Searched for: department:"Wind%5C+Energy"
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Terra, W. (author), Sciacchitano, A. (author), Scarano, F. (author)

A method is introduced to measure the aerodynamic drag of moving objects such as ground vehicles or athletes in speed sports. Experiments are conducted as proof-of-concept that yield the aerodynamic drag of a sphere towed through a square duct in stagnant air. The drag force is evaluated using large-scale tomographic PIV and invoking the time...

journal article 2017
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Schneiders, J.F.G. (author), Scarano, F. (author), Elsinga, G.E. (author)

The existing time-resolved tomographic particle image velocimetry (PIV) measurements by Jodai and Elsinga (J Fluid Mech 795:611–633; Jodai, Elsinga, J Fluid Mech 795:611–633, 2016) in a turbulent boundary layer (Reθ = 2038) are reprocessed using tomographic particle tracking velocimetry (PTV) and vortex-in-cell-plus (VIC+). The...

journal article 2017
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Lignarolo, L. (author), Ragni, D. (author), Simao Ferreira, C.J. (author), Van Bussel, G.J.W. (author)
The actuator disc (AD) model is commonly used to simplify the simulation of horizontal-axis wind-turbine aerodynamics. The limitations of this approach in reproducing the wake losses in wind farm simulations have been proven by a previous research. The present study is aimed at providing an experimental analysis of the near-wake turbulent flow...
journal article 2016
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Caridi, G. (author), Ragni, D. (author), Sciacchitano, A. (author), Scarano, F. (author)

A new system for large-scale tomographic particle image velocimetry in low-speed wind tunnels is presented. The system relies upon the use of sub-millimetre helium-filled soap bubbles as flow tracers, which scatter light with intensity several orders of magnitude higher than micron-sized droplets. With respect to a single bubble generator,...

journal article 2016
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Chen, Xiaoqian (author), Yao, W (author), Zhao, Yong (author), Ouyang, Qi (author)

The reliability analysis approach based on combined probability and evidence theory is studied in this paper to address the reliability analysis problem involving both aleatory uncertainties and epistemic uncertainties with flexible intervals (the interval bounds are either fixed or variable as functions of other independent variables). In...

journal article 2016
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Zaccai, D (author), Bertels, F.G.A. (author), Vos, R. (author)
A new methodology has been developed that integrates the preliminary wing design with trailing edge high-lift systems and accounts for three-dimensional flap kinematics. The high-lift system in the developed application includes the kinematic synthesis of four common mechanisms (dropped-hinge, four-bar, link-track and hooked-track) and a...
journal article 2016
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Ye, Q. (author), Schrijer, F.F.J. (author), Scarano, F. (author)
The transitional flow features over and downstream of isolated roughness elements in hypersonic flow are investigated by means of infrared thermography. The local heat flux distribution in the wake of the roughness element reveals the footprint of multiple streamwise counter-rotating vortex pairs. The formation of a turbulent wedge with the...
conference paper 2016
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Schneiders, J.F.G. (author), Pröbsting, S. (author), Dwight, R.P. (author), Van Oudheusden, B.W. (author), Scarano, F. (author)
A method is proposed to determine the instantaneous pressure field from a single tomographic PIV velocity snapshot and is applied to a flat-plate turbulent boundary layer. The main concept behind the single-snapshot pressure evaluation method is to approximate the flow acceleration using the vorticity transport equation. The vorticity field...
journal article 2016
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Schneiders, J.F.G. (author), Pröbsting, S. (author), Dwight, R.P. (author), Van Oudheusden, B.W. (author), Scarano, F. (author)
A method is proposed to determine the instantaneous pressure field from a single tomographic PIV velocity snapshot and is applied to a flat-plate turbulent boundary layer. The main concept behind the single-snapshot pressure evaluation method is to approximate the flow acceleration using the vorticity transport equation. The vorticity field...
journal article 2016
document
Schneiders, J.F.G. (author), Pröbsting, S. (author), Dwight, R.P. (author), Van Oudheusden, B.W. (author), Scarano, F. (author)
A method is proposed to determine the instantaneous pressure field from a single tomographic PIV velocity snapshot and is applied to a flat-plate turbulent boundary layer. The main concept behind the single-snapshot pressure evaluation method is to approximate the flow acceleration using the vorticity transport equation. The vorticity field...
journal article 2016
document
Ye, Q. (author), Schrijer, F.F.J. (author), Scarano, F. (author)
Boundary layer transition over isolated roughness elements is investigated in the incompressible flow regime using tomographic PIV. Four different geometries (cylinder, square, hemisphere and micro-ramp) are considered maintaining constant height and span of the element. The main target is to compare the different flow topologies and study the...
journal article 2016
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Arce León, C.A. (author), Ragni, D. (author), Pröbsting, S. (author), Scarano, F. (author), Madsen, Jesper (author)
The flow past a NACA 0018 airfoil with sawtooth trailing edge serrations has been investigated using stereoscopic particle image velocimetry (PIV). The serration flap angle and airfoil incidence are varied in order to study the effect of secondary flow establishing between the suction and pressure sides of the serrations. The flow topology...
journal article 2016
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Schneiders, J.F.G. (author), Scarano, F. (author)
A method is proposed to reconstruct the instantaneous velocity field from time-resolved volumetric particle tracking velocimetry (PTV, e.g., 3D-PTV, tomographic PTV and Shake-the-Box), employing both the instantaneous velocity and the velocity material derivative of the sparse tracer particles. The constraint to the measured temporal derivative...
journal article 2016
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Schneiders, J.F.G. (author), Caridi, G. (author), Sciacchitano, A. (author), Scarano, F. (author)
The instantaneous volumetric pressure in the near-wake of a truncated cylinder is measured by use of tomographic particle tracking velocimetry (PTV) using helium-filled soap bubbles (HFSB) as tracers. The measurement volume is several orders of magnitude larger than that reported in tomographic experiments dealing with pressure from particle...
journal article 2016
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Schneiders, J.F.G. (author), Scarano, F. (author), Elsinga, G.E. (author)
conference paper 2016
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Terra, W. (author), Sciacchitano, A. (author), Scarano, F. (author)

Aerodynamic drag is computed from velocity measurements obtained with particle image velocimetry (PIV). This allows determining the drag force in combination with the visualization of the flow structures responsible for drag generation. Two experiments are conducted to illustrate the working principle of the approach, which is meant for...

journal article 2016
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Gentile, V. (author), Schrijer, F.F.J. (author), van Oudheusden, B.W. (author), Scarano, F. (author)
The turbulent wake past an axisymmetric body is investigated with time-resolved stereoscopic particle image velocimetry (PIV) at a Reynolds number ReD = 6.7 × 104 based on the object diameter. The azimuthal organization of the near-wake is studied at different locations downstream of the trailing edge. The time-averaged velocity field features a...
journal article 2016
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Gentile, V. (author), Schrijer, F.F.J. (author), van Oudheusden, B.W. (author), Scarano, F. (author)
The backflow instability in the wake past a cylindrical blunt-based body in pitch is investigated at a Reynolds number ReD = 6.7 · 104 based on the cylinder diameter. Time-resolved stereoscopic particle image velocimetry measurements have been performed in a cross-flow plane located 0.3 D downstream of the model base. An increasing displacement...
conference paper 2016
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Gentile, V. (author), Schrijer, F.F.J. (author), van Oudheusden, B.W. (author), Scarano, F. (author)
The so-called very-low-frequency (VLF) azimuthal meandering of the reversed-flow region has been shown to contribute significantly to the unsteadiness of the turbulent wake flow past a bluff body of revolution (Rigas et al. 2014; Grandemange et al. 2014). Such an erratic behavior causes a continuous change in the wake topology and, particularly...
conference paper 2016
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Terra, W. (author), Sciacchitano, A. (author), Scarano, F. (author)
Experiments are conducted to determine the drag of a full-scale cyclist model in a wind tunnel at 4 m/s. The aerodynamic drag is evaluated from tomo-PIV measurements in the wake of the model applying the conservation of momentum within a control volume. The measurements are conducted in a thin volume of 100 x 170 x 3 cubic centimeters using...
conference paper 2016
Searched for: department:"Wind%5C+Energy"
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