Assessment of stress-blended eddy simulation model for accurate performance prediction of vertical axis wind turbine

Abstract

Purpose The aim of this paper is to assess the ability of a stress-blended eddy simulation (SBES) turbulence model to predict the performance of a three-straight-bladed vertical axis wind turbine (VAWT). The grid sensitivity study is conducted to evaluate the simulation accuracy. Design/methodology/approach The unsteady Reynolds-averaged Navier–Stokes equations are solved using the computational fluid dynamics (CFD) technique. Two types of grid topology around the blades, namely, O-grid (OG) and C-grid (CG) types, are considered for grid sensitivity studies. Findings With regard to the power coefficient (Cp), simulation results have shown significant improvements of predictions using compared to other turbulence models such as the k-e model. The Cp distributions predicted by applying the CG mesh are in good agreement with the experimental data than that by the OG mesh. Research limitations/implications The current study provides some new insights of the use of SBES turbulence model in VAWT CFD simulations. Practical implications The SBES turbulence model can significantly improve the numerical accuracy on predicting the VAWT performance at a lower tip speed ratio (TSR), which other turbulence models cannot achieve. Furthermore, it has less computational demand for the finer grid resolution used in the RANS-Large Eddy Simulation (LES) “transition” zone compared to other hybrid RANS-LES models. Originality/value To authors’ knowledge, this is the first attempt to apply SBES turbulence model to predict VAWT performance resulting for accurate CFD results. The better prediction can increase the credibility of computational evaluation of a new or an improved configuration of VAWT.

Near Stall Unsteady Flow Responses to Morphing Flap Deflections

“…More recently, Syawitri el al. [26] and Rezaeiha et al [27] both used SBES to predict the aerodynamic performance of vertical axis wind turbines (VAWTs). More importantly, Syawitri el al.…”

“…More importantly, Syawitri el al. [26] showed that it is possible to significantly improve the numerical prediction of the flow around a 2D VAWT with three straight blades using SBES, while still accurately predicting the flow field. Rezaeiha et al [27] demonstrated that 2.5D SBES is a superior approach to both URANS and scale-adaptive simulation (SAS).…”

Calculation and analysis of thermal flow field in hydrodynamic torque converter with a new developed stress-blended eddy simulation

“…An improved CFD with a dynamic modified viscosity coefficient (Umavathi and Ojjela, 2015;Umavathi, 2015) could accurately identify the flows in detail between the viscous sublayer and outer boundary layer. The stress-blended eddy simulation model (SBES), which was further employed to achieve the blending on the stress level (Syawitri et al, 2020), has enough sensitivity to capture the information of the flow field in detail. The effectiveness and superiority of SBES in the dynamic hybrid RANS/LES model is verified on vertical axis wind turbines (Rezaeiha et al, 2019) and flow around cylinder (Dorogi and Baranyi, 2020).…”

“…Nonetheless, present computational fluid dynamics methods inadequately distinguish the discernable flows in detail. A multiphysical field coupling model, which was applied in rotor-stator fluid machinery (Umavathi, 2015;Syawitri et al, 2020), was put forward to ensure the identification of multi-scale vortexes and the improvement of performance prediction in torque converter.Design/methodology/approach -A newly-developed multi-physical field simulation framework that coupled the scale-resolving simulation method with a dynamic modified viscosity coefficient was proposed to comparatively investigate the influence of energy exchange on thermal and flow characteristics and the description of the flow field in detail.Findings -Regardless of whether quantitative or qualitative, its description ability on turbulence statistics, pressure-streamline, vortex structure and eddy viscosity ratio were visually experimentally and numerically analyzed. The results revealed that the modification of transmission medium viscous can identify flows more exactly between the viscous sublayer and outer boundary layer.…”

“…Nonetheless, present computational fluid dynamics methods inadequately distinguish the discernable flows in detail. A multiphysical field coupling model, which was applied in rotor-stator fluid machinery (Umavathi, 2015;Syawitri et al, 2020), was put forward to ensure the identification of multi-scale vortexes and the improvement of performance prediction in torque converter.…”