-turbulent transition of the three-dimensional boundary layer that develops over them is highly sensitive to surface roughness. Numerous studies have been conducted on the effect of discrete roughness elements or distributed roughness elements on swept flow transition, however so far limited computational effort has been dedicated to the study of transition over swept wings with randomly distributed micron-sized roughness. In the present work, we set up to reproduce the extensive experimental data base generated by Dagenhart et al [1] for the infinite swept wing NLF(2)-0415. To this purpose, we perform scale-resolving simulations of flow transition over smooth and rough surfaces using a high-order space-time spectral-element Discontinuous-Galerkin solver. Different types of surface roughnesses are implemented by elastically deforming the original mesh. The study shows that the experimental results cannot be accounted for by a perfectly smooth wing and reveals a strong sensitivity of the transition process to the representation of the surface roughness. The crossflow patterns and transition location approach those measured for some of the surface profiles, however a correlation between the wavenumber spectrum of the surface, grid resolution and boundary layer stability is yet to be established.

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Section: Methodsmentioning

confidence: 99%

Preliminary scale-resolving simulations of laminar-to-turbulent transition in swept-wing flow

Denison

Garai

Murman

2019

AIAA Aviation 2019 Forum

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“…Garai et al [31] used a spectral element discontinuous Galerkin method with up to 16th order accuracy to conduct scale-resolving simulations of an HPT cascade, with focus on comparing natural transition occurring with clean inflow and bypass transition triggered by turbulent inflow. They reported that the turbulent characteristics of the vane boundary layers differed depending on whether the flow had undergone natural or bypass transition.…”

Section: High-pressure Turbinementioning

confidence: 99%

The Current State of High-Fidelity Simulations for Main Gas Path Turbomachinery Components and Their Industrial Impact

Sandberg

Michelassi²

2019

Flow Turbulence Combust

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Over the past two decades high-fidelity simulations have become feasible for most main gas path turbomachinery components. This paper introduces the key challenges of simulating and modelling turbomachinery flows and presents an overview of possible simulation strategies. A comprehensive overview is given of which particular design challenges have to date been addressed by high-fidelity simulations, with a particular focus on high-pressure and centrifugal compressors, and high-pressure and low-pressure turbines. Recommendations are provided for how quality and accuracy can be ensured for high-fidelity simulations, using direct numerical simulations of a low-pressure turbine as a case study. It is argued that industrial impact from high-fidelity simulations can be achieved in two ways, either by conducting design-of-experiment-like studies that can provide designers with insight into certain physical mechanisms and phenomena, or by helping mature and improve lower-order models. The latter is discussed with particular emphasis on recent advances in machine learning for model assessment and improvement, and the potential of one selected data-driven approach is demonstrated on predictions of wake mixing for low-pressure and high-pressure turbines.

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“…Complete details of this test case and the effects of surface roughness are presented in an upcoming article. 25…”

Section: B Low Pressure Turbine Cascadementioning

confidence: 99%

A linear-elasticity solver for higher-order space-time mesh deformation

Diosady

Murman

2018

2018 AIAA Aerospace Sciences Meeting

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A linear-elasticity approach is presented for the generation of meshes appropriate for a higher-order space-time discontinuous finite-element method. The equations of linearelasticity are discretized using a higher-order, spatially-continuous, finite-element method. Given an initial finite-element mesh, and a specified boundary displacement, we solve for the mesh displacements to obtain a higher-order curvilinear mesh. Alternatively, for moving-domain problems we use the linear-elasticity approach to solve for a temporally discontinuous mesh velocity on each time-slab and recover a continuous mesh deformation by integrating the velocity. The applicability of this methodology is presented for several benchmark test cases.

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Scale-Resolving Simulations of Low-Pressure Turbine Cascades With Wall Roughness Using a Spectral-Element Method

Cited by 4 publications

References 47 publications

Preliminary scale-resolving simulations of laminar-to-turbulent transition in swept-wing flow

Preliminary scale-resolving simulations of laminar-to-turbulent transition in swept-wing flow

The Current State of High-Fidelity Simulations for Main Gas Path Turbomachinery Components and Their Industrial Impact

A linear-elasticity solver for higher-order space-time mesh deformation

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