A case study on the calibration of the k–ω SST (shear stress transport) turbulence model for small scale wind turbines designed with cambered and symmetrical airfoils

Energy ◽  
2016 ◽  
Vol 97 ◽  
pp. 144-150 ◽  
Author(s):  
P. A. Costa Rocha ◽  
H. H. Barbosa Rocha ◽  
F. O. Moura Carneiro ◽  
M. E. Vieira da Silva ◽  
C. Freitas de Andrade
Keyword(s):  
Shear Stress ◽  
Turbulence Model ◽  
Wind Turbines ◽  
Small Scale ◽  
Shear Stress Transport

k–ω SST (shear stress transport) turbulence model calibration: A case study on a small scale horizontal axis wind turbine

Energy ◽  
2014 ◽  
Vol 65 ◽  
pp. 412-418 ◽  
Author(s):  
P.A. Costa Rocha ◽  
H.H. Barbosa Rocha ◽  
F.O. Moura Carneiro ◽  
M.E. Vieira da Silva ◽  
A. Valente Bueno
Keyword(s):  
Shear Stress ◽  
Wind Turbine ◽  
Turbulence Model ◽  
Model Calibration ◽  
Horizontal Axis ◽  
Small Scale ◽  
Horizontal Axis Wind Turbine ◽  
Shear Stress Transport

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.

Modification of Shear Stress Transport Turbulence Model Using Helicity for Predicting Corner Separation Flow in a Linear Compressor Cascade

2020 ◽  
Vol 142 (2) ◽  
Author(s):  
Yangwei Liu ◽  
Yumeng Tang ◽  
Ashley D. Scillitoe ◽  
Paul G. Tucker
Keyword(s):  
Shear Stress ◽  
Turbulence Model ◽  
Incidence Angle ◽  
Computational Cost ◽  
Separation Flow ◽  
Compressor Cascade ◽  
Production Term ◽  
Corner Separation ◽  
Shear Stress Transport ◽  
Sst Model

Abstract Three-dimensional corner separation significantly affects compressor performance, but turbulence models struggle to predict it accurately. This paper assesses the capability of the original shear stress transport (SST) turbulence model to predict the corner separation in a linear highly loaded prescribed velocity distribution (PVD) compressor cascade. Modifications for streamline curvature, Menter’s production limiter, and the Kato-Launder production term are examined. Comparisons with experimental data show that the original SST model and the SST model with different modifications can predict the corner flow well at an incidence angle of −7 deg, where the corner separation is small. However, all the models overpredict the extent of the flow separation when the corner separation is larger, at an incidence angle of 0 deg. The SST model is then modified using the helicity to take account of the energy backscatter, which previous studies have shown to be important in the corner separation regions of compressors. A Reynolds stress model (RSM) is also used for comparison. By comparing the numerical results with experiments and RSM results, it can be concluded that sensitizing the SST model to helicity can greatly improve the predictive accuracy for simulating the corner separation flow. The accuracy is quite competitive with the RSM, whereas in terms of computational cost and robustness it is superior to the RSM.

scholarly journals Wind Resource Assessment and Economic Viability of Conventional and Unconventional Small Wind Turbines: A Case Study of Maryland

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5874
Author(s):  
Navid Goudarzi ◽  
Kasra Mohammadi ◽  
Alexandra St. St. Pé ◽  
Ruben Delgado ◽  
Weidong Zhu
Keyword(s):  
Power Generation ◽  
Wind Speed ◽  
Wind Turbines ◽  
Payback Period ◽  
Small Scale ◽  
Small Wind Turbines ◽  
Mean Wind Speed ◽  
Wind Resource ◽  
The Impact

Annual mean wind speed distribution models for power generation based on regional wind resource maps are limited by spatial and temporal resolutions. These models, in general, do not consider the impact of local terrain and atmospheric circulations. In this study, long-term five-year wind data at three sites on the North, East, and West of the Baltimore metropolitan area, Maryland, USA are statistically analyzed. The Weibull probability density function was defined based on the observatory data. Despite seasonal and spatial variability in the wind resource, the annual mean wind speed for all sites is around 3 m/s, suggesting the region is not suitable for large-scale power generation. However, it does display a wind power capacity that might allow for non-grid connected small-scale wind turbine applications. Technical and economic performance evaluations of more than 150 conventional small-scale wind turbines showed that an annual capacity factor and electricity production of 11% and 1990 kWh, respectively, are achievable. It results in a payback period of 13 years. Government incentives can improve the economic feasibility and attractiveness of investments in small wind turbines. To reduce the payback period lower than 10 years, modern/unconventional wind harvesting technologies are found to be an appealing option in this region. Key contributions of this work are (1) highlighting the need for studying the urban physics rather than just the regional wind resource maps for wind development projects in the build-environment, (2) illustrating the implementation of this approach in a real case study of Maryland, and (3) utilizing techno-economic data to determine suitable wind harnessing solutions for the studied sites.

scholarly journals How Much Can Small-Scale Wind Energy Production Contribute to Energy Supply in Cities? A Case Study of Berlin

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5523
Author(s):  
Alina Wilke ◽  
Zhiwei Shen ◽  
Matthias Ritter
Keyword(s):  
Wind Energy ◽  
Wind Turbines ◽  
Renewable Resources ◽  
Energy Production ◽  
Economic Feasibility ◽  
Small Scale ◽  
Small Wind Turbines ◽  
Urban Energy ◽  
Complete Framework

In light of the global effort to limit the temperature rise, many cities have undertaken initiatives to become climate-neutral, making decentralized urban energy production more relevant. This paper addresses the potential of urban wind energy production with small wind turbines, using Berlin as an example. A complete framework from data selection to economic feasibility is constructed to enable the empirical assessment of wind energy for individual buildings and Berlin as a whole. Based on a detailed dataset of all buildings and hourly wind speed on a 1 km² grid, the results show that multiple turbines on suitable buildings can significantly contribute to households’ energy consumption but fall short of covering the full demand. For individual households, our economic evaluation strongly recommends the self-consumption of the produced electricity. The findings suggest that while the use of small wind turbines should be continuously encouraged, exploring other renewable resources or combination of wind and photovoltaic energy in the urban environment remains important.

An Improved Shear Stress Transport(SST) Model for High Speed Flows

2012 ◽  
Vol 229-231 ◽  
pp. 625-629
Author(s):  
Jing Yuan Liu ◽  
Wen Qiang Cheng
Keyword(s):  
Boundary Layer ◽  
Shear Stress ◽  
Turbulence Model ◽  
High Speed ◽  
Correction Term ◽  
Plate Boundary ◽  
Experimental Results ◽  
Tvd Scheme ◽  
Shear Stress Transport ◽  
Sst Model

An improved Shear Stress Transport(SST) model, which allows for the compressible corrections, is proposed in this study. Numerical scheme was established by taking advantage of the improved Total Variation Diminishing (TVD) scheme and by applying implicit scheme to the negative source terms of the turbulence model. Hypersonic flat-plate boundary-layer flows and hypersonic compression ramp flows marked with separation, reattachment and shock/boundary-layer interactions are then computed. The comparisons between the computational results, the experimental results and the semi-empirical formulations show that the compressible correction term of the SST turbulence model is the scalar product of the weighted density average of the turbulent fluctuating velocity and the pressure gradients of the average flow field correlation quantities. In addition, for flow with separation and without separation, calculation results of wall pressures, friction coefficients and wall heat transfer rate distributions using the improved model and established scheme agree better with the experimental results than that using the original SST model.

Sign in / Sign up

Export Citation Format

Share Document