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Energy-stable discretization of the one-dimensional two-fluid model

Buist, J.F.H. (author), Sanderse, B. (author), Dubinkina, S. (author), Oosterlee, C. W. (author), Henkes, R.A.W.M. (author)

In this paper we present a complete framework for the energy-stable simulation of stratified incompressible flow in channels, using the one-dimensional two-fluid model. Building on earlier energy-conserving work on the basic two-fluid model, our new framework includes diffusion, friction, and surface tension. We show that surface tension can...

journal article 2024

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Magnetic particle tracking: A semi-algebraic solution

Buist, K. A. (author), Nijssen, Tim M.J. (author)

Magnetic Particle Tracking (MPT) is a relatively new non-invasive measurement technique which is often used to study dense granular flow. Its basic principle relies on tracking the movement of a single magnetic tracer by means of measuring the magnetic field strength at a suitable distance from the tracer. By assumption of a magnetic dipole...

journal article 2023

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Energy-consistent formulation of the pressure-free two-fluid model

Buist, J.F.H. (author), Sanderse, Benjamin (author), Dubinkina, Svetlana (author), Oosterlee, C.W. (author), Henkes, R.A.W.M. (author)

The pressure-free two-fluid model (PFTFM) is a recent reformulation of the one-dimensional two-fluid model (TFM) for stratified incompressible flow in ducts (including pipes and channels), in which the pressure is eliminated through intricate use of the volume constraint. The disadvantage of the PFTFM was that the volumetric flow rate had to...

journal article 2023

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A novel pressure-free two-fluid model for one-dimensional incompressible multiphase flow

Sanderse, B. (author), Buist, J.F.H. (author), Henkes, R.A.W.M. (author)

A novel pressure-free two-fluid model formulation is proposed for the simulation of one-dimensional incompressible multiphase flow in pipelines and channels. The model is obtained by simultaneously eliminating the volume constraint and the pressure from the widely used two-fluid model (TFM). The resulting ‘pressure-free two-fluid model’ (PF...

journal article 2021

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Fluidization of spherical versus elongated particles: Experimental investigation using magnetic particle tracking

Mema, I. (author), Buist, Kay A. (author), Kuipers, J. A.M. (author), Padding, J.T. (author)

In biomass processing fluidized beds are used to process granular materials where particles typically possess elongated shapes. However, for simplicity, in computer simulations particles are often considered spherical, even though elongated particles experience more complex particle–particle interactions as well as different hydrodynamic...

journal article 2020

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Parallelization of a stochastic Euler-Lagrange model applied to large scale dense bubbly flows

Kamath, S. (author), Masterov, M. V. (author), Padding, J.T. (author), Buist, K. A. (author), Baltussen, M. W. (author), Kuipers, J. A.M. (author)

A parallel and scalable stochastic Direct Simulation Monte Carlo (DSMC) method applied to large-scale dense bubbly flows is reported in this paper. The DSMC method is applied to speed up the bubble-bubble collision handling relative to the Discrete Bubble Model proposed by Darmana et al. (2006) [1]. The DSMC algorithm has been modified and...

journal article 2020

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Droplet collisions of water and milk in a spray with Langevin turbulence dispersion

Finotello, Giulia (author), Padding, J.T. (author), Buist, Kay A. (author), Jongsma, Alfred (author), Innings, Fredrik (author), Kuipers, J. A.M. (author)

In this work we investigate droplet-droplet collision interactions in a spray system using an Eulerian-Lagrangian model with subgrid turbulence dispersion. The effect of different droplet viscosities on the type and frequency of droplet collision is investigated, knowledge of which is essential for industrial processes such as spray drying...

journal article 2019

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Numerical investigation of droplet-droplet collisions in a water and milk spray with coupled heat and mass transfer

Finotello, Giulia (author), Padding, J.T. (author), Buist, Kay A. (author), Schijve, Annelien (author), Jongsma, Alfred (author), Innings, Fredrik (author), Kuipers, J.A.M. (author)

Large scale simulation models can aid in improving the design of spray dryers. In this work an Eulerian-Lagrangian model with coupled gas phase and droplet heat and mass transfer balances is used to study airflow dynamics, temperature and humidity profiles at different positions in the spray. The turbulent gas flow is solved using large eddy...

journal article 2019

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The dynamics of milk droplet–droplet collisions

Finotello, Giulia (author), Kooiman, Roeland F. (author), Padding, J.T. (author), Buist, Kay A. (author), Jongsma, Alfred (author), Innings, Fredrik (author), Kuipers, J. A.M. (author)

Spray drying is an important industrial process to produce powdered milk, in which concentrated milk is atomized into small droplets and dried with hot gas. The characteristics of the produced milk powder are largely affected by agglomeration, combination of dry and partially dry particles, which in turn depends on the outcome of a collision...

journal article 2018

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Nonspherical particles in a pseudo-2D fluidized bed: Experimental study

Mahajan, V.V. (author), Padding, J.T. (author), Nijssen, Tim M.J. (author), Buist, Kay A. (author), Kuipers, J.R. (author)

