DNS of a Low Pressure Turbine Blade Computed With the Discontinuous Galerkin Method

Author(s):  
Corentin Carton de Wiart ◽  
Koen Hillewaert ◽  
Philippe Geuzaine

The direct numerical simulation of a turbine cascade at Reis = 85000 and Mis = 0.6 has been undertaken using a fourth-order accurate discontinuous Galerkin / symmetric interior penalty method. This method combines the high accuracy, typical of the dedicated academic DNS and LES codes, to the geometrical flexibility of industrial finite volume codes. It also allows for visual inspection of grid resolution, based on the continuity of the computed fields. Finally it attains high serial and parallel performance due to the exploitation of the high locality of the data. For these reasons it is expected that the method will enable the reliably resolved DNS and LES computations in turbomachinery industry. The accuracy with respect to dedicated academic codes is assessed on the computation of the Taylor-Green vortex. For the turbine case, the computed flow fields are compared to those obtained by large eddy simulations using a finite volume solver, and relative costs for a given resolution are estimated.

1993 ◽  
Vol 51 (1-2) ◽  
pp. 325-329
Author(s):  
B. J. Geurts ◽  
J. G. M. Kuerten ◽  
A. W. Vreman ◽  
V. Theofilis ◽  
P. J. Zandbergen

Author(s):  
Yoshinori Ooba ◽  
Hidekazu Kodama ◽  
Chuichi Arakawa ◽  
Yuichi Matsuo ◽  
Hitoshi Fujiwara ◽  
...  

Author(s):  
Yi Lu ◽  
Kai Liu ◽  
W. N. Dawes

During the last decades, the improvements of both computational ability and numerical schemes have stimulated increasing industrial interest in the use of Large Eddy Simulations (LES) for practical engineering flow problems. However, almost all current approches cannot treat complex geometries at affordable cost to enable LES of industrial problems. A robust, parallel and efficient solver using a general unstructured grid & based on high order flux reconstruction formulation, which uses local reconstruction, is compact and written in differential form without a mass matrix, was developed and has proved the ability to get accurate LES results but using RANS scale meshes. This work is aimed at using flux reconstruction method to perform Large Eddy Simulations for complex geometries in more robust and highly efficient way. Both explicit Runge-Kutta method and implicit LU-SGS method are implemented with improvements as solvers for better performance on boundary layer meshes including large aspect ratio cells. The current solver is ported to GPU architectures and speed up ratios of different order accuracy are presented in this work. A local reconstruction method is introduced to generate high order curved boundary from readily available first order meshes. The large eddy simulations for low pressure turbine blade and low pressure turbine blade with endwall are presented in this work, resolved with total number of degree of freedoms up to 34 million to chieve fourth order accuracy using limited computational resource. The results show that this approach has the potential to obtain LES results of real-geometry problems with affordable computational costs.


Author(s):  
Weihao Zhang ◽  
Zhengping Zou ◽  
Kun Zhou ◽  
Huoxing Liu ◽  
Jian Ye

The effects of periodic wakes and inlet freestream turbulence intensity (FSTI) on coherent structures in the boundary layer of a high-lift low-pressure turbine cascade are studied in this paper. Large-eddy simulations (LES) are performed on T106D-EIZ profile at Reynolds number (Re) of 60,154 (based on the chord and outflow velocity). Eight cases, considering FSTI of 0, 2.5%, 5% and 10% as well as the wake reduced frequency (fr) of 0.67, 1.34 and 0.335, are conducted and discussed. The results show that the open separation could be compressed by freestream turbulence to a small extent, whereas, it could be replaced by separation bubbles under wake conditions. Stripe structures and turbulence spots appear in shear layer over the separation bubbles. The increments of wake frequency or FSTI can accelerate the transition progress which result in shorter separation bubbles, meanwhile, emphasize the turbulence spots.


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