News

23-04-2024. New publication: Secondary flows in the actuator-disk simulation of wind-turbine wakes, Navid Zehtabiyan-Rezaie, Ali Amarloo and Mahdi Abkar, Physics of Fluids, 2024.

22-03-2024. New publication: Grid convergence properties of wall-modeled large eddy simulations in the asymptotic regime, Xiang Yang, Mahdi Abkar and Goerge Park, Journal of Fluids Engineering, 2024.

23-01-2024. New publication: Flow investigation of two-stand ultrasonic flow meters in a wide dynamic range by numerical and experimental methods, Mario Javier Rincón, A. Caspersen, N.T. Ingwersen, Martino Reclari and Mahdi Abkar, Flow Mesearment and Instrumentation, 2024.

Schematic of a simplified two-stand ultrasonic flow meter with its main functioning components.

19-01-2024. New publication: Extension of the law of the wall exploiting weak similarity of velocity fluctuations in turbulent channels, Christoffer Hansen, Jens N. Sørensen, Xiang Yang and Mahdi Abkar, Physics of Fluids, 2024.

03-01-2024. New publication: An extended k−ɛ model for wake-flow simulation of wind farms, Navid Zehtabiyan-Rezaie and Mahdi Abkar, Renewable Energy, 2024.

29-12-2023. New publication: Progressive augmentation of turbulence models for flow separation by multi-case computational fluid dynamics driven surrogate optimisation, Ali Amarloo, Mario Javier Rincón, Martino Reclari and Mahdi Abkar, Physics of Fluids, 2023.

Optimization approach involving an initial sampling plan using Latin hypercube sampling, resolved through CFD.

21-12-2023. New publication: A priori screening of data-enabled turbulence models, Peng Chen, Yuanwei Bin, Xiang Yang, Yipeng Shi, Mahdi Abkar and George Park, Physical Review Fluids, 2023.

16-11-2023. New publication: A POD-mode-augmented wall model and its applications to flows at non-equilibrium conditions, Christoffer Hansen, Xiang Yang and Mahdi Abkar, Journal of Fluid Mechanics, 2023.

08-11-2023. New publication: Progressive augmentation of Reynolds stress tensor models for secondary flow prediction by computational fluid dynamics driven surrogate optimisation, Mario Javier Rincón, Ali Amarloo, Martino Reclari, Xiang Yang and Mahdi Abkar, International Journal of Heat and Fluid Flow, 2023.

20-10-2023. New publication: Reinforcement learning for wind-farm flow control: Current state and future actions, Mahdi Abkar, Navid Zehtabiyan-Rezaie and Alexandros Iosifidis, Theoretical and Applied Mechanics Letters, 2023.

Wind-farm-atmosphere interactions at different spatial scales: From airfoil scale to macro scale.

03-10-2023. Villum Synergy Grant: We have been awarded a grant from Villum Fonden (Villum Synergy: Applications in Data Driven Science) for a research project entitled: "Data-driven model discovery for turbulent flows". (PIs: Mahdi Abkar and Alexandros Iosifidis).

07-08-2023. We recently had an interview with Finans magazine and discussed the potential of AI in the wind industry, and how it can be leveraged to optimize power extraction from wind turbines when empirical models fall short. If you are interested, you can read more here: Der kan trækkes langt mere strøm ud af vindmøllerne med hjælp fra kunstig intelligens (finans.dk).

31-07-2023. New publication: Data-driven Reynolds stress models based on the frozen treatment of Reynolds stress tensor and Reynolds force vector, Ali Amarloo, Paola Cinnella, Alexandros Iosifidis, Pourya Forooghi and Mahdi Abkar, Physics of Fluids, 2023.

15-07-2023. New publication: A short note on turbulence characteristics in wind-turbine wakes, Navid Zehtabiyan-Rezaie and Mahdi Abkar, Journal of Wind Engineering & Industrial Aerodynamics, 2023.

05-07-2023. IFD Grant: We have been awarded a grant from Innovation Fund Denmark (IFD) for an industrial PhD project. The project is about "Techno-economic analysis of applying vacuum degassing to heating systems: Toward sustainable systems with reduced energy consumption and greenhouse gas emissions". (PI: Mahdi Abkar).

05-07-2023. IFD Grant: We have been awarded a grant from Innovation Fund Denmark (IFD) for an industrial Postdoc project. The project is about "Modeling of hydrogen jet impingement on structures for P2X technologies". (PI: Mahdi Abkar).

05-07-2023. IFD Grant: We have been awarded a grant from Innovation Fund Denmark (IFD) for an industrial Postdoc project. The project is about "Advanced design of ultrasonic flow meters through digitalisation: Leveraging the power of computational fluid dynamics and artificial intelligence". (PI: Mahdi Abkar).

07-06-2023. New publication: Survey of machine-learning wall models for large-eddy simulation, Aurélien Vadrot, Xiang Yang and Mahdi Abkar, Physical Review Fluids, 2023.

01-06-2023. New publication: RANS simulation of a wind turbine wake in the neutral atmospheric pressure-driven boundary layer, Mads Baungaard, M.Poul van der Laan, Stefan Wallin and Mahdi Abkar, Journal of Physics: Conference Series, 2023.

10-05-2023. New publication: Log-law recovery through reinforcement-learning wall model for large-eddy simulation, Aurélien Vadrot, Xiang Yang, H. Jane Bae and Mahdi Abkar, Physics of Fluids, 2023.

30-03-2023. New publication: Physics-guided machine learning for wind-farm power prediction: Toward interpretability and generalizability, Navid Zehtabiyan-Rezaie, Alexandros Iosifidis and Mahdi Abkar, PRX Energy, 2023.

27-02-2023. New publication: Data-driven dynamical system models of roughness-induced secondary flows in thermally stratified turbulent boundary layers, Christoffer Hansen, Xiang Yang and Mahdi Abkar, Journal of Fluids Engineering, 2023.

09-02-2023. New publication: Constructing neural network-based models for simulating dynamical systems, Christian Legaard, Thomas Schranz, Gerald Schweiger, Ján Drgoňa, Basak Falay, Cláudio Gomes, Alexandros Iosifidis, Mahdi Abkar and Peter Gorm Larsen, ACM Computing Survey, 2023.

A mind map of the topics and model types covered in the survey.

23-01-2023. New publication: Validating the design optimization of ultrasonic flow meters using computational fluid dynamics and surrogate modelling, Mario Javier Rincón, Martino Reclari, Xiang Yang and Mahdi Abkar, International Journal of Heat and Fluid Flow, 2023.

01-11-2022. New publication: Frozen propagation of Reynolds force vector from high-fidelity data into Reynolds-averaged simulations of secondary flows, Ali Amarloo, Pourya Forooghi and Mahdi Abkar, Physics of Fluids, 2022.

30-09-2022. New publication: Data-driven dynamical system models of roughness-induced secondary flows in thermally stratified turbulent boundary layers, Christoffer Hansen, Xiang Yang and Mahdi Abkar, ASME Fluids Engineering Conference, 2022.

06-08-2022. New publication: Turbulent flow in small-diameter ultrasonic flow meters: a numerical and experimental study, Mario Javier Rincón, Martino Reclari and Mahdi Abkar, Flow Mesearment and Instrumentation, 2022.

04-08-2022. New publication: Data-driven quantification of model-form uncertainty in Reynolds-averaged simulations of wind farms, Ali Eidi, Navid Zehtabiyan-Rezaie, Reza Ghiassi, Xiang Yang and Mahdi Abkar, Physics of Fluids, 2022.

19-07-2022. AIP Publishing highlighted our recent publication on "Data-driven fluid mechanics of wind farms: A review" with a Scilight article!

08-07-2022. New publication: Large-eddy simulation study of wind turbine array above swell sea, Haoze Yang, Mingwei Ge, Mahdi Abkar and Xiang Yang, Energy, 2022.

02-06-2022. New publication: A numerical investigation of a wind turbine wake in non-neutral atmospheric conditions, Mads Baungaard, Mahdi Abkar, M.Poul van der Laan and Mark Kelly, Journal of Physics: Conference Series, 2022.

27-05-2022. Ali Amarloo successfully defended his PhD qualifying exam. Congratulations!

29-04-2022. Mario Javier Rincón successfully defended his PhD qualifying exam. Congratulations!

25-04-2022. New publication: Data-driven fluid mechanics of wind farms: A review, Navid Zehtabiyan-Rezaie, Alexandros Iosifidis and Mahdi Abkar, Journal of Renewable and Sustainable Energy, 2022.

This paper has been chosen as a Featured Article by the journal's Editors.

21-03-2022. Stanford CTR Summer Program Visiting Researcher Award. The project is entitled: "Wall-model integrated large-eddy simulations using physics-constrained machine learning". (PIs: Mahdi Abkar, Xiang Yang).

29-01-2022. New publication: Logarithmic-linear law of the streamwise velocity variance in stably stratified boundary layers, Xiang I. A. Yang, Peng E. S. Chen, Ruifeng Hu and Mahdi Abkar, Boundary-Layer Meteorology, 2022.

17-01-2022. New publication: Secondary flows in statistically unstable turbulent boundary layers with spanwise heterogeneous roughness, Ali Amarloo, Pourya Forooghi and Mahdi Abkar, Theoretical and Applied Mechanics Letter, 2022.

12-11-2021. DFF: Sapere Aude - Research Leader Grant: We have been awarded a grant from Independent Research Fund Denmark (DFF) for a research project entitled: "Physics-constrained learning for turbulent flows". (PI: Mahdi Abkar).

05-10-2021. DFF: Green Transition Grant: We have been awarded a grant from Independent Research Fund Denmark (DFF) for a research project on the green transition. The project is entitled: "Drag reduction strategies for upgrading energy efficiency in Danish utility and maritime sectors". (PIs: Mahdi Abkar, Pourya Forooghi).

27-08-2021. New publication: Determining a priori a RANS model's applicable range via global epistemic uncertainty quantification, Xinyi Huang, Naman Jain, Mahdi Abkar, Robert Kunz and Xiang Yang, Computers & Fluids, 2021.

07-08-2021. New publication: Model-form uncertainty quantification in RANS simulations of wakes and power losses in wind farms, Ali Eidi, Reza Ghiassi, Xiang Yang and Mahdi Abkar, Renewable Energy, 2021.

15-03-2021. New publication: Wake steering of multirotor wind turbines, Gustav A. Speakman, Mahdi Abkar, Luis A. Martínez-Tossas and Majid Bastankhah, Wind Energy, 2021.

04-11-2020. New publication: Quantifying structural uncertainties in Reynolds-averaged Navier–Stokes simulations of wind turbine wakes, Simon D. Hornshøj-Møller, Peter D. Nielsen, Pourya Forooghi and Mahdi Abkar, Renewable Energy, 2021.

Normalized velocity deficit (top) and turbulence intensity (bottom), averaged over the rotor area, with downstream distance for the baseline RANS, LES and perturbed RANS simulations.

29-10-2020. DFF: Green Transition Grant: We have been awarded a grant from Independent Research Fund Denmark (DFF) for a research project on the green transition. The project is entitled: "Physics-informed deep learning for wind farm flow modeling". (PI: Mahdi Abkar).

19-10-2020. New publication: Roughness-induced secondary flows in stably stratified turbulent boundary layers, Pourya Forooghi, Xiang Yang and Mahdi Abkar, Physics of Fluids, 2020.

Lumley’s invariant map based on horizontally averaged Reynolds stresses. (a) Neutrally Stratified Case and (b) Stably Stratified Case .

21-09-2020. New publication: Energy harvesting via co-locating horizontal- and vertical-axis wind turbines, Michael Hansen, Peter Enevoldsen and Mahdi Abkar, Journal of Physics: Conference Series, 2020.

15-05-2020. Invited Guest Editor for the Special Issue on Recent Advances in Wind Farm Modelling, Optimization, Loads and Control in Energies.

27-03-2020. IFD Grant: We have been awarded a grant from Innovation Fund Denmark (IFD) for an industrial PhD project. The project is about "Robust optimization of flow meters using computational fluid dynamics with quantified uncertainty". (PI: Mahdi Abkar).

08-01-2020. New publication: Scaling of velocity fluctuations in statistically unstable boundary-layer flows, Xiang I. A. Yang, Sergio Pirozzoli and Mahdi Abkar, Journal of Fluid Mechanics, 2020.

Instantaneous streamwise velocity contour on spanwise/wall-normal plane. The velocity is normalized using the friction velocity.

28-08-2019. New publication: Wind turbine wakes in directionally varying wind shears, Mahdi Abkar, Fernando Porté-Agel and Jens N. Sørensen, Progress in Turbulence VIII, 2019.

06-08-2019. New publication: Multirotor wind turbine wakes, Majid Bastankhah and Mahdi Abkar, Physics of Fluids, 2019.

Schematic figure of (a) a single-rotor (SR) wind turbine and (b) a multi-rotor (MR) wind turbine.

22-07-2019. New publication: Improved energy production of multi-rotor wind farms, M. Paul van der Laan and Mahdi Abkar, Journal of Physics: Conference Series, 2019.

18-06-2019. New publication: Reynolds stress perturbation for epistemic uncertainty quantification of RANS models implemented in OpenFOAM, Luis F. Cremades Rey, Denis F. Hinz and Mahdi Abkar, Fluids, 2019.

Mean streamwise velocity field (top). Locations of points 1,2,3 in the barycentric map (bottom). These points are perturbed towards the three limiting states.

05-02-2019. New publication: Comparison of analysis methods for wind-driven cross ventilation through large opening, Khem R. Gautam, Li Rong, Guoqiang Zhang and Mahdi Abkar. Building and Environment, 2019.

21-12-2018. New publication: Theoretical modeling of vertical-axis wind turbine wakes, Mahdi Abkar, Energies, 2019.

Normalized velocity defect profiles, in wall-normal (left) and spanwise (right) directions, through the turbine center downstream. LES data (open circle), top-hat model (solid red line), and Gaussian model (solid black line). The horizontal dotted lines denote the turbine extent.

13-07-2018. New publication: An analytical model for the effect of vertical wind veer on wind turbine wakes, Mahdi Abkar, Jens N. Sørensen and Fernando Porté-Agel, Energies, 2018.

This article was selected as the featured paper in this edition of the journal.

Two-dimensional field of the normalized velocity deficit in the y-z planes at x/D=3, 5, 7, and 10 downstream of the turbine obtained from the LES. The location of the turbine is marked with the white circle.

10-07-2018. New publication: Impact of subgrid-scale modeling in actuator-line based large-eddy simulation of vertical-axis wind turbine wakes, Mahdi Abkar, Atmosphere, 2018.

Contours of the normalized instantaneous streamwise velocity in the central horizontal plane (top) and in the central vertical plane (bottom).

09-03-2018. New publication: A hierarchical random additive model for passive scalars in wall-bounded flows at high Reynolds numbers, Xiang I. A. Yang and Mahdi Abkar, Journal of Fluid Mechanics, 2018.

Left: a schematic of the modeled boundary layer. The attached eddies are space filling. On a vertical plane cut as shown here, the number of eddies doubles as the size halves. An eddy affects the shaded region below it. The velocity at a generic point in the flow field is a result of the additive superposition of all the eddy-induced velocity fields there. Right: the variance of the scalar fluctuation, velocity fluctuation and velocity-scalar correlation as functions of wall-normal distance in a boundary layer flow.

08-08-2017. New publication: Large-eddy simulation of thermally stratified atmospheric boundary-layer flow using a minimum dissipation model, Mahdi Abkar and Parviz Moin, Boundary-Layer Meteorology, 2017.

Vertical profiles of mean wind speed (left) and potential temperature (right) in the stable boundary layer using the AMD model with different spatial resolutions.

06-07-2017. Our paper published in Physics of Fluids has been selected by AIP Publishing as one of the most cited articles published in 2015: Influence of atmospheric stability on wind-turbine wakes: A large-eddy simulation study, Mahdi Abkar and Fernando Porte-Agel, Physics of Fluids, 2015.

Revised 24.04.2024

Mahdi Abkar