Adriane Prisco Petry

Bio: Adriane Prisco Petry is an academic researcher from Universidade Federal do Rio Grande do Sul. The author has contributed to research in topics: Turbulence & Radiative transfer. The author has an hindex of 8, co-authored 34 publications receiving 526 citations.

A review on the performance of Savonius wind turbines

Abstract: This paper presents a review on the performance of Savonius wind turbines. This type of turbine is unusual and its application for obtaining useful energy from air stream is an alternative to the use of conventional wind turbines. Simple construction, high start up and full operation moment, wind acceptance from any direction, low noise and angular velocity in operation, reducing wear on moving parts, are some advantages of using this type of machine. Over the years, numerous adaptations for this device were proposed. The variety of possible configurations of the rotor is another advantage in using such machine. Each different arrangement of Savonius rotor affects its performance. Savonius rotor performance is affected by operational conditions, geometric and air flow parameters. The range of reported values for maximum averaged power coefficient includes values around 0.05–0.30 for most settings. Performance gains of up to 50% for tip speed ratio of maximum averaged power coefficient are also reported with the use of stators. Present article aims to gather relevant information about Savonius turbines, bringing a discussion about their performance. It is intended to provide useful knowledge for future studies.

Wind tunnel experimental analysis of a complex terrain micrositing

Abstract: The technical and economic feasibility of wind energy projects are defined by identifying the correct wind potential in the site and by the technological choice of equipment. The optimal micrositing of wind turbines determines the success of the project. Most current tools are insufficient to evaluate air flow in a complex terrain where wind effects such as acceleration, deceleration are difficult to be predicted The uncertainties related to the energy outcome present an increasing problem as the precision regarding the amount of the energy that may be commercialized is even higher. The combined use of wind tunnel and mesoscale numerical modeling represents the solution for wind power site assessment in a complex terrain. This paper presents a review of the contribution that wind tunnels have recently made for physical modeling of both the velocity field and the turbulence intensity as a methodology for the atmospheric boundary layer study in a complex terrain. Hence, it describes an experimental simulation of the atmospheric boundary layer (ABL) in a wind tunnel over a complex area to characterize the mean flow (detachment and reattachment) and the turbulence intensity with emphasis in the wind energy production. The experiment was conducted in a wind tunnel and employed two terrain categories: Category I – plain terrain and Category III-IV – moderately rough, corresponding, respectively, to the power law exponent p =0.11 and p =0.23. The complex terrain wind profiles were correlated with that in the plain terrain to show the changes of the velocity and show the extension of turbulence wake caused the by variable topography of the area. The measurements of the wind velocity and turbulence intensity were performed with a hot wire anemometry system. Results demonstrate that velocity profile and turbulence intensity profile vary significantly over the complex area, which makes an accurate experimental evaluation necessary to certify the micrositing layout. Power losses due to wake effects can easily reach 20% of the total power, which may make a plant infeasible.

A critical review of vertical axis wind turbines for urban applications

Abstract: Wind energy is one of the most promising renewable energy resources for power generation, and rapid growth has been seen in its acceptance since 2000. The most acceptable classification for wind turbines is by its axis of orientation: Horizontal Axis Wind Turbines (HAWT) and Vertical Axis Wind Turbines (VAWT). HAWTs are used in many countries for medium-to-large scale power projects, and most commercial installations around the globe are solely based on these turbines. On the other hand, HAWTs are not recognized as a viable option to harness the energy of the wind in urban areas, where the wind is less intense, much more chaotic and turbulent. VAWTs are suggested as a better choice for cities and isolated semi-urban areas. Several attributes have been suggested for the large-scale deployment of VAWTs, e.g., good performance under the weak and unstable wind, no noise and safety concerns, and aesthetically sound for integration in urban areas. Significant research has been published on wind turbine technology and resources assessment methodologies, and this review paper is a modest attempt to highlight some of the major developments of VAWTs, with a focus on the integration with urban infrastructure. Several recommendations have been drawn based on the state-of-the-art information on the subject for future studies and acceptance of wind turbines in the urban areas. It was concluded that further research is critical in making VAWTs a viable, dependable, and affordable power generation technology for many low and decentralized power applications.

Atmospheric Stability Affects Wind Turbine Power Collection

Abstract: The power generated by a wind turbine largely depends on the wind speed. During time periods with identical hub-height wind speeds but different shapes to the wind profile, a turbine will produce different amounts of power. This variability may be induced by atmospheric stability, which affects profiles of mean wind speed, direction and turbulence across the rotor disk. Our letter examines turbine power generation data, segregated by atmospheric stability, in order to investigate power performance dependences at a West Coast North American wind farm. The dependence of power on stability is clear, regardless of whether time periods are segregated by three-dimensional turbulence, turbulence intensity or wind shear. The power generated at a given wind speed is higher under stable conditions and lower under strongly convective conditions: average power output differences approach 15%. Wind energy resource assessment and day ahead power forecasting could benefit from increased accuracy if atmospheric stability impacts were measured and appropriately incorporated in power forecasts, e.g., through the generation of power curves based on a range of turbulence regimes.