Browsing by Author "Nishino, Takafumi"

Analysing momentum balance over a large wind farm using a numerical weather prediction model

Lun, Ma; Dunstan, Thomas D.; Nishino, Takafumi (IOP Publishing, 2020-09-21)

This study attempts to better understand the mechanisms of wind farm blockage effect by analysing momentum balance in realistic atmospheric flow over an idealised large offshore wind farm. The analysis is performed following ...

Blade-resolved CFD simulations of a periodic array of NREL 5 MW rotors with and without towers

Ma, Lun; Delafin, Pierre-Luc; Tsoutsanis, Panagiotis; Antoniadis, Antonis F.; Nishino, Takafumi (MDPI, 2022-01-14)

A fully resolved (FR) NREL 5 MW turbine model is employed in two unsteady Reynolds-averaged Navier–Stokes (URANS) simulations (one with and one without the turbine tower) of a periodic atmospheric boundary layer (ABL) to ...

CFD study of a bidirectional synthetic jet as an aerodynamic flow control device.

Fisher Fernandez, Jaime Rodrigo (2018-03)

Control of the separation and reattachment of the boundary layer has been the focus of research for a wide range of engineering applications, and it is known that a synthetic jet can be used as an active flow control device ...

Comparison of low-order aerodynamic models and RANS CFD for full scale 3D vertical axis wind turbines

Delafin, Pierre-Luc; Nishino, Takafumi; Athanasios, Kolios; Lin, Wang (Elsevier, 2017-03-21)

A Double Multiple Streamtube model, a free-wake vortex model (both widely used for vertical axis wind turbine design) and RANS CFD simulations are used in this work to predict the performance of the 17 m Vertical Axis Wind ...

Development of a stochastic computational fluid dynamics approach for offshore wind farms

Richmond, Mark; Kolios, Athanasios; Pillai, V. S.; Nishino, Takafumi; Wang, L. (IOP, 2018-06-19)

In this paper, a method for stochastic analysis of an offshore wind farm using computational fluid dynamics (CFD) is proposed. An existing offshore wind farm is modelled using a steady-state CFD solver at several deterministic ...

Effect of the number of blades and solidity on the performance of a vertical axis wind turbine

Delafin, Pierre-Luc; Nishino, Takafumi; Wang, Lin; Kolios, Athanasios (IOP Publishing: Conference Series / Institute of Physics (IoP), 2016-10-03)

Two, three and four bladed phgr-shape Vertical Axis Wind Turbines are simulated using a free-wake vortex model. Two versions of the three and four bladed turbines are considered, one having the same chord length as the ...

Energetic and exergetic study for cross-corrugated membrane-based total recovery exchanger for ventilation

Abduljabbar, Ahmed A. (2017-10)

Indoor air quality is an important component of the air conditioning of buildings due to its major effect on the health of the occupants, thus the air supplied to these buildings by the ventilation system should be sufficient, ...

Flow through a very porous obstacle in a shallow channel

Creed, M. J.; Draper, S.; Nishino, Takafumi; Borthwick, A. G. L. (The Royal Society, 2017-04-26)

A theoretical model, informed by numerical simulations based on the shallow water equations, is developed to predict the flow passing through and around a uniform porous obstacle in a shallow channel, where background ...

Fluid dynamic mechanisms of enhanced power generation by closely spaced vertical axis wind turbines

Zanforlin, Stefania; Nishino, Takafumi (Elsevier, 2016-08-18)

We present a comprehensive set of two-dimensional (2D) unsteady Reynolds-averaged Navier-Stokes (URANS) simulations of flow around a pair of counter-rotating vertical-axis wind turbines (VAWTs). The simulations are performed ...

Local blockage effect for wind turbines

Nishino, Takafumi; Draper, Scott (IOP Publishing, 2015-06-11)

This paper presents a combined theoretical and CFD study on the fluid-mechanical limit of power extraction by a closely-spaced lateral array of wind turbines. The idea of this study originates in recent studies on the array ...

Momentum balance in a fully developed boundary layer over a staggered array of NREL 5MW rotors

Delafin, Pierre-Luc; Nishino, Takafumi (IOP Publishing, 2017-06-13)

3D Reynolds-averaged Navier-Stokes (RANS) simulations of a fully developed wind farm boundary layer over a staggered array of NREL 5MW turbines are presented. The turbine is modeled as an actuator disk and as a fully ...

Numerical Analysis of a Bidirectional Synthetic Jet for Active Flow Control

Nishino, Takafumi; Savill, Mark A. (American Institute of Aeronautics and Astronautics, 2017-01-11)

Numerical study of airfoil stall cells using a very wide computational domain

Manni, Luca; Nishino, Takafumi; Delafin, Pierre-Luc (Elsevier, 2016-10-05)

The formation of stall cells over a NACA 0012 airfoil at a Reynolds number of one million has been investigated numerically, using unsteady Reynolds-averaged Navier–Stokes (URANS) and delayed detached-eddy simulation (DDES) ...

Numerical study on the limit of power extraction by a dense cross-stream array of wind turbines

Tartari, Filiberto; Nishino, Takafumi (Elsevier, 2017-06-27)

A numerical study is presented on the upper limit of power extraction by a dense cross-stream array of wind turbines, using 3D Reynolds-averaged Navier–Stokes simulations of flow over porous discs. The main objectives are: ...

Numerical validation of the two-scale actuator disc theory for marine turbine arrays

Perez-Campos, Edgar; Nishino, Takafumi (Unknown, 2015-09-11)

The challenge in the hydrodynamic modelling of tidal and marine turbine farms is to take into account the interaction of flow events across a wide range of scales, such as the blade scale, turbine scale, array scale and ...

Performance of an ideal turbine in an inviscid shear flow

Draper, S.; Nishino, Takafumi; Adcock, T. A. A.; Taylor, P. H. (Journal of Fluid Mechanics, 2016-04-28)

Although wind and tidal turbines operate in turbulent shear flow, most theoretical results concerning turbine performance, such as the well-known Betz limit, assume the upstream velocity profile is uniform. To improve on ...

Preliminary estimate of the impact of support structures on the aerodynamic performance of very large wind farms

Ma, Lun; Nishino, Takafumi (IOP, 2018-06-19)

An extended theoretical model, which is based on a two-scale coupled momentum conservation argument, is proposed to estimate aerodynamic effects of support structures on the performance of ideal very large wind farms. A ...

Structural optimisation of vertical-axis wind turbine composite blades based on finite element analysis and genetic algorithm

Wang, Lin; Kolios, Athanasios; Nishino, Takafumi; Delafin, Pierre-Luc; Bird, Theodore (Elsevier, 2016-06-02)

A wind turbine blade generally has complex structures including several layers of composite materials with shear webs, making its structure design very challenging. In this paper, a structural optimisation model for wind ...

Two-scale dynamics of flow past a partial cross-stream array of tidal turbines

Nishino, Takafumi; Willden, R. H. J. (Cambridge University Press, 2016-07-30)

The characteristics of flow past a partial cross-stream array of (idealized) tidal turbines are investigated both analytically and computationally to understand the mechanisms that determine the limiting performance of ...

Two-scale momentum theory for very large wind farms

Nishino, Takafumi (IOP Publishing: Conference Series / Institute of Physics (IoP), 2016-10-03)

A new theoretical approach is proposed to predict a practical upper limit to the efficiency of a very large wind farm. The new theory suggests that the efficiency of ideal turbines in an ideal very large wind farm depends ...

Browsing by Author "Nishino, Takafumi"

Browsing by Author "Nishino, Takafumi"

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