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- van Rooij, A.C.L.M. (author), Nitzsche, J. (author), Dwight, R.P. (author) conference paper 2017
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- van Rooij, A.C.L.M. (author), Nitzsche, J. (author), Dwight, R.P. (author) journal article 2017
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Azijli, I. (author), Sciacchitano, A. (author), Ragni, D. (author), Palha, A. (author), Dwight, R.P. (author)A methodology for a posteriori uncertainty quantification of pressure data retrieved from particle image velocimetry (PIV) is proposed. It relies upon the Bayesian framework, where the posterior distribution (probability distribution of the true velocity, given the PIV measurements) is obtained from the prior distribution (prior knowledge of...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
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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
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van den Bos, L.M.M. (author), Koren, B (author), Dwight, R.P. (author)The problem of non-intrusive uncertainty quantification is studied, with a focus on two computational fluid dynamics cases. A collocation method using quadrature or cubature rules is applied, where the simulations are selected deterministically. A one-dimensional quadrature rule is proposed which is nested, symmetric, and has positive weights....conference paper 2016
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Ubbens, H.H. (author), Dwight, R.P. (author), Sciacchitano, A. (author), Timmer, W.A. (author)Bobsleighs races nowadays are decided upon hundredths of a second. As the margins are that small the aerodynamics of a bobsleigh can play a significant role in a race outcome. This paper investigates the influence of the gap between the nose and the rear cowling of a two-man bobsleigh. The paper especially focusses on the misalignment between...journal article 2016
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Schneiders, J.F.G. (author), Azijli, I. (author), Scarano, F. (author), Dwight, R.P. (author)A method is proposed to reconstruct instantaneous velocity from time-resolved tomographic PTV, employing both instantaneous velocity and velocity material derivative. This improves upon current techniques by not only including penalization of velocity divergence, but also requiring consistency with the temporal derivative of the PTV particle...conference paper 2015
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de Baar, J.H.S. (author), Roberts, S (author), Dwight, R.P. (author), Mallol, B. (author)Uncertainty Quantication (UQ) for CFD-based ship design can require a large number of simulations, resulting in signicant overall computational cost. Presently, we use an existing method, multi-delity Kriging, to reduce the number of simulations required for the UQ analysis of the performance of a sailing yacht hull, considering uncertainties in...journal article 2015
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Azijli, I. (author), Dwight, R.P. (author)Volumetric velocity measurements of incompressible flows contain spurious divergence due to measurement noise, despite mass conservation dictating that the velocity field must be divergence-free (solenoidal). We investigate the use of Gaussian process regression to filter spurious divergence, returning analytically solenoidal velocity fields. We...journal article 2015
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Azijli, I. (author), Sciacchitano, A. (author), Ragni, D. (author), Palha da Silva Clerigo, A. (author), Dwight, R.P. (author)The present work proposes a methodology for the a posteriori quantification of the uncertainty of pressure data retrieved from PIV measurements. It relies upon the Bayesian framework, where the posterior distribution (probability distribution of the true velocity, given the PIV measurements) is obtained from the prior distribution (prior...conference paper 2015
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Percin, M. (author), De Baar, J.H.S. (author), Van Oudheusden, B.W. (author), Dwight, R.P. (author)The work explores the three-dimensional unsteady wake of a flapping-wing Micro Air Vehicle (MAV) ‘DelFly II’, applying a Kriging regression technique for the spatial regression of time-resolved Stereoscopic Particle Image Velocimetry (Stereo-PIV) data. In the view of limited number of measurement planes, the particular objective of the...conference paper 2013
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Sciacchitano, A. (author), Dwight, R.P. (author), Scarano, F. (author)Velocity measurements conducted with particle image velocimetry (PIV) often exhibit regions where the flow motion cannot be evaluated. The principal reasons for this are the absence of seeding particles or limited optical access for illumination or imaging. Additional causes can be laser light reflections and unwanted out-of-focus effects. As a...conference paper 2012
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Boon, D.J. (author), Dwight, R.P. (author), Sterenborg, J.J.H.M. (author), Bijl, H. (author)We perform a fully stochastic analysis of an experiment in aerodynamics. Given estimated uncertainties on the principle input parameters of the experiment, including uncertainties on the shape of the model, we apply uncertainty propagation methods to a suitable CFD model of the experimental setup. Thereby we predict the stochastic response of...conference paper 2012
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Brezillon, J. (author), Dwight, R.P. (author)Within the next few years, numerical shape optimisation based on high-fidelity methods is likely to play a strategic role in future aircraft design. In this context, suitable tools have to be developed for solving aerodynamic shape optimisation problems, and the adjoint approach—which allows fast and accurate evaluations of the gradients with...journal article 2012
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De Baar, J.H.S. (author), Dwight, R.P. (author), Bijl, H. (author)We apply Ordinary Kriging to predict 75,000 terrain survey data from a randomly sampled subset of < 2500 observations. Since such a Kriging prediction requires a considerable amount of CPU time, we aim to reduce its computational cost. In a conventional approach, the cost of the Kriging analysis would be dominated by the optimization routine...conference paper 2011
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Dwight, R.P. (author)It has recently been observed that Least-Squares Finite Element methods (LS-FEMs) can be used to assimilate experimental data into approximations of PDEs in a natural way, as shown by Heyes et al. in the case of incompressible Navier Stokes ow [1]. The approach was shown to be effective without regularization terms, and can handle substantial...journal article 2010
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- Dwight, R. (author) journal article 2010
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Michler, A.K. (author), Dwight, R.P. (author), Heinrich, R. (author)The accurate prediction of the aerodynamic coefficients under cruise conditions is of major importance for assessing the aircraft’s fuel consumption. To this end, fluid dynamics, structural mechanics and flight mechanics have to be considered: on the one hand, the structure elastically deforms under the influence of the flow and a state of...conference paper 2009