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Flow patterns in ascending aortic aneurysms: Determining the role of hypertension using phase contrast magnetic resonance and computational fluid dynamics

Ramaekers, M. J.F.G. (author), van der Vlugt, I.B. (author), Westenberg, J. J.M. (author), Perinajová, R. (author), Lamb, H. J. (author), Wildberger, J. E. (author), Kenjeres, S. (author), Schalla, S. (author)

Thoracic aortic aneurysm (TAA) is a local dilation of the thoracic aorta. Although universally used, aneurysm diameter alone is a poor predictor of major complications such as rupture. There is a need for better biomarkers for risk assessment that also reflect the aberrant flow patterns found in TAAs. Furthermore, hypertension is often...

journal article 2024

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Influence of aortic aneurysm on the local distribution of NO and O₂ using image-based computational fluid dynamics

Perinajová, R. (author), Álvarez-Cuevas, Concepción Borrás (author), Juffermans, Joe (author), Westenberg, Jos (author), Lamb, Hildo (author), Kenjeres, S. (author)

There is a pressing need to establish novel biomarkers to predict the progression of thoracic aortic aneurysm (TAA) dilatation. Aside from hemodynamics, the roles of oxygen (O₂) and nitric oxide (NO) in TAA pathogenesis are potentially significant. As such, it is imperative to comprehend the relationship between aneurysm presence...

journal article 2023

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Laboratory Investigation of Tomography-Controlled Continuous Steel Casting

Glavinić, Ivan (author), Muttakin, Imamul (author), Abouelazayem, Shereen (author), Blishchik, A. (author), Stefani, Frank (author), Eckert, Sven (author), Soleimani, Manuchehr (author), Saidani, Iheb (author), Kenjeres, S. (author)

More than 96% of steel in the world is produced via the method of continuous casting. The flow condition in the mould, where the initial solidification occurs, has a significant impact on the quality of steel products. It is important to have timely, and perhaps automated, control of the flow during casting. This work presents a new concept...

journal article 2022

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Extracardiac conduit adequacy along the respiratory cycle in adolescent Fontan patients

Rijnberg, Friso M. (author), van der Woude, S.F.S. (author), Hazekamp, Mark G. (author), Van Den Boogaard, Pieter J. (author), Lamb, Hildo J. (author), Terol Espinosa De Los Monteros, Covadonga (author), Kenjeres, S. (author), Karim, Tawab (author), Jongbloed, Monique R.M. (author)

OBJECTIVES: Adequacy of 16-20mm extracardiac conduits for adolescent Fontan patients remains unknown. This study aims to evaluate conduit adequacy using the inferior vena cava (IVC)-conduit velocity mismatch factor along the respiratory cycle. METHODS: Real-time 2D flow MRI was prospectively acquired in 50 extracardiac (16-20mm conduits)...

journal article 2022

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Non-uniform mixing of hepatic venous flow and inferior vena cava flow in the Fontan conduit

Rijnberg, Friso M. (author), van der Woude, S.F.S. (author), van Assen, Hans C. (author), Juffermans, J.F. (author), Hazekamp, Mark G. (author), Jongbloed, Monique R.M. (author), Kenjeres, S. (author), Lamb, Hildo J. (author), Westenberg, Jos J.M. (author)

Fontan patients require a balanced hepatic blood flow distribution (HFD) to prevent pulmonary arteriovenous malformations. Currently, HFD is quantified by tracking Fontan conduit flow, assuming hepatic venous (HV) flow to be uniformly distributed within the Fontan conduit. However, this assumption may be unvalid leading to inaccuracies in HFD...

journal article 2021

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Modeling of a continuous physical vapor deposition process: Mass transfer limitations by evaporation rate and sonic choking

Vesper, J.E. (author), Obiji, Chibuikem S. (author), Westerwaal, Ruud (author), Boelsma, Christiaan (author), Kenjeres, S. (author), Kleijn, C.R. (author)

In recent years, Physical Vapor Deposition has been advanced to a continuous process which makes it amenable for in-line, high-quality and energy-efficient galvanization. To achieve the high and uniform mass flow required for in-line production, a Vapor Distribution Box is used, in which the zinc is evaporated. The zinc fills the Vapor...

journal article 2021

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Hemodynamic Study of a Patient-Specific Intracranial Aneurysm: Comparative Assessment of Tomographic PIV, Stereoscopic PIV, In Vivo MRI and Computational Fluid Dynamics

Wu, X. (author), Gurzing, S.D. (author), Schinkel, C.V. (author), Toussaint, Merel (author), Perinajová, R. (author), van Ooij, Pim (author), Kenjeres, S. (author)

Introduction: Wall shear stress (WSS) is associated with the growth and rupture of an intracranial aneurysm. To reveal their underlying connections, many image-based computational fluid dynamics (CFD) studies have been conducted. However, the methodological validations using both in vivo medical imaging and in vitro optical flow measurements...

journal article 2021

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Echo planar imaging–induced errors in intracardiac 4D flow MRI quantification

Westenberg, Jos J.M. (author), van Assen, Hans C. (author), van den Boogaard, Pieter J. (author), Goeman, Jelle J. (author), Saaid, Hicham (author), Voorneveld, J.D. (author), Bosch, Johan (author), Kenjeres, S. (author), Claessens, Tom (author)

Purpose: To assess errors associated with EPI-accelerated intracardiac 4D flow MRI (4DEPI) with EPI factor 5, compared with non-EPI gradient echo (4DGRE). Methods: Three 3T MRI experiments were performed comparing 4DEPI to 4DGRE: steady flow through straight tubes, pulsatile flow in a left-ventricle phantom, and intracardiac flow in 10...

journal article 2021

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Effect of double-diffusive convection with cross gradients on heat and mass transfer in a cubical enclosure with adiabatic cylindrical obstacles

Chakkingal, M. (author), Voigt, Roland (author), Kleijn, C.R. (author), Kenjeres, S. (author)

We investigate natural convection driven by a horizontal temperature gradient and a vertical concentration gradient in fluid-filled enclosures with obstructions inside it. Within the domain, nine adiabatic and impermeable cylinders are placed, occupying 30% of the domain volume. The Boussinesq approximation is used to account for density...

journal article 2020

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Assisting and opposing mixed convection with conjugate heat transfer in a differentially heated cavity filled with coarse-grained porous media

Chakkingal, M. (author), de Geus, Julia (author), Kenjeres, S. (author), Ataei Dadavi, I. (author), Tummers, M.J. (author), Kleijn, C.R. (author)

We report numerical simulations of assisting and opposing mixed convection in a side-heated, side-cooled cavity packed with relatively large solid spheres. The mixed convection is generated by imposing a movement on the isothermal vertical walls, either in or opposite to the direction of natural convection flow. For a fluid Prandtl number of...

journal article 2020

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Numerical analysis of natural convection in a differentially heated packed bed with non-uniform wall temperature

Chakkingal, M. (author), Kenjeres, S. (author), Ataei Dadavi, I. (author), Tummers, M.J. (author), Kleijn, C.R. (author)

We report numerical simulations of natural convection and conjugate heat transfer in a differentially heated cubical cavity packed with relatively large hydrogel beads (d/L=0.2) in a Simple Cubic Packing configuration. We study the influence of a spatially non-uniform, sinusoidally varying, wall temperature on the local flow and heat transfer...

journal article 2020

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4-D Echo-Particle Image Velocimetry in a Left Ventricular Phantom

Voorneveld, J.D. (author), Saaid, H. (author), Schinkel, C.V. (author), Radeljic, Nikola (author), Lippe, Boris (author), Gijsen, F.J.H. (author), van der Steen, A.F.W. (author), de Jong, N. (author), Claessens, Tom (author), Vos, H.J. (author), Kenjeres, S. (author), Bosch, Johan G. (author)

Left ventricular (LV) blood flow is an inherently complex time-varying 3-D phenomenon, where 2-D quantification often ignores the effect of out-of-plane motion. In this study, we describe high frame rate 4-D echocardiographic particle image velocimetry (echo-PIV) using a prototype matrix transesophageal transducer and a dynamic LV phantom for...

journal article 2020

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Tomographic PIV in a model of the left ventricle: 3D flow past biological and mechanical heart valves

Saaid, Hicham (author), Voorneveld, Jason (author), Schinkel, C.V. (author), Westenberg, Jos (author), Gijsen, F.J.H. (author), Segers, Patrick (author), Verdonck, Pascal (author), de Jong, N. (