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de Hoop, Stephan (author)Under-sampling of the subsurface combined with scale differences in observations causes the estimation of geological parameters to be an ill-posed problem. As a result, only a subset of theoretically possible models can truly depict the reality. In reservoir modeling, we capture complexity and heterogeneity by representing the solution space...master thesis 2017
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Kotnik, Aljaž (author)In the framework of LuFo R\&T projects a number of Rolls-Royce Deutschland Low and High Pressure Compressor rotor blades were geometrically scanned at the beginning and end of their life cycle. Based on this data component wear, ageing and manufacturing variability across the life cycle of the engine can be derived. Using Computational Fluid...master thesis 2017
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Belligoli, Z. (author), Dwight, R.P. (author), Kok, G. J.P. (author), Lucas, P. (author)This paper presents an approach for updating the epistemic uncertainty of ultrasonic flow meter measurements under non-ideal flow conditions. Instead of re-calibrating the instrument to correct its behavior in these difficult working conditions, a Bayesian calibration of a computer model of the real process is used. The numerical model is...journal article 2017
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Sciacchitano, A. (author), Wieneke, Bernhard (author)This paper discusses the propagation of the instantaneous uncertainty of PIV measurements to statistical and instantaneous quantities of interest derived from the velocity field. The expression of the uncertainty of vorticity, velocity divergence, mean value and Reynolds stresses is derived. It is shown that the uncertainty of vorticity and...journal article 2016
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Dimitrova, I.D. (author)The natural frequency of wind turbine towers can be more than 10% off from the designed frequency. This frequency is important for control because it sets bandwidth limits to some of the control loops. Improving the model will result in better control and load reduction that will in turn contribute to the decrease of the cost of wind energy. The...master thesis 2016
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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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Scholcz, T.P. (author)The cost and turnaround time of the load calculation cycle in the design process of aircraft can be reduced by developing new numerical simulation technologies aimed at efficient prediction of steady and unsteady force coefficients in the flight envelope. In order to capture the most extreme stress levels due to gust and manoeuvres, efficient...doctoral thesis 2015
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Iyer, S.V. (author)In recent years, the scientific community has shown increased interest in the use of uncertainty quantification techniques for complex thermodynamic systems. One such complex system is the Organic Rankine Cycle (ORC) power system for which a turbine is often the prime mover. These systems operate in a region close to the critical conditions of...master thesis 2015
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Edeling, W.N. (author)The goal of this thesis is to make predictive simulations with Reynolds-Averaged Navier-Stokes (RANS) turbulence models, i.e. simulations with a systematic treatment of model and data uncertainties and their propagation through a computational model to produce predictions of quantities of interest with quantified uncertainty. To do so, we make...doctoral thesis 2015
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Perkó, Z. (author)This thesis presents novel adjoint and spectral methods for the sensitivity and uncertainty (S&U) analysis of multi-physics problems encountered in the field of reactor physics. The first part focuses on the steady state of reactors and extends the adjoint sensitivity analysis methods well established for pure neutron transport problems to...doctoral thesis 2015
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Sciacchitano, A. (author)Particle Image Velocimetry (PIV) is a well-established technique for the measurement of the flow velocity in a two or three-dimensional domain. As in any other technique, PIV data is affected by measurement errors, defined as the difference between the measured velocity and its actual value, which is unknown. Aim of uncertainty quantification is...doctoral thesis 2014
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- Javed, A. (author) doctoral thesis 2014
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Scheel, F. (author), De Boer, W.P. (author), Brinkman, R. (author), Luijendijk, A.P. (author), Ranasinghe, R.W.M.R.J.B. (author)A variety of uncertainty sources are inherent in process-based morphodynamic modelling applications. There is an increasing demand for the quantification of these uncertainties. This contribution introduces a probabilistic-morphodynamic (PM) modelling framework that enables this quantification. The PM modelling framework provides a systematic...conference paper 2014
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Ensing, J.J. (author)Upstream oil companies in the Middle East are more frequently confronted with decisions on continuing the oil production of mature oil fields. The low production rates of mature fields generate low revenues. Considerable investments are often needed to continue with the production of oil at a mature field until the field is depleted because the...master thesis 2013
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Patriarca, C. (author)The non-destructive evaluation with the aim of characterizing objects before or after treatment has taken place, and the monitoring of long-term performance is analyzed in this thesis. Generally, these test methods measure material properties or changes in these properties that decision makers are interested in. There is a variety of non...doctoral thesis 2013
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Gilli, L. (author)This thesis presents the development and the implementation of an uncertainty propagation algorithm based on the concept of spectral expansion. The first part of the thesis is dedicated to the study of uncertainty propagation methodologies and to the analysis of spectral techniques. The concepts introduced within this preliminary analysis are...doctoral thesis 2013
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Loeven, G.J.A. (author)When modeling physical systems, several sources of uncertainty are present. For example, variability in boundary conditions like free stream velocity or ambient pressure are always present. Furthermore, uncertainties in geometry arise from production tolerances, wear or unknown deformations under loading. Uncertainties in computational fluid...doctoral thesis 2010
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Loeven, G.J.A. (author), Bijl, H. (author)In this paper a Two-Step approach is presented for uncertainty quantification for expensive problems with multiple uncertain parameters. Both steps are performed using the Probabilistic Collocation method. The first step consists of a sensitivity analysis to identify the most important parameters of the problem. The sensitivity derivatives are...journal article 2009
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Witteveen, J.A.S. (author), Bijl, H. (author)The Unsteady Adaptive Stochastic Finite Elements (UASFE) approach is a robust and efficient uncertainty quantification method for resolving the effect of random parameters in unsteady simulations. In this paper, it is shown that the underlying Adaptive Stochastic Finite Elements (ASFE) method for steady problems based on Newton-Cotes quadrature...journal article 2009
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Witteveen, J.A.S. (author), Bijl, H. (author)A robust and efficient uncertainty quantification method is presented for resolving the effect of uncertainty on the behavior of multi-physics systems. The extrema diminishing method in probability space maintains a bounded error due to the interpolation of deterministic samples at constant phase in a transonic airfoil flutter problem.conference paper 2009