Numerical Model of Flow Field Around a Horizontal Axis Tidal Stream Turbine With a Mono-Pile Foundation

2015 ◽  
Author(s):  
Fan Song ◽  
Jinhai Zheng ◽  
Cong Ding ◽  
Jisheng Zhang ◽  
Yuxuan Peng
Keyword(s):  
Numerical Model ◽  
Flow Field ◽  
Pile Foundation ◽  
High Efficiency ◽  
Flow Speed ◽  
Horizontal Axis ◽  
Complex Flow ◽  
Low Velocity ◽  
Tidal Stream ◽  
Tidal Stream Turbine

The horizontal axis tidal stream turbine with a mono-pile foundation is one of the most used devices for the exploitation of tidal stream energy, because of its convenience and low expense in construction and high efficiency in extracting energy. A 3D hydrodynamic model is developed to investigate flow field around the tidal stream turbine subjected to a steady current. After verified with the previous experimental works, the numerical model is used to study the complex flow motion around the horizontal axis tidal stream turbine with a mono-pile foundation. The numerical results show that the existence of tidal stream turbine may largely change the flow dynamics. A wake region with low velocity is formed behind the device. Water surface in front of the turbine fluctuates periodically. It is also found that the installing elevation of the turbine and the incoming flow speed have significant impacts on the mean kinetic energy and the resulting fluid force of the rotating turbine.

Scour around a mono-pile foundation of a horizontal axis tidal stream turbine under steady current

2019 ◽  
Vol 192 ◽  
pp. 106571 ◽  
Author(s):  
Xiangfeng Lin ◽  
Jisheng Zhang ◽  
Risheng Wang ◽  
Jing Zhang ◽  
Wei Liu ◽  
...  
Keyword(s):  
Pile Foundation ◽  
Horizontal Axis ◽  
Steady Current ◽  
Tidal Stream ◽  
Tidal Stream Turbine

Experimental study of the wake homogeneity evolution behind a horizontal axis tidal stream turbine

2021 ◽  
Vol 111 ◽  
pp. 102644
Author(s):  
Zhi Zhang ◽  
Yuquan Zhang ◽  
Jisheng Zhang ◽  
Yuan Zheng ◽  
Wei Zang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Horizontal Axis ◽  
Tidal Stream ◽  
Tidal Stream Turbine

scholarly journals Experimental study of wake structure behind a horizontal axis tidal stream turbine

2017 ◽  
Vol 196 ◽  
pp. 82-96 ◽  
Author(s):  
Yaling Chen ◽  
Binliang Lin ◽  
Jie Lin ◽  
Shujie Wang
Keyword(s):  
Experimental Study ◽  
Horizontal Axis ◽  
Wake Structure ◽  
Tidal Stream ◽  
Tidal Stream Turbine

Experimental study on kinetic energy conversion of horizontal axis tidal stream turbine

2016 ◽  
Vol 97 ◽  
pp. 784-797 ◽  
Author(s):  
Jeonghwa Seo ◽  
Seung-Jae Lee ◽  
Woo-Sik Choi ◽  
Sung Taek Park ◽  
Shin Hyung Rhee
Keyword(s):  
Experimental Study ◽  
Kinetic Energy ◽  
Energy Conversion ◽  
Horizontal Axis ◽  
Tidal Stream ◽  
Tidal Stream Turbine

scholarly journals Gravitational Focusing of Low-Velocity Dark Matter on the Earth’s Surface

Galaxies ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 42 ◽  
Author(s):  
Yoshiaki Sofue
Keyword(s):  
Dark Matter ◽  
Solar System ◽  
High Efficiency ◽  
Focal Point ◽  
Flow Speed ◽  
Low Velocity ◽  
The Earth ◽  
Velocity Flow ◽  
Solar System Objects

We show that the Earth acts as a high-efficiency gravitational collector of low-velocity flow of dark matter (DM). The focal point appears on the Earth’s surface, when the DM flow speed is about 17 km/s with respect to the geo-center. We discuss diurnal modulation of the local DM density influenced by the Earth’s gravity. We also touch upon similar effects on galactic and solar system objects.

