Computational Fluid Dynamics for urban physics: Importance, scales, possibilities, limitations and ten tips and tricks towards accurate and reliable simulations

Natural-gas fueled spark-ignition (SI) and compression-ignition (CI) engine performance and emissions

50 years of Computational Wind Engineering: Past, present and future

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

In recent years, with the advent of globalization, the world is witnessing a steep rise in its energy consumption. The world is transforming itself into an industrial and knowledge society from an agricultural one which in turn makes the growth, energy intensive resulting in emissions. Energy modeling and energy planning is vital for the future economic prosperity and environmental security. Soft computing techniques such as fuzzy logic, neural networks, genetic algorithms are being adopted in energy modeling to precisely map the energy systems. In this paper, an attempt has been made to review the applications of fuzzy logic based models in renewable energy systems namely solar, wind, bio-energy, micro-grid and hybrid applications. It is found that fuzzy based models are extensively used in recent years for site assessment, for installing of photovoltaic/wind farms, power point tracking in solar photovoltaic/wind, optimization among conflicting criteria. The review indicates that fuzzy based models provide realistic estimates.

Applications of fuzzy logic in renewable energy systems – A review

This study is focused on exploring the utilization of non-edible straight vegetable oil, derived from the seed of Mesua ferrea Linn, to supplement the fuel requirement of a stationary compression ignition (CI) diesel engine, through blending with the diesel. Three vegetable oil (VO) blends VO10, VO20 and VO30 having 10, 20 and 30% VO by volume have been used in the experimental investigation. The experiments are conducted in a single-cylinder, four-stroke, water cooled, naturally aspirated, direct injection, variable compression ratio CI engine. The study reveals a reduction in the brake thermal of efficiency (BTE) and increase in brake specific fuel consumption (BSFC) with the use of VO blends. The emissions of carbon monoxide (CO) and hydrocarbon (HC) also increase with the increase in the content of VO in the blend, while oxides of nitrogen (NOx) decreases with blending. The VO10 shows a comparable performance with that of the diesel in the CI engine. The maximum drop in the BTE of VO10 is found to be 1.78%; while CO and NOx emissions are found to be lower in comparison to that of diesel.

Implications of blended Mesua ferrea Linn oil on performance, combustion and emissions of compression ignition diesel engines

Study of bed-to-wall heat transfer with twisted tape at the upper splash region of a pressurized circulating fluidized bed unit

Assessment of a Syngas-Diesel Dual Fuelled Compression Ignition Engine

In this study, Mesua ferrea Linn oil (VO, 30% by volume)-diesel (70% by volume) blend (VO30) is used as the fuel to power a direct-injection (DI), single-cylinder compression ignition (CI) diesel engine. This study is focused on the effects of diethyl ether (DEE) as an additive on the performance, combustion and emission characteristics of the engine fuelled by the VO30 blend. DEE is added to the VO30 blend to form two types of ternary blend. One consists of 5% DEE and 95% VO30 by volume (VO30DEE05) and the other consists of 10% DEE and 90% VO30 by volume (VO30DEE10). The study reveals an improvement of 1% to 2.3% in engine thermal efficiency with the use of diethyl ether as additives to the VO-diesel blend. In the same line, both the CO and NOx emission also decreases with the use of DEE additives with the VO-diesel blend. A maximum reduction of 6.9% to 13% CO emission and 3.2% to 11.9% NOx has been achieved with DEE additives as compared to VO30 fuel. The work suggests that DEE can be used effectively as an additive to VO30 fuel which can run CI diesel engines with improved thermal efficiency and reduced emissions.

Increase of efficiency and reduction of CO and NOx emissions in a stationary compression ignition engine run on Mesua ferrea Linn oil-diesel and diethyl ether

In the context of energy crisis, extensive depletion of fossil fuel, and climate change, the vertical-axis Savonius-type wind or hydrokinetic turbines appear to be promising candidates to extract energy from wind or free-flowing water because of their superior self-starting capability and design simplicity. The present investigation focuses on comparative analysis between Savonius wind turbines (SWTs) and Savonius hydrokinetic turbines (SHTs) at the same input power. To accomplish this, two configurations are considered, viz., 2-bladed and 3-bladed turbine designs having semicircular blade profiles. Experimental studies revealed that the SWTs operate in a slightly wider range of tip-speed ratios than the SHTs. It is also observed that, like SHTs, 2-bladed SWTs result in an improved (47%) peak power coefficient (CPmax) than 3-bladed SWTs. In line with this, the computational studies, conducted to complement the experimental analysis, showed the superiority of 2-bladed SWTs over the 3-bladed SWTs. Both experimental and computational analyses reveal that the SHTs and SWTs show identical drag and lift characteristics for given kinetic energy of the inlet fluid stream.

Ujjwal K. Saha

Papers

Implications of blended Mesua ferrea Linn oil on performance, combustion and emissions of compression ignition diesel engines

Study of bed-to-wall heat transfer with twisted tape at the upper splash region of a pressurized circulating fluidized bed unit

Assessment of a Syngas-Diesel Dual Fuelled Compression Ignition Engine

Increase of efficiency and reduction of CO and NOx emissions in a stationary compression ignition engine run on Mesua ferrea Linn oil-diesel and diethyl ether

Performance estimation of Savonius wind and Savonius hydrokinetic turbines under identical power input