Searched for: subject:"piv"
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van Gent, P.L. (author)
Pressure reconstruction based on particle image velocimetry (PIV) refers to the determination of pressure data from pictures of small tracer particles added to a flow. The technique possesses a unique combination of beneficial characteristics in that it non-intrusively provides simultaneous pressure and velocity data in the flow field without...
doctoral thesis 2018
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Haidari, A.H. (author), Heijman, S.G.J. (author), van der Meer, W.G.J. (author)
Making improvements to feed spacers of spiral-wound membrane (SWM) modules of reverse osmosis (RO) is a necessary step towards a wider application of these modules. This study sets out to evaluate the performance of six commercial feed spacers by comparing their actual velocity profiles and their pressure drop. Velocity profiles are obtained...
journal article 2018
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Caridi, Giuseppe Carlo Alp (author)
A new type of tracer is making its entry in the scenario of wind-tunnel measurements: helium-filled soap bubbles (HFSB). The present work discusses the main fluid-dynamic and optical properties of HFSB to evaluate their use for quantitative measurements in aerodynamic experiments.
In the past three decades, particle image velocimetry (PIV)...
doctoral thesis 2018
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van Gent, P.L. (author), van Oudheusden, B.W. (author), Schrijer, F.F.J. (author)
The feasibility of computing the flow pressure on the basis of PIV velocity data has been demonstrated abundantly for low-speed conditions. The added complications occurring for high-speed compressible flows have, however, so far proved to be largely inhibitive for the accurate experimental determination of instantaneous pressure. Obtaining...
journal article 2018
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Guariglia, Daniel (author), Rubio Carpio, A. (author), Schram, Christophe (author)
Shock-cell noise occurs in aero-engines when the nozzle exhaust is supersonic and shock-cells are present in the jet. In commercial turbofan engines, at cruise, the secondary flow is often supersonic underexpanded, with the formation of annular shock-cells in the jet and consequent onset of shock-cell noise. This paper aims at describing the...
journal article 2018
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Sciacchitano, A. (author), Pattnaik, Pallav (author)
The flow field in the near wake of a 1:5.5 bobsleigh model was investigated by means of stereoscopic particle image velocimetry. The time-averaged flow field revealed two counter-rotating vortices and a strong downwash between them. From the velocity field, the aerodynamic drag was retrieved invoking the conservation of momentum. This approach...
conference paper 2018
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Engler Faleiros, D. (author), Tuinstra, Marthijn (author), Sciacchitano, A. (author), Scarano, F. (author)
The operating regimes of an orifice-type helium-filled soap bubbles (HFSB) generator are investigated to characterize the properties of the resulting tracers. The geometrical properties of the bubbles as well as the production rate are studied with high-speed shadowgraphy. The weight of the tracers relative to the mass of displaced air is...
conference paper 2018
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Scharnowski, Sven (author), Sciacchitano, A. (author), Kähler, Christian J. (author)
For the reliable estimation of velocity vector field s by means of 2D and 3D particle image velocimetry (PIV), the cross-correlation functions calculated from the signal within each interrogation window must feature a distinct peak that represents the average shift of the particle image ensemble. A high valid detection probability (VDP) of the...
conference paper 2018
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Spoelstra, A.M.C.M.G. (author), de Martino Norante, Luigi (author), Terra, W. (author), Sciacchitano, A. (author), Scarano, F. (author)
A procedure is proposed to reconstruct the instantaneous velocity field from full particle trajectories in a data assimilation framework that includes the vorticity transport equation. The technique is christened as time-segment assimilation (TSA). The work addresses the common problem of low seeding concentration in 3D experiments, usuallThe...
conference paper 2018
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Sciacchitano, A. (author), Terra, W. (author), Shah, Yash (author)
Large-scale Particle Tracking Velocimetry (PTV) measurements are cond ucted in the wake of a fu ll-scale cyclist model in time-trial position at freestream velocities between 12.5 and 15 m/ s, corresponding to Reynolds numbers of the order of 5×105. Lagrangian particle tracking is employed to determine the velocity and static pressure statistics...
conference paper 2018
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Terra, W. (author), Sciacchitano, A. (author), Scarano, F. (author), van Oudheusden, B.W. (author)
The accuracy of the “PIV wake rake” method to measure the drag of transiting objects is evaluated. Tomographic Particle Image Velocimetry measurements are conducted on a sphere towed at different speeds, within a Reynolds number range where the drag coefficient is constant. In contrast to PIV wake rake application on steady models in wind...
conference paper 2018
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Schneiders, J.F.G. (author), Scarano, F. (author)
A procedure is proposed to reconstruct the instantaneous velocity field from full particle trajectories in a data assimilation framework that includes the vorticity transport equation. The technique is christened as time-segment assimilation (TSA). The work addresses the common problem of low seeding concentration in 3D experiments, usually...
conference paper 2018
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Schneiders, J.F.G. (author)
A series of techniques is proposed for volumetric air flow measurements that are based upon the principles of particle image velocimetry (PIV). The proposed techniques fall in two categories; part 1 of this dissertation considers measurement data processing using constitutive laws and part 2 focuses on development of a coaxial volumetric flow...
doctoral thesis 2017
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Wieneke, B.F.A. (author)
The fundamental properties of computed flow fields using particle imaging velocimetry (PIV) have been investigated, viewing PIV processing as a black box without going in detail into algorithmic details. PIV processing can be analyzed using a linear filter model, i.e. assuming that the computed displacement field is the result of some spatial...
doctoral thesis 2017
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Scheuermann, A. (author), Harshani, H.M.D. (author), Galindo-Torres, S. (author), Aminpour, M. (author), Bittner, T. (author), Li, L. (author)
conference paper 2017
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Tollenaar Gonzalez, R.N. (author)
Waterways and lakes in low-lying delta areas require regular dredging for maintenance. Reuse of dredged sediments has been proposed for various applications. However, directly after dredging the physical characteristics of these sediments make them generally unsuited for immediate reuse. They are often placed on land, where they are allowed to...
doctoral thesis 2017
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Zhang, Y. (author)
Wind turbines are operating under very complex and uncontrolled environmental conditions, including atmospheric turbulence, atmospheric boundary layer effects, directional and spatial variations in wind shear, etc. Over the past decades, the size of a commercial wind turbine has increased considerably. All the complex and uncontrolled conditions...
doctoral thesis 2017
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Zhang, Xueqing (author), Sciacchitano, A. (author), Pröbsting, S. (author)
The present study investigates the feasibility of high-lift devices noise prediction based on measurements of time-resolved particle image velocimetry (TR-PIV). The model under investigation is a NACA 0015 airfoil with Gurney flap with height of 6% chord length. The velocity fields around and downstream the Gurney flap are measured by PIV and...
conference paper 2016
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Rui, Rui (author), van Tol, A.F. (author), Xia, YY (author), van Eekelen, SJM (author), Hu, G (author)
A trapdoor system has frequently been used to study soil arching and its development in recent years. The load transfer in the fill of piled embankments is very similar to a trapdoor system with multiple trapdoors. There are multiple arching models described in different standards and guidelines for piled embankments that can be subdivided into...
journal article 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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