Searched for: subject:"secondary%5C+flow"
(1 - 18 of 18)
document
Gloger, Jonathan (author)
Large-scale liquid rocket engines require high-speed turbopumps to inject cryogenic propellants into the combustion chamber. Modeling the impact of secondary path and leakage flows on the performance and axial thrust of the pump is critical during the early design phase. Previous studies derived simplified models and empirical correlations to...
master thesis 2018
document
Bregman, Martijn (author)
This thesis presents a new methodology for representing the effect of spiral flow on the bed shear stress magnitude and direction, using a low-vertical-resolution three-dimensional model. Furthermore, it discusses the performance of the new methodology in comparison with conventional high-vertical-resolution three-dimensional and depth-averaged...
master thesis 2018
document
Mingardo, Giacomo (author)
The threat of global warming made the increase of efficiency a crucial objective for future power plants and aero engines. As secondary flow is a major source of aerodynamic losses in turbines, its mitigation is critical to enable efficient designs. However, the suppression of secondary flow formation is challenging due to the complexity of the...
master thesis 2018
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van Til, S.W. (author)
The fairway connecting Holwerd and Nes forms the main transport route between Friesland and Ameland (the Dutch Wadden Sea). It consists of several tidal channels that funnel the majority of the tidal currents propagating through the tidal basin. Over the past decades, several channel bends have expanded leading to a fairway length-increase of...
master thesis 2017
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Ebrahimi, A. (author), Naranjani, Benyamin (author)
In this study, a flat-plate channel configured with pyramidal protrusions are numerically analysed for the first time. Simulations of laminar single-phase fluid flow and heat transfer characteristics are developed using a finite-volume approach under steady-state condition. Pure water is selected as the coolant and its thermo-physical...
journal article 2016
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Arailopoulos, I. (author)
Depth-averaged morphological computations using Delft3D tend to produce ‘strange’, results for river bends when the sediment transport formulas of Van Rijn are used. Even pools in inner bend regions and bars in outer bend regions can result from the model. The objective of the present thesis is to identify the cause of the problem and propose...
master thesis 2014
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Ottevanger, W. (author)
Meandering rivers are interesting features of the landscape due to their aesthetically pleasing forms. There is an abundance of scientific studies on meandering rivers, however, their behaviour is still not fully understood. The complexity of the flow, bed morphodynamics and bank stability, the related uncertainties in water and sediment motion,...
doctoral thesis 2013
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Ottevanger, W. (author), Blanckaert, K. (author), Uijttewaal, W.S.J. (author), De Vriend, H.J. (author)
Reduced-order models remain essential tools for meander modeling, especially for processes at large length scales and long time scales, probabilistic simulations, rapid assessments, or when input data are scarce or uncertain. Present reduced-order meander models consider their dependent variables either as small-amplitude variations compared to...
journal article 2013
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Blanckaert, K. (author)
The migration rate of sharp meander bends exhibits large variance and indicates that some sharply curved bends tend to stabilize. These observations remain unexplained. This paper examines three hydrodynamic processes in sharp bends with fixed banks and discusses their morphological implications: secondary flow saturation, outer-banks cells, and...
journal article 2011
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Blanckaert, K. (author), De Vriend, H.J. (author)
Despite the rapid evolution of computational power, simulation of meander dynamics by means of reduced and computationally less expensive models remains practically relevant for investigation of large?scale and long?term processes, probabilistic predictions, or rapid assessments. Existing meander models are invariantly based on the assumptions...
journal article 2010
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Blanckaert, K.J.F. (author)
The paper investigates the influence of relative bend curvature on secondary flow, energy losses, and turbulence in sharp open-channel bends. These processes are important in natural streams with respect to sediment transport, the bathymetry and planimetry, mixing and spreading of pollutants, heat, oxygen, nutrients and biological species, and...
journal article 2009
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Zeng, J. (author), Constantinescu, G. (author), Blanckaert, K. (author), Weber, L. (author)
This paper focuses on experiments and simulations conducted in very sharp open-channel bends with flat and equilibrium bathymetry, corresponding to the initial and final phases of the erosion and deposition processes, respectively. The study of flow in curved open bends is relevant for flow in natural river configurations, as most river reaches...
journal article 2008
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Jongbloed, J.W. (author)
The flow in a river bend has a large influence on the cross-sectional profile of the bend. Due to the curvature of the bend a secondary flow, which is perpendicular to the main flow, occurs. The secondary flow is directed outwards in the upper part of the cross-section and inwards in the lower part of the cross-section. It causes by means of the...
master thesis 1996
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Bernard, R.S. (author), Schneider, M.L. (author)
Without some correction for the interaction between lateral curvature and vertically nonuniform velocity, depth-averaged numerical models cannot predict the gradual migration of high velocity toward the outside of channel bends. Conventional depth-averaging does not account for the curvature-induced secondary flow that gives rise to the...
report 1992
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Booij, R. (author), Pennekamp, J.G.C. (author)
Prediction of bottom changes in rivers and tidal channels require a thorough knowledge of the secondary flow, as this flow gives rise to bottom slopes transverse to the main flow direction. In the model used in this research, the computation of the secondary flow field is based upon an, independently computed, depth averaged main flow field. In...
report 1984
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Pennekamp, J.G.S. (author), Booij, R. (author)
For the computation of depth averaged flows in tidal channels and rivers a recently developed fully implicit finite difference method of the ADI-type proved vastly superior to the partly explicit variants, commonly used. The fully implicit variant allowed a relatively large time step in combination with arealistic lateral diffusion coefficient....
report 1984
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de Bruin, A.C. (author)
The three dimensional flow field around delta wings with leading-edge vortex flow can be computed with panel methods. However, secondary flow separation may occur on the leeward surface of the wing. The associated free vortex sheet can be modeled in the potential flow calculation method, if the location of the secondary separation is provided by...
report 1983
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Booij, R. (author), Pennekamp, J.G.C. (author)
Knowledge of the secondary flow is essential for predictions about the morphology of alluvial bottoms in tidal channels. In this research the determination of the secondary flow is based on a known depth averaged velocity field. The depth averaged velocities must be computed with a high accuracy in order to make possible a reasonable...
report 1983
Searched for: subject:"secondary%5C+flow"
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