Témakiírások
Optimization of urban rooftop vertical axis wind tunnel arrays through numerical simulations and reduced order modelling
témakiírás címe
Optimization of urban rooftop vertical axis wind tunnel arrays through numerical simulations and reduced order modelling
doktori iskola
témakiíró
tudományág
témakiírás leírása
a.) Preliminaries:
Recent studies highlight the growing focus on optimizing rooftop-mounted vertical axis wind turbines (VAWTs) for urban environments, where turbulent and complex wind conditions strongly affect performance. Experimental and computational research have already been carried out on aerodynamic behavior, placement effects, and flow interactions around buildings, influencing the performance of VAWTs. These works collectively demonstrate how factors such as building height, rooftop geometry, tip-speed ratio, and turbulence intensity influence energy capture. Researchers have also developed validated computational fluid dynamics (CFD) models and parametric frameworks to predict turbine efficiency under realistic urban inflows, emphasizing computational efficiency and design optimization. More recent efforts shift from isolated turbine analyses to integrated approaches that combine CFD with reduced-order modeling (ROM). Despite these advances, few studies have examined VAWT arrays on rooftops, highlighting the need for systematic, terrain-specific optimization frameworks for urban wind energy deployment.
VAWTs have already been investigated at our department through both measurements and numerical simulations. The supervisor have extended experience with research on turbomachinery operating at low-speed which is also characteristic of VAWTs.
b.) Aim of research:
The first aim of the research is to characterize rooftop wind behavior in urban environments through CFD simulations on representative building geometries, deriving detailed turbulence parameters relevant for VAWT performance assessment. Next, the aerodynamic efficiency of multiple rooftop-mounted VAWTs using Reynolds-Averaged Navier–Stokes (RANS) modeling is examined. Based on these results, a ROM is developed and trained on CFD data to efficiently predict and optimize power generation. The ROM is then coupled with optimization algorithms to identify the most effective configurations for rooftop turbine arrays. These optimal layouts are subsequently verified through additional high-fidelity CFD analyses, such as Large Eddy Simulation (LES), to ensure accuracy and robustness. Finally, the research produces comprehensive design recommendations for arranging rooftop VAWT arrays suited to typical urban wind conditions. The numerical results will be validated through already available literature data, and wind tunnel measurements in the laboratory of our department.
c.) Tasks, main items, necessary time:
Year 1:
• Literature review
• CFD domain setup
• Rooftop terrain modeling, establishing turbulence parameters for VAWTs simulations
Year 2:
• Design of Experiment: define design variables, selection of layouts for simulation
• CFD RANS simulations of array layouts, build performance database
• Preparation of wind tunnel measurements
• Publication on preliminary results
Year 3:
• Development of ROM models
• Implementation of optimization algorithms, find optimal layouts
• Wind tunnel measurements
• Publication on the result of optimization
Year 4:
• Validate optimal layouts via high-fidelity CFD analysis
• Dissertation writing, publication
d.) Required equipment:
The instruments needed to perform the measurements are available at the Department of Fluid Dynamics. The computing capacity for numerical simulations is partly available at the Department of Fluid Dynamics. HPC will be involved if necessary.
e.) Expected scientific results:
