In the present work, airfoil sections for a 20 kW wind turbine were generated using Multi-Objective Genetic Algorithm. While larger wind turbines have been researched extensively and perfected, SWTs lack improvements in efficiency and capacity factor. However, literature review and trends point out that SWTs are far from fully developed. Small wind turbines (SWTs) are ideal for supplying electricity to small remote communities that do not have grid access. The results show that, due to the implementation of MTs, a considerable increase in the turbine average power is achieved. Second, Blade Element Momentum (BEM) based computations have been performed to investigate the effect of the MT on the wind turbine power output with different wind speed realizations. This airfoil has been selected because it is typically used on wind turbine, such as the 5 MW reference wind turbine of the National Renewable Energy Laboratory (NREL). Firstly, a computational study of a MT mounted on the pressure surface of the airfoil DU91W(2)250 has been carried out and the best case has been found according to the largest lift-to-drag ratio. The aim of the current study is to find the optimal MT size and location to increase airfoil aerodynamic performance and to investigate its influence on the power output of a 5 MW wind turbine. Therefore, a parametric study of a MT mounted on the pressure surface of an airfoil has been carried out. A study to find the optimal position to improve airfoil aerodynamic performance is presented. Microtabs (MT) consist of a small tab placed on the airfoil surface close to the trailing edge and perpendicular to the surface. While on an average there is 26% error in results produced through RANS turbulence models and LES model provide good results but lots of skills and higher computational capacity required. It has been observed that most of the researchers adopt RANS K-ℇ model because of its simplicity and ease of understanding. Selection of turbulence model affects the analysis as each model use different set of boundary conditions.
This paper discussed CFD approaches and various turbulence models used in cold storage air flow evaluation. Selection of the specific turbulence model for particular flow condition is a big bottle-neck. There are various factors which affects the results produced through CFD analysis of air circulation in close environment like cold storage. In designing of various air distributions arrangements in cold storage Computational Fluid Dynamics (CFD) can play a vital role. This particularly suggests that the developed model could be used as a new trend to modify the designs of wind turbine blades.Įxperimental analysis of flow Distribution inside a cold storage is a costly affair, thus many researchers are intensively using computational techniques. Therefore, it was deduced that the benefits of TEF with Micro-Tab were apparent, especially at the lower surface of the airfoil. The results showed that an increase in the maximum lift coefficient by 25% and a delay in the air-flow stall were accomplished due to opposite sign vortices, which was better than the standard airfoil and S-809 with TEF. Finally, the effects of TEF with Micro-Tab on the aerodynamic characteristics of the S-809 with TEF were compared. Different Micro-Tab positions and constant TEF were examined. Thirdly, the influence of TEF with Micro-Tab on the flow behaviors of the airfoil NREL’s S-809 was studied and discussed. As a result, the effect of TEF on air-flow behavior was demonstrated by augmenting the pressure coefficient at the lower surface of the airfoil at flap position 80% chord length (C) and αF = 7.5°. Secondly, the effects of the flap position (H) and deflection angle (αF) on the flow behaviors were investigated. Firstly, a computational fluid dynamics (CFD) model for the airfoil NREL’s S-809 was established, and validated by comparison with previous studies and wind tunnel experimental data. In this paper, an attempt was made to evaluate the influence of TEF with Micro-Tab on the performance of NREL’s S-809 airfoils. In particular, the benefits generated by TEF with Micro-Tab may be of great interest in the design of wind turbine blades.
This study focused mostly on the use of TEF with Micro-Tab in wind turbine blades using NREL’s S-809 as a model airfoil. Moreover, it can also be used to generate more lift and delay the onset of stall. Recently, the Trailing-Edge Flap with Micro-Tab (TEF with Micro-Tab) has been exploited to enhance the performance of wind turbine blades.
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