Large eddy simulation studies on the influence of turbulent inlet conditions on the flow behavior in a mixing tee

2016 ◽  
Vol 298 ◽  
pp. 51-63 ◽  
Author(s):  
Patrick Gauder ◽  
P. Karthick Selvam ◽  
Rudi Kulenovic ◽  
Eckart Laurien
Keyword(s):  
Large Eddy Simulation ◽  
Flow Behavior ◽  
Simulation Studies ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Inlet Conditions

Including the Drag Effects of Canopies: Real Case Large-Eddy Simulation Studies

2012 ◽  
Vol 146 (1) ◽  
pp. 65-80 ◽  
Author(s):  
Pierre Aumond ◽  
Valery Masson ◽  
Christine Lac ◽  
Benoit Gauvreau ◽  
Sylvain Dupont ◽  
...  
Keyword(s):  
Large Eddy Simulation ◽  
Real Case ◽  
Simulation Studies ◽  
Eddy Simulation ◽  
Large Eddy

Large eddy simulation study of turbulent flow around smooth and rough domes

2013 ◽  
Vol 227 (12) ◽  
pp. 2686-2700 ◽  
Author(s):  
N Kharoua ◽  
L Khezzar
Keyword(s):  
Large Eddy Simulation ◽  
Turbulent Flow ◽  
Flow Behavior ◽  
Pressure Coefficient ◽  
Horseshoe Vortex ◽  
Scale Model ◽  
Stream Velocity ◽  
Mean Velocity ◽  
Eddy Simulation ◽  
Large Eddy

Large eddy simulation of turbulent flow around smooth and rough hemispherical domes was conducted. The roughness of the rough dome was generated by a special approach using quadrilateral solid blocks placed alternately on the dome surface. It was shown that this approach is capable of generating the roughness effect with a relative success. The subgrid-scale model based on the transport of the subgrid turbulent kinetic energy was used to account for the small scales effect not resolved by large eddy simulation. The turbulent flow was simulated at a subcritical Reynolds number based on the approach free stream velocity, air properties, and dome diameter of 1.4 × 105. Profiles of mean pressure coefficient, mean velocity, and its root mean square were predicted with good accuracy. The comparison between the two domes showed different flow behavior around them. A flattened horseshoe vortex was observed to develop around the rough dome at larger distance compared with the smooth dome. The separation phenomenon occurs before the apex of the rough dome while for the smooth dome it is shifted forward. The turbulence-affected region in the wake was larger for the rough dome.

Integrated Large Eddy Simulation of Combustor and Turbine Interactions: Effect of Turbine Stage Inlet Condition

2017 ◽  
Author(s):  
Florent Duchaine ◽  
Jérôme Dombard ◽  
Laurent Gicquel ◽  
Charlie Koupper
Keyword(s):  
Large Eddy Simulation ◽  
Combustion Chamber ◽  
Rotor Blade ◽  
Turbine Stage ◽  
High Pressure Turbine ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Stator Vane ◽  
Specific Configuration ◽  
Inlet Conditions

To study the effects of combustion chamber dynamics on a turbine stage aerodynamics and thermal loads, an integrated Large-Eddy Simulation of the FACTOR combustion chamber simulator along with its high pressure turbine stage is performed and compared to a standalone turbine stage computation operated under the same mean conditions. For this specific configuration, results illustrate that the aerodynamic expansion of the turbine stage is almost insensitive to the inlet turbulent conditions. However, the temperature distribution in the turbine passages as well as on the stator vane and rotor blade walls are highly impacted by these inlet conditions: underlying the importance of inlet conditions in turbine stage computations and the potential of integrated combustion chamber / turbine simulations in such a context.

A Method of Measuring Turbulent Flow Structures With Particle Image Velocimetry and Incorporating Into Boundary Conditions of Large Eddy Simulations

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Puxuan Li ◽  
Steve J. Eckels ◽  
Garrett W. Mann ◽  
Ning Zhang
Keyword(s):  
Particle Image Velocimetry ◽  
Large Eddy Simulation ◽  
Boundary Conditions ◽  
Particle Image ◽  
Advantages And Disadvantages ◽  
Eddy Simulation ◽  
Piv Measurement ◽  
Image Velocimetry ◽  
Large Eddy ◽  
Inlet Conditions

The setup of inlet conditions for a large eddy simulation (LES) is a complex and important problem. Normally, there are two methods to generate the inlet conditions for LES, i.e., synthesized turbulence methods and precursor simulation methods. This study presents a new method for determining inlet boundary conditions of LES using particle image velocimetry (PIV). LES shows sensitivity to inlet boundary conditions in the developing region, and this effect can even extend into the fully developed region of the flow. Two kinds of boundary conditions generated from PIV data, i.e., steady spatial distributed inlet (SSDI) and unsteady spatial distributed inlet (USDI), are studied. PIV provides valuable field measurement, but special care is needed to estimate turbulent kinetic energy and turbulent dissipation rate for SSDI. Correlation coefficients are used to analyze the autocorrelation of the PIV data. Different boundary conditions have different influences on LES, and their advantages and disadvantages for turbulence prediction and static pressure prediction are discussed in the paper. Two kinds of LES with different subgrid turbulence models are evaluated: namely dynamic Smagorinsky–Lilly model (Lilly model) and wall modeled large eddy simulation (WMLES model). The performances of these models for flow prediction in a square duct are presented. Furthermore, the LES results are compared with PIV measurement results and Reynolds-stress model (RSM) results at a downstream location for validation.

Inlet conditions for large eddy simulation: A review

2010 ◽  
Vol 39 (4) ◽  
pp. 553-567 ◽  
Author(s):  
G.R. Tabor ◽  
M.H. Baba-Ahmadi
Keyword(s):  
Large Eddy Simulation ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Inlet Conditions

Large Eddy Simulation of a Helical Coil Steam Generator Test Section

2017 ◽  
Author(s):  
Jonathan K. Lai ◽  
Elia Merzari ◽  
Marilyn Delgado ◽  
Samuel J. Lee ◽  
Saya Lee ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Large Eddy Simulation ◽  
Steam Generator ◽  
Test Section ◽  
Helical Coil ◽  
Reynolds Stresses ◽  
Eddy Simulation ◽  
High Heat Transfer ◽  
Large Eddy ◽  
Inlet Conditions

The helical coil steam generator (HCSG) is a compact heat exchanger that can have high heat transfer even when the pressure drop is low. This makes it advantageous in small modular reactors and high-temperature reactor designs. In order to investigate the fluid phenomena around these helical banked tubes, a test section was built at Texas A&M University to represent flow across two half-rods within HCSG. This study focuses on the validation of large eddy simulation (LES) for this particular geometry. Pressure tap and particle image velocimetry (PIV) measurements have been recorded at an inlet Reynolds number of 8643, and both mean and fluctuating data is compared with the numerical results. The highly scalable spectral-element code Nek5000 has been used to produce the LES calculations. First, simulations of varying polynomial order expansions are made to determine the spatial resolution required to capture the turbulent scales. Then, simulations with different inlet conditions are compared with experimental data. The pressure drop shows good agreement with pressure tap measurements while velocity shows similar characteristics with PIV. Furthermore, the components of the Reynolds stresses and modes from proper orthogonal decomposition have been developed to validate the physics captured.

scholarly journals Acoustic and Large Eddy Simulation studies of azimuthal modes in annular combustion chambers

2012 ◽  
Vol 159 (11) ◽  
pp. 3398-3413 ◽  
Author(s):  
Pierre Wolf ◽  
Gabriel Staffelbach ◽  
Laurent Y.M. Gicquel ◽  
Jens-Dominik Müller ◽  
Thierry Poinsot
Keyword(s):  
Large Eddy Simulation ◽  
Simulation Studies ◽  
Combustion Chambers ◽  
Eddy Simulation ◽  
Large Eddy

Prediction of Profile Losses by Means of Large-Eddy Simulation Including Turbulence Modeling Assessment

2017 ◽  
Author(s):  
Karsten Hasselmann ◽  
Stefan aus der Wiesche
Keyword(s):  
Large Eddy Simulation ◽  
Turbulence Modeling ◽  
Flow Behavior ◽  
Reynolds Numbers ◽  
Navier Stokes ◽  
Eddy Simulation ◽  
Unsteady Separation ◽  
Power Spectral ◽  
Large Eddy ◽  
Experimental Values

In this contribution, a Large-Eddy Simulation (LES) analysis was carried out, to get detailed information about the unsteady flow behavior and loss generation in a turbine cascade at moderate Reynolds numbers. A comprehensive comparison study with experimental data was conducted to validate the LES results. Compared to Reynolds averaged Navier-Stokes (RANS) results, the LES shows a much better agreement with the measured values of the profile loss coefficient, downstream velocity profile, and blade pressure distribution. The unsteady separation and reattachment process was covered well by the LES approach. The power spectral density (PSD) profiles at several positions of the downstream wake were compared and analyzed. Although the results of the LES show mainly a good agreement with the experimental values, there are still some deviations at high frequency. In summery the present case study indicates the high potential of LES especially in case of moderate Reynolds numbers with flow separation.

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