Ice Accretion Simulation Based on Roughness Extension of Shear Stress Transport $$ \varvec{k} -\varvec{\omega} $$ Turbulence Model

2019 ◽  
pp. 566-578
Author(s):  
Tong Liu ◽  
Jinsheng Cai ◽  
Kun Qu
Keyword(s):  
Shear Stress ◽  
Turbulence Model ◽  
Ice Accretion ◽  
Shear Stress Transport ◽  
Simulation Based

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.

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

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.

Air/mist cooling in a rectangular duct with varying shapes of ribs

2013 ◽  
Vol 228 (11) ◽  
pp. 1925-1935 ◽  
Author(s):  
Fifi NM Elwekeel ◽  
Qun Zheng ◽  
Antar MM Abdala
Keyword(s):  
Shear Stress ◽  
Forced Convection ◽  
Turbulence Model ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Convection Flow ◽  
Uniform Heat Flux ◽  
Rectangular Duct ◽  
Shear Stress Transport ◽  
Mist Cooling

A numerical investigation of turbulent forced convection in a three-dimensional channel with periodic ribs on the lower channel wall is conducted. The lower wall is subjected to a uniform heat flux condition while the upper wall insulated. This study was conducted to investigate the forced convection, flow friction, and performance factor in a horizontal air and air/mist cooled rectangular duct, with various shaped ribs. Calculations are carried out for square ribs (case A), triangular ribs (case B), and trapezoidal ribs (case C and case D) cross sections over a range of Reynolds numbers (8000–20,000), constant mist mass fraction (6%), and fixed rib height and pitch. To investigate turbulence model effects, computations based on a finite volume method are carried out by utilizing three turbulence models: the standard k-ω, Omega Reynolds stress, and shear stress transport turbulence models. The predicted results from using several turbulence models reveal that the shear stress transport turbulence model provides better agreement with available measurements than others. It is found that the average mist cooling enhancement is about 1.8 times. The air/mist provides the higher heat transfer enhancement over air with trapezoidal-shaped ribs (38°, case C).

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