Wind energy is the fastest growing alternate source of energy in the world since its purely economic potential is complemented by its great positive environmental impact. The wind turbine, whether it may be a Horizontal-Axis Wind Turbine (HAWT) or a Vertical-Axis Wind Turbine (VAWT), offers a practical way to convert the wind energy into electrical or mechanical energy. Although this book focuses on the aerodynamic design and performance of VAWTs based on the Darrieus concept, it also discusses the comparison between HAWTs and VAWTs, future trends in design and the inherent socio-economic and environmental friendly aspects of wind energy as an alternate source of energy.

Wind turbine design with emphasis on Darrieus concept Ion Paraschivoiu

Knocking combustion in spark-ignition engines

The Darrieus wind turbine: Proposal for a new performance prediction model based on CFD

A modified fuzzy-logic controller for maximum power point (MPP) tracking is proposed to increase photovoltaic (PV) system performance during partially shaded conditions. Instead of perturbing and observing the PV system MPP, the controller scans and stores the maximum power during the perturbing and observing procedures. The controller offers accurate convergence to the global maximum operating point under different partial shadowing conditions. A mathematical model of the PV system under partial shadowing conditions is derived. To validate the proposed modified fuzzy-logic-based controller, simulation and experimentation results are provided.

A Maximum Power Point Tracking Technique for Partially Shaded Photovoltaic Systems in Microgrids

The engine knock analysis – An overview

Fluid dynamics wind turbine design: Critical analysis, optimization and application of BEM theory

https://cyberleninka.org/article/n/450829.pdf

2D CFD Modeling of H-Darrieus Wind Turbines Using a Transition Turbulence Model

Wind turbine CFD modeling using a correlation-based transitional model

This work analyses the link between the aspect ratio of a vertical-axis straight-bladed (H-Rotor) wind turbine and its performance (power coefficient). The aspect ratio of this particular wind turbine is defined as the ratio between blade length and rotor radius. Since the aspect ratio variations of a vertical-axis wind turbine cause Reynolds number variations, any changes in the power coefficient can also be studied to derive how aspect ratio variations affect turbine performance. Using a calculation code based on the Multiple Stream Tube Model, symmetrical straight-bladed wind turbine performance was evaluated as aspect ratio varied. This numerical analysis highlighted how turbine performance is strongly influenced by the Reynolds number of the rotor blade. From a geometrical point of view, as aspect ratio falls, the Reynolds number rises which improves wind turbine performance.

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Design of a vertical-axis wind turbine: how the aspect ratio affects the turbine’s performance

Though analysed by a few researches, the practice of water injection in Spark Ignition Engines (SI-ICE) does not yield homogeneous results, owing to various typologies of engines used for experiments. In this paper the effects of water injection in the intake pipe are investigated from both a theoretical and experimental viewpoint. Pressure vs. time diagrams were recorded on a single-cylinder CFR engine at AGIP PETROLI, Priolo (CT). Tests were performed according to Research and Motor Method (ASTM). Water was supplied by a continuous injection system inclusive of comparatively high pressure pump. The engine was fed with low O.N. base gasoline (cheap products, intermediate of refinery processes). The water to fuel mass flow rate ratio was varied in the range 0 to 1.5. The NOx emissions measurements confirm the tremendous effectiveness of water injection in reducing the engine environmental impact. Test data have been used to implement a detonation model that allows to predict water injection effects. Results have shown that water injection really represents a new way to avoid detonation, to reduce compression work and to control NOx formation in SI engines.

Rosario Lanzafame

Papers

Fluid dynamics wind turbine design: Critical analysis, optimization and application of BEM theory

2D CFD Modeling of H-Darrieus Wind Turbines Using a Transition Turbulence Model

Wind turbine CFD modeling using a correlation-based transitional model

Design of a vertical-axis wind turbine: how the aspect ratio affects the turbine’s performance

Water Injection Effects In A Single-Cylinder CFR Engine