scholarly journals CFD Analysis of Contrarotating Open Rotor Aerodynamic Interactions

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Wenbo Shi ◽  
Jie Li ◽  
Zhao Yang ◽  
Heng Zhang
Keyword(s):  
Flow Field ◽  
Detailed Analysis ◽  
High Efficiency ◽  
Numerical Results ◽  
Operating Conditions ◽  
Power Coefficient ◽  
Complex Flow ◽  
Tip Vortices ◽  
Open Rotor ◽  
Blade Tip

High efficiency and low fuel consumption make the contrarotating open rotor (CROR) system a viable economic and environmentally friendly powerplant for future aircraft. While the potential benefits are well accepted, concerns still exist with respect to the vibrations and noise caused by the aerodynamic interactions of CROR systems. In this paper, emphasis is placed on the detailed analysis of the aerodynamic interactions between the front and aft propellers of a puller CROR configuration. For the first step, unsteady Reynolds-averaged Navier-Stokes (URANS) simulations coupled with dynamic patched grid technology are implemented on the isolated single-rotating propeller (SRP) configuration in various operating conditions in order to test the accuracy and feasibility of the numerical approach. The numerical results are verified by a wind tunnel test, showing good agreements with the experimental data. Subsequently, the URANS approach is applied to the CROR configuration. The numerical results obtained through the URANS approach help to improve the understanding of the complex flow field generated by the CROR configuration, and the comparison of SRP flow field and CROR flow field allows for a detailed analysis of the aerodynamic interactions of the front propeller blade wakes and tip vortices with the aft propeller. The main reason of the aerodynamic interactions is the mutual effects of the blade tip vortices, and the aft propeller reduces the strength of the blade tip vortices of the front propeller. Aerodynamic interactions will lead to the periodic oscillations of the aerodynamic forces, and the frequency of the oscillations is linked to the blade numbers. In addition, a CROR has a larger thrust and power coefficient than that of the SRP configuration in the same operating conditions. The URANS approach coupled with a dynamic patched grid method is tested to be an efficient and accurate tool in the analysis of propeller aerodynamic interactions.

Multi-fidelity optimization of blade thickness parameters for a horizontal axis tidal stream turbine

2019 ◽  
Vol 135 ◽  
pp. 277-287 ◽  
Author(s):  
P. Madhan Kumar ◽  
Jeonghwa Seo ◽  
Woochan Seok ◽  
Shin Hyung Rhee ◽  
Abdus Samad
Keyword(s):  
Horizontal Axis ◽  
Blade Thickness ◽  
Tidal Stream ◽  
Tidal Stream Turbine

Numerical Investigation of a Transonic Centrifugal Compressor

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
Michele Marconcini ◽  
Filippo Rubechini ◽  
Andrea Arnone ◽  
Seiichi Ibaraki
Keyword(s):  
Shock Waves ◽  
Flow Field ◽  
Centrifugal Compressor ◽  
Pressure Ratio ◽  
Turbulence Models ◽  
Tip Clearance ◽  
Complex Flow ◽  
Low Velocity ◽  
Flow Measurements ◽  
Vaned Diffuser

A three-dimensional Navier-Stokes solver is used to investigate the flow field of a high-pressure ratio centrifugal compressor for turbocharger applications. Such a compressor consists of a double-splitter impeller followed by a vaned diffuser. The inlet flow to the open shrouded impeller is transonic, thus giving rise to interactions between shock waves and boundary layers and between shock waves and tip leakage vortices. These interactions generate complex flow structures which are convected and distorted through the impeller blades. Detailed laser Doppler velocimetry flow measurements are available at various cross sections inside the impeller blades highlighting the presence of low-velocity flow regions near the shroud. Particular attention is focused on understanding the physical mechanisms which govern the flow phenomena in the near shroud region. To this end numerical investigations are performed using different tip clearance modelizations and various turbulence models, and their impact on the computed flow field is discussed.

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