Publications by Mahdi Abkar | EPFL Graph Search

Related publications (13)

Mean and turbulent kinetic energy budgets inside and above very large wind farms under conventionally-neutral condition

In this study, large-eddy simulations (LES) is combined with a turbine model to investigate all the terms in the budgets of mean and turbulent kinetic energy (TKE) inside and above very large wind farms. Emphasis is placed on quantifying the relative contr ...

Pergamon-Elsevier Science Ltd2014

Wake flow in a wind farm during a diurnal cycle

Fernando Porté Agel, Mahdi Abkar, Ahmad Sharifi

The atmospheric boundary layer (ABL) undergoes substantial changes in its structure and dynamics in the course of a day due to the transient nature of forcing factors such as the surface fluxes of heat and momentum. The non-stationary nature of the mean wi ...

Taylor & Francis2016

The Effect of Free-Atmosphere Stratification on Boundary-Layer Flow and Power Output from Very Large Wind Farms

Fernando Porté Agel, Mahdi Abkar

Large-eddy simulation is used to study the influence of free-atmosphere stratification on the structure of atmospheric boundary-layer flow inside and above very large wind farms, as well as the power extracted by the wind turbines. In the simulations, tuni ...

Mdpi Ag2013

Large-eddy simulation of the diurnal variation of wake flows in a finite-size wind farm

Fernando Porté Agel, Mahdi Abkar, Ahmad Sharifi

In this study, large-eddy simulation (LES) is used to study the evolution of the wind-turbine wakes and their effects on power losses inside an idealized finite-size wind farm in the course of a full diurnal cycle. In the LES, turbulent subgrid-scale stres ...

Iop Publishing Ltd2015

Data-driven Reduced Order Model for prediction of wind turbine wakes

Fernando Porté Agel, Giacomo Valerio Iungo, Mahdi Abkar

In this paper a new paradigm for prediction of wind turbine wakes is proposed, which is based on a reduced order model (ROM) embedded in a Kalman filter. The ROM is evaluated by means of dynamic mode decomposition performed on high fidelity LES numerical s ...

Iop Publishing Ltd2015

Influence of the Coriolis force on the structure and evolution of wind turbine wakes

Fernando Porté Agel, Mahdi Abkar

In this study, large-eddy simulation combined with a turbine model is used to investigate the effect of vertical wind veer associated with the Coriolis force on the structure and evolution of wind turbine wakes. In order to isolate the Coriolis effect on t ...

Amer Physical Soc2016

Wind Turbine Wakes in Directionally Varying Wind Shears

Fernando Porté Agel, Mahdi Abkar

In the atmospheric boundary layer, the Coriolis force associated with the Earth’s rotation induces a spanwise wind shear in addition to the wall-normal one leading to a continuous change in wind direction with height. The spanwise wind shear in directional ...

2019

Influence of atmospheric stability on wind-turbine wakes: A large-eddy simulation study

Fernando Porté Agel, Mahdi Abkar

In this study, large-eddy simulation is combined with a turbine model to investigate the influence of atmospheric thermal stability on wind-turbine wakes. The simulation results show that atmospheric stability has a significant effect on the spatial distri ...

American Institute of Physics2015

A new boundary condition for large-eddy simulation of boundary-layer flow over surface roughness transitions

Fernando Porté Agel, Mahdi Abkar

Large-eddy simulations are performed to evaluate the performance of the surface boundary condition downwind of a rough-to-smooth surface transition. Two types of boundary conditions are tested: (1) The standard formulation based on local application of the ...

Taylor & Francis2012

The effect of atmospheric stability on wind-turbine wakes: A large-eddy simulation study

Fernando Porté Agel, Mahdi Abkar

In this study, large-eddy simulation is used to investigate the influence of atmospheric stability on wind-turbine wakes. In the simulations, tuning-free Lagrangian scale-dependent dynamic models are used to model the subgrid-scale turbulent fluxes, while ...

IOP Publishing Ltd2014

A new wind-farm parameterization for large-scale atmospheric models

Fernando Porté Agel, Mahdi Abkar

In this article, a new model is developed to parameterize the effect of wind farms in large-scale atmospheric models such as weather models. In the new model, wind turbines in a wind farm are parameterized as elevated sinks of momentum and sources of turbu ...

Amer Inst Physics2015

Interaction of the atmospheric boundary layer with land surface heterogeneity and wind turbines : numerical and analytical studies

Mahdi Abkar

EPFL2014

An Analytical Model for the Effect of Vertical Wind Veer on Wind Turbine Wakes

Fernando Porté Agel, Mahdi Abkar

2018