The Reynolds Stress Model (RSM) is adopted to simulate the wind turbine wake and the simulation results are compared with the wind tunnel test data, simulation results from the standard k-ε model and a modified k-ε model. RSM shows good performance in predicting the turbine wakes velocity, turbulence intensity and the kinetic shear stress, while the k-ε based models fail to predict either wakes...

Over the centuries, energy has been supplied by wood, coke, coal, oil and natural gas, as well as by uranium (nuclear energy). All these energy sources are limited and at the same time these energy sources create pollution problems. This has led to the focus on a sustainable energy supply, which implies optimized use of energy, minimized pollution. That is why wind energy is prominent and it is...

OBJECTIVES To evaluate the prevalence of perception and annoyance due to wind turbine noise among people living near the turbines, and to study relations between noise and perception/annoyance, with focus on differences between living environments. METHODS A cross-sectional study was carried out in seven areas in Sweden across dissimilar terrain and different degrees of urbanisation. A postal...

(UC Berkeley/LBNL) for embarking on the initial analysis that formed the basis for this report, Eric Lantz (NREL) for guidance on the use of NREL's turbine cost and scaling model, and Naïm Darghouth (LBNL) for compiling data on wind turbine imports. The authors would also like to thank the following individuals for reviewing earlier drafts of this manuscript: and several anonymous reviewers. Of...

The anti-suck-back ability of five new high-speed air turbine handpiece models was evaluated in this study. First, suck-back pressure with water displacement within a glass tube was measured. Next, under three different conditions, how many on-off times it takes before fluorescent stains became visible on a piece of gauze at the exhaust vent was counted and the presence of fluorescent stains on...

Inadequate design and improper mixing operation in anaerobic digesters often lead to poor mixing and digester failures due to the presence of dead zones formed in the digester. More research is required to understand the mixing phenomena in anaerobic digesters and thus improve their efficiency. This paper investigates the efficiency of mixing of digester sludge in a mechanically agitated vessel...

A computational fluid dynamics simulation is done for non-Newtonian fluid in a baffled stirred tank. The CMC solution is taken as non-Newtonian shear thinning fluid for simulation. The Reynolds Average Navier Stocks equation with steady state multi reference frame approach is used to simulate flow in the stirred tank. The turbulent flow field is modelled using realizable k-ε turbulence model. T...

When studying flow phenomena in a scaled laboratory experiment or in a computational simulation, it is often not possible to achieve dynamic similarity with the fullscale flow of interest. In the case of wind and water turbine experiments, a scaled model turbine may not perform as well as in the field, or perhaps not at all, due to a mismatch of Reynolds number and other scaling difficulties su...

In a wind turbine system, blades are one of the most critical components. They capture energy from wind and convert it to a mechanical energy for electricity power generation. However, once the blades are defective, the power generation efficiency of the turbine will be significantly affected. In worse case when the blade is seriously damaged, the turbine will have to be shut down completely fo...

Power system is a combination of a number of sources and loads properly linked by a transmission system. The source is a generating system fueled by renewable or non renewable system where bio mass fuel is used to generate electric power. Due to low levels of bio fuel availability, the gas turbine system is considered as a weak system when compared to thermal and hydro systems. However, stable ...