Search results for "Vertical axis"
showing 6 items of 6 documents
Simulated 3-axis versus 5-axis Processing Toolpaths for Single Point Incremental Forming
2019
Abstract Accuracy and productivity of the parts manufactured by single point incremental forming (SPIF) are influenced by the proper selection of toolpaths. CAM software packages are often used for generating the toolpaths for the process. Literature survey have revealed that contour curves and spatial spirals are the most used toolpaths for SPIF. These toolpaths are generated using 3-axis approaches, meaning that the tool axis is maintained parallel to the vertical axis. The 3-axis approach was justified using 3-axis CNC milling machines as the main technological equipment for SPIF. However, nowadays, the wide spreading of both 5-axis CNC milling machines and industrial robots, with far su…
Spinopelvic changes based on the simplified SRS-Schwab adult spinal deformity classification: relationships with disability and health-related qualit…
2018
Study design Cross-sectional, observational study. Objective To study the occurrence of sagittal malalignment, the adaptability of a simplified sagittal modifiers grading of the Scoliosis Research Society (SRS)-Schwab adult spinal deformity (ASD) classification, and the deformity-specific SRS questionnaire version 30 (SRS-30) in an unselected adult cohort with symptomatic degenerative spinal disorders. Summary of background data The sagittal modifiers of the SRS-Schwab ASD classification correlate with health-related quality of life (HRQoL) measures in patients with ASD. The deformities and disabilities caused by sagittal malalignment in patients with common degenerative spinal disorders of…
Wind tunnel testing, numerical analyses and shape optimization of a vertical axis wind turbine
2011
In this work the aerodynamic efficiency of a small commercial vertical axis wind turbine is investigated experimentally and numerically. The turbine is a Darrieus type with three vertical airfoil blades having helical twist of 78 degrees, height 1.45m and diameter of 1.45m. The airfoils have a chord of 222 mm and a thickness of 35 mm. The experimental studies were made in a wind tunnel where a hot-wire anemometer was used to measure the wind speed. The power curves of the turbine were extracted using a generator connected with an inverter able to vary the resistant moment applied to the turbine and to measure its resulting angular speed. The energy produced by the turbine itself at various …
Modern small wind turbine design solutions comparison in terms of estimated cost to energy output ratio
2015
This paper presents a series of estimations performed in order to establish the actual cost-effectiveness of three different small wind turbines (SWTs) design solutions. Each of them was evaluated and based on their power curves and installation costs, using wind data from a numerical weather prediction (WNP) model, a return on investment (ROI) period was calculated. The chosen turbines are: a standard three bladed horizontal axis wind turbine (HAWT), an advanced diffuser augmented HAWT and a Darrieus type vertical axis wind turbine (VAWT). The conclusions drawn from this study entertain the idea that from the economical point of view, a price reduction of SWT systems is more important than…
Flow characteristics and dynamic responses of a parked straight‐bladed vertical axis wind turbine
2019
Abstract With the development of urbanization and the application of renewable energy, wind turbine is becoming an important approach for wind energy reservation and utilization. This study provides a numerical investigation on understanding the surface pressure distribution, flow characteristics and dynamic responses of a parked straight‐bladed vertical axis wind turbine (VAWT), which is helpful for its design. Together with the two‐way coupling method between simulation platforms such as STAR‐CCM+ and ABAQUS, the SST k‐ω turbulence model is used to obtain the surface pressure and surrounding flow of the VAWT, and the finite element method is used to obtain the dynamic responses of its str…
Implementation and application of the actuator line model by OpenFOAM for a vertical axis wind turbine
2017
University of Stavanger has started The Smart Sustainable Campus & Energy Lab project, to gain knowledge and facilitate project based education in the field of renewable and sustainable energy and increase the research effort in the same area. This project includes the future installation of a vertical axis wind turbine on the campus roof. A newly developed Computational Fluid Dynamics (CFD) model by OpenFOAM have been implemented to study the wind behavior over the building and the turbine performance. The online available wind turbine model case from Bachant, Goude and Wosnik from 2016 is used as the starting point. This is a Reynolds-Averaged Navier-Stokes equations (RANS) case set up th…