1. CFD database of rooftop VAWT array aerodynamics for different roof types.
2. A validated surrogate (ROM) model predicting VAWT array performance.
3. An optimization framework that can design efficient rooftop VAWT layouts quickly.
5. Practical design guidelines for urban planners and building engineers.
f.) References:
[1] Kovács, K. A., & Balla, E. (2025). Quantitative comparison of vortex identification methods in three-dimensional fluid flow around bluff bodies. INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW, 113. http://doi.org/10.1016/j.ijheatfluidflow.2025.109773
[2] Balla, E., & Vad, J. (2022). Models for Estimation of Lift and Drag Coefficients for Low-Reynolds-Number Cambered Plates. AIAA JOURNAL, 60(12), 6620–6632. http://doi.org/10.2514/1.J061579
[3] Balla, E., & Vad, J. (2021). An empirical model to determine lift and drag coefficients of cambered plates at moderate Reynolds numbers. PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART A-JOURNAL OF POWER AND ENERGY, 235(2), 202–210. http://doi.org/10.1177/0957650920915317
[4] Balla, E., & Vad, J. (2019). Lift and drag force measurements on basic models of low-speed axial fan blade sections. PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART A-JOURNAL OF POWER AND ENERGY, 233(2), 165–175. http://doi.org/10.1177/0957650918781906
Recent studies highlight the growing focus on optimizing rooftop-mounted vertical axis wind turbines (VAWTs) for urban environments, where turbulent and complex wind conditions strongly affect performance. Experimental and computational research have already been carried out on aerodynamic behavior, placement effects, and flow interactions around buildings, influencing the performance of VAWTs. These works collectively demonstrate how factors such as building height, rooftop geometry, tip-speed ratio, and turbulence intensity influence energy capture. Researchers have also developed validated computational fluid dynamics (CFD) models and parametric frameworks to predict turbine efficiency under realistic urban inflows, emphasizing computational efficiency and design optimization. More recent efforts shift from isolated turbine analyses to integrated approaches that combine CFD with reduced-order modeling (ROM). Despite these advances, few studies have examined VAWT arrays on rooftops, highlighting the need for systematic, terrain-specific optimization frameworks for urban wind energy deployment.
VAWTs have already been investigated at our department through both measurements and numerical simulations. The supervisor have extended experience with research on turbomachinery operating at low-speed which is also characteristic of VAWTs.
b.) Aim of research:
The first aim of the research is to characterize rooftop wind behavior in urban environments through CFD simulations on representative building geometries, deriving detailed turbulence parameters relevant for VAWT performance assessment. Next, the aerodynamic efficiency of multiple rooftop-mounted VAWTs using Reynolds-Averaged Navier–Stokes (RANS) modeling is examined. Based on these results, a ROM is developed and trained on CFD data to efficiently predict and optimize power generation. The ROM is then coupled with optimization algorithms to identify the most effective configurations for rooftop turbine arrays. These optimal layouts are subsequently verified through additional high-fidelity CFD analyses, such as Large Eddy Simulation (LES), to ensure accuracy and robustness. Finally, the research produces comprehensive design recommendations for arranging rooftop VAWT arrays suited to typical urban wind conditions. The numerical results will be validated through already available literature data, and wind tunnel measurements in the laboratory of our department.
c.) Tasks, main items, necessary time:
Year 1:
• Literature review
• CFD domain setup
• Rooftop terrain modeling, establishing turbulence parameters for VAWTs simulations
Year 2:
• Design of Experiment: define design variables, selection of layouts for simulation
• CFD RANS simulations of array layouts, build performance database
• Preparation of wind tunnel measurements
• Publication on preliminary results
Year 3:
• Development of ROM models
• Implementation of optimization algorithms, find optimal layouts
• Wind tunnel measurements
• Publication on the result of optimization
Year 4:
• Validate optimal layouts via high-fidelity CFD analysis
• Dissertation writing, publication
d.) Required equipment:
The instruments needed to perform the measurements are available at the Department of Fluid Dynamics. The computing capacity for numerical simulations is partly available at the Department of Fluid Dynamics. HPC will be involved if necessary.
e.) Expected scientific results:
1. CFD database of rooftop VAWT array aerodynamics for different roof types.
2. A validated surrogate (ROM) model predicting VAWT array performance.
3. An optimization framework that can design efficient rooftop VAWT layouts quickly.
5. Practical design guidelines for urban planners and building engineers.
f.) References:
[1] Kovács, K. A., & Balla, E. (2025). Quantitative comparison of vortex identification methods in three-dimensional fluid flow around bluff bodies. INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW, 113. http://doi.org/10.1016/j.ijheatfluidflow.2025.109773
[2] Balla, E., & Vad, J. (2022). Models for Estimation of Lift and Drag Coefficients for Low-Reynolds-Number Cambered Plates. AIAA JOURNAL, 60(12), 6620–6632. http://doi.org/10.2514/1.J061579
[3] Balla, E., & Vad, J. (2021). An empirical model to determine lift and drag coefficients of cambered plates at moderate Reynolds numbers. PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART A-JOURNAL OF POWER AND ENERGY, 235(2), 202–210. http://doi.org/10.1177/0957650920915317
[4] Balla, E., & Vad, J. (2019). Lift and drag force measurements on basic models of low-speed axial fan blade sections. PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART A-JOURNAL OF POWER AND ENERGY, 233(2), 165–175. http://doi.org/10.1177/0957650918781906
felvehető hallgatók száma
1 fő
jelentkezési határidő
2026-04-30