Fluidization is widely used in industries and has been extensively studied, both experimentally and theoretically, in the past. However, most of these studies focus on spherical particles while in practice granules are rarely spherical. Particle shape can have a significant effect on fluidization characteristics. It is therefore important to...

journal article 2018

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Stochastic DSMC method for dense bubbly flows: Methodology

Kamath, S. (author), Padding, J.T. (author), Buist, K. A. (author), Kuipers, J.R. (author)

A stochastic Direct Simulation Monte Carlo (DSMC) method has been extended for handling bubble-bubble and bubble-wall collisions. Bubbly flows are generally characterized by highly correlated velocities due to presence of the surrounding liquid. The DSMC method has been improved to account for these kind of correlated collisions along with a...

journal article 2018

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Experimental investigation of non-Newtonian droplet collisions: the role of extensional viscosity

Finotello, Giulia (author), De, Shauvik (author), Vrouwenvelder, Jeroen C.R. (author), Padding, J.T. (author), Buist, Kay A. (author), Jongsma, Alfred (author), Innings, Fredrik (author), Kuipers, J. A.M. (author)

We investigate the collision behaviour of a shear thinning non-Newtonian fluid xanthan, by binary droplet collision experiments. Droplet collisions of non-Newtonian fluids are more complex than their Newtonian counterpart as the viscosity no longer remains constant during the collision process. Despite the complex collision dynamics, we are...

journal article 2018

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Experimental study on orientation and de-mixing phenomena of elongated particles in gas-fluidized beds

Boer, L. (author), Buist, K. A. (author), Deen, N. G. (author), Padding, J.T. (author), Kuipers, J. A.M. (author)

In this experimental study the segregation behavior for fluidized mixtures of spherical and cylindrical particles is investigated. In industry, fluidization of particles featuring a wide range of shapes is common in various applications such as biomass gasification, drying applications, food processing and production of pharmaceuticals....

journal article 2018

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Three-dimensional fluidized beds with rough spheres: Validation of a Two Fluid Model by Magnetic Particle Tracking and discrete particle simulations

Yang, L. (author), Padding, J.T. (author), Buist, K. A. (author), Kuipers, J.R. (author)

Two fluid model simulations based on our recently introduced kinetic theory of granular flow (KTGF) for rough spheres and rough walls, are validated for the first time for full three-dimensional (3D) bubbling fluidized beds. The validation is performed by comparing with experimental data from Magnetic Particle Tracking and more detailed...

journal article 2017

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Magnetic particle tracking for nonspherical particles in a cylindrical fluidized bed

Buist, Kay A. (author), Jayaprakas, Pavithra (author), Kuipers, J.A.M. (author), Deen, Niels G. (author), Padding, J.T. (author)

In granular flow operations, often particles are nonspherical. This has inspired a vast amount of research in understanding the behavior of these particles. Various models are being developed to study the hydrodynamics involving nonspherical particles. Experiments however are often limited to obtain data on the translational motion only. This...

journal article 2017

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Undifferenced and single differenced GNSS noise analysis through a constrained baseline vector

Buist, P.J. (author), Imparato, D. (author)

GNSS noise characteristics can be obtained by short and zero baseline analysis, for both pseudorange and carrier phase measurements. Differencing observations from a GNSS satellite tracked by two GNSS receivers (connected to the same or different antennas) will explicitly eliminate common errors. In this contribution, the known baseline vector...

conference paper 2014

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Multi-platform Integrated Positioning and Attitude Determination using GNSS

Buist, P.J. (author)

There is trend in spacecraft engineering toward distributed systems where a number of smaller spacecraft work as a larger satellite. However, in order to make the small satellites work together as a single large platform, the precise relative positions (baseline) and orientations (attitude) of the elements of the formation have to be estimated....

doctoral thesis 2013

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Match filtering approach for signal acquisition in radio-pulsar navigation

Heusdens, R. (author), Engelen, S. (author), Buist, P.J. (author), Noroozi, A. (author), Sundaramoorthy, P.P. (author), Verhoeven, C.J.M. (author), Bentum, M. (author), Gill, E.K.A. (author)

Pulsars with their periodic pulses and known positions are ideal beacons for navigation. The challenge, however, is the detection of the very weak pulsar signals that are submerged in noise. Radio based approaches allow the use of advanced techniques and methods for the detection and acquisition of such weak signals. In this paper, an effective...

conference paper 2012

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Automated lane identification using precise point positioning: An affordable and accurate GPS technique

Knoop, V.L. (author), Buist, P.J. (author), Tiberius, C.C.J.M. (author), Van Arem, B. (author)

lecture notes 2012

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Improving the GNSS attitude ambiguity success rate with the multivariate constrained LAMBDA method

Giorgi, G. (author), Teunissen, P.J.G. (author), Verhagen, S. (author), Buist, P.J. (author)

GNSS Attitude Determination is a valuable technique for the estimation of platform orientation. To achieve high accuracies on the angular estimations, the GNSS carrier phase data has to be used. These data are known to be affected by integer ambiguities, which must be correctly resolved in order to exploit the higher precision of the phase...

conference paper 2009