Estimation of Wind Turbulence Model Parameters

2005 ◽  
Author(s):  
M. Jelavic ◽  
N. Peric ◽  
S. Car
Keyword(s):  
Turbulence Model ◽  
Model Parameters ◽  
Wind Turbulence

Sensitivity Studies of Shear Stress Transport Turbulence Model Parameters on the Prediction of Seven-Rod Bundle Benchmark Experiments

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Cale Bergmann ◽  
S. Ormiston ◽  
V. Chatoorgoon
Keyword(s):  
Shear Stress ◽  
Turbulence Model ◽  
Turbulence Modeling ◽  
Sensitivity Study ◽  
Model Parameters ◽  
Rod Bundle ◽  
Shear Stress Transport ◽  
Sst Turbulence Model ◽  
Sensitivity Studies ◽  
Two Parameters

This paper reports the findings of a sensitivity study of parameters in the shear stress transport (SST) turbulence model in a commercial computational fluid dynamics (CFD) code to predict an experiment from the Generation IV International Forum Supercritical-Water-Cooled Reactor (GIF SCWR) 2013–2014 seven-rod subchannel benchmark exercise. This study was motivated by the result of the benchmark exercise that all the CFD codes gave similar results to a subchannel code, which does not possess any sophisticated turbulence modeling. Initial findings were that the CFD codes generally underpredicted the wall temperatures on the B2 case in the region where the flow was supercritical. Therefore, it was decided to examine the effect of various turbulence model parameters to determine if a CFD code using the SST turbulence model could do a better job overall in predicting the wall temperatures of the benchmark experiments. A sensitivity study of seven parameters was done, and changes to two parameters were found to make an improvement.

scholarly journals A k–ε Turbulence Model for the Convective Atmosphere

2020 ◽  
Vol 77 (11) ◽  
pp. 3891-3906
Author(s):  
Xiping Zeng ◽  
Yansen Wang
Keyword(s):  
Turbulence Model ◽  
Friction Velocity ◽  
Wind Profile ◽  
Similarity Theory ◽  
Ground Surface ◽  
Geostrophic Wind ◽  
Model Parameters ◽  
Transition Model ◽  
Atmospheric Boundary Layers ◽  
Obukhov Length

AbstractA k–ε turbulence model for the stable atmosphere is extended for the convective atmosphere. The new model represents the buoyancy-induced increase in the kinetic energy and scale of eddies, and is consistent with the Monin–Obukhov similarity theory for convective atmospheric boundary layers (ABLs). After being incorporated into an ABL model with the Coriolis force, the model is tested by comparing the ABL model results with the Businger–Dyer (BD) relationship. ABL model simulations are carried out to reveal the sensitivity of the vertical wind profile to model parameters (e.g., the Obukhov length, friction velocity, and geostrophic wind). When the friction velocity is consistent with geostrophic wind speed (or the turbulence in the inner regime is in equilibrium with that in the outer regime), the modeled wind profile is close to the BD relationship near the ground surface. Otherwise, the modeled wind profile deviates from the BD relationship, resembling the hockey stick transition model.

scholarly journals ASSESSMENT OF IEC 61400-1 NORMAL TURBULENCE MODEL FOR WIND CONDITIONS IN TAIWAN WEST COAST AREAS

2014 ◽  
Vol 34 ◽  
pp. 1460382 ◽  
Author(s):  
TZONG-SHYNG LEU ◽  
JUI-MING YO ◽  
YI-TING TSAI ◽  
JIU-JIH MIAU ◽  
TA-CHUNG WANG ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Turbulence Model ◽  
West Coast ◽  
Wind Farms ◽  
Offshore Wind ◽  
Wind Data ◽  
Model Parameters ◽  
Observation Data ◽  
Offshore Wind Farms ◽  
Proposed Model

This paper studies the applicability of Normal Turbulence Model (NTM) in IEC61400-1 for wind conditions in Taiwan west coast area where future offshore wind farms are planning in the nearby areas. The parameters for the standard deviation of wind fluctuating [Formula: see text] are presented and compared with IEC Normal Turbulence Model. It is found that the trend of turbulence standard deviation [Formula: see text] based on the observation data agreed qualitatively well with IEC Normal Turbulence Model. However, IEC Normal Turbulence Model results in rather small [Formula: see text] compared to surveillance wind data in Taiwan. In this paper, model parameters for [Formula: see text] and [Formula: see text] based on the two-year observation wind data are proposed. The proposed model parameters a, b, α and β are 0.9125, 2.4345, 0.097 and 2.1875.

Determination of integral turbulence model parameters as applied to calculation of rod-bundle flows in porous-body approximation

2016 ◽  
Vol 23 (2) ◽  
pp. 201-209 ◽  
Author(s):  
M. N. Vlasov ◽  
A. S. Korsun ◽  
Yu. A. Maslov ◽  
I. G. Merinov ◽  
V. I. Rachkov ◽  
...  
Keyword(s):  
Turbulence Model ◽  
Porous Body ◽  
Model Parameters ◽  
Rod Bundle
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