Four Decades of Research Into the Augmentation Techniques of Savonius Wind Turbine Rotor

The blade profiles and blade shapes of vertical-axis Savonius wind turbine rotors have undergone a series of changes over the past three decades. Wind turbine aerodynamicists have carried out numerous computational and experimental research to arrive at a suitable rotor blade design configuration so as to harvest maximum energy from the available wind. In most of the studies, the geometric and aerodynamic aspects of the rotor blade design have been reported. Interestingly enough, a couple of review papers got published in the area of Savonius rotors during the last one decade. However, there is not a single piece of literature that gives a comprehensive and a systematic review of Savonius rotor blade profiles and shapes. This paper aims to collate all the research findings related to these blade profiles/shapes and makes an attempt to highlight their features together with future recommendations.

Evolution and Progress in the Development of Savonius Wind Turbine Rotor Blades Profiles and Shapes

Performance evaluation of vent-augmented elliptical-bladed savonius rotors by numerical simulation and wind tunnel experiments

Developments and applications of porous medium combustion: A recent review

The concept of combustion chamber modifications of diesel engines has been attracting much attention in the field of engine research. Many researchers are investigating modified combustion chambers in modern engines because several studies revealed encouraging results: improved brake thermal efficiency (BTE), and reduced brake specific fuel consumption (BSFC), hydrocarbon (HC), carbon monoxides (CO), soot and smoke emissions. However, further investigation is needed into chamber modification vis-a-vis the creation of ordered turbulence, which can help to control nitrogen oxides (NOx) emissions; besides, the rapid turbulence formations on piston crowns lead to impotent tendencies like knocking, system failure and unregulated emissions. A survey of recent studies in the literature has revealed that these chamber modifications can impact positively on air-fuel mixture rates, fluid distribution, heat transfer rates and emission formations. The primary focus of this study is to evaluate engine combustion characteristics,performance and emissions due to chamber modifications by investigating their effect on different chamber profiles and fuels. This critical analysis of these potential combustion factors can be useful to several research groups for understanding the key factors, challenges, and state of art of chamber modifications. It emerges from the literature that these modifications are easily adaptable and can accommodate a variety of research strategies and options. Thus, this review underscores that the continuation of this study should focus on compatible models with multiple advanced combustion strategies and computational tools in order to attain further refinements to the engine outcomes.

Combustion chamber modifications to improve diesel engine performance and reduce emissions: A review

Although considerable progress has already been achieved in the design of wind turbines, the available technical designs are not yet adequate to develop a reliable wind energy converter especially meant for small-scale applications. The Savonius-style wind turbine appears to be particularly promising for the small-scale applications because of its design simplicity, good starting ability, insensitivity to wind directions, relatively low operating speed, low cost and easy installation. However, its efficiency is reported to be inferior as compared to other wind turbines. Aiming for that, a number of investigations have been carried out to increase the performance of this turbine with various blade shapes. In the recent past, investigations with different blade geometries show that an elliptic-bladed turbine has the potential to harness wind energy more efficiently. In view of this, the present study attempts to assess the performance of an elliptic-bladed Savonius-style wind turbine using 2D unsteady simulations. The SST k-ω turbulence model is used to simulate the airflow over the turbine blades. The power and torque coefficients are calculated at rotating conditions, and the results obtained are validated with the wind tunnel experimental data. Both the computational and experimental studies indicate a better performance with the elliptical blades. Further, the present analysis also demonstrates improved flow characteristics of the elliptic-bladed turbine over the conventional semi-circular design.Copyright © 2014 by ASME

Unsteady Flow Analysis Around an Elliptic-Bladed Savonius-Style Wind Turbine

High temperature heat extraction from counterflow porous burner

Two-stage combustion of methane/air is studied experimentally and numerically with a focus on achieving ultralow NOx emissions. The primary flame is a rich premixed flame in the porous medium. The ...

NOx Minimization in Staged Combustion Using Rich Premixed Flame in Porous Media

This paper describes the results of a three-dimensional numerical investigation conducted on an elliptic bladed Savonius-style wind turbine (SSWT) and the flow field around it. The investigation is also enriched by the comparison of the performance and flow characteristics of this turbine to that of a conventional semicircular bladed SSWT. Unsteady Reynolds-Averaged Navier-Stokes equations are solved using a k-ω shear stress transport turbulence model under dynamic conditions. The numerical results indicate the highest power coefficient (CP) of 0.25 for an elliptic bladed SSWT in comparison with 0.21 for a semicircular bladed SSWT. Furthermore, the computational findings are strengthened by the wind tunnel experiments. From both studies, better torque and power characteristics are obtained with the elliptic bladed turbine in comparison with the semicircular bladed turbine. The deviation of computational results from experimental findings for both kinds of turbines is studied here. The flow field in the vicinity of the blades for both the SSWTs has been studied and compared using the parameters, namely velocity, pressure, and turbulent intensity.

Abhisek Banerjee

Papers

Developments and applications of porous medium combustion: A recent review

Unsteady Flow Analysis Around an Elliptic-Bladed Savonius-Style Wind Turbine

High temperature heat extraction from counterflow porous burner

NOx Minimization in Staged Combustion Using Rich Premixed Flame in Porous Media

Performance and flow analysis of an elliptic bladed Savonius-style wind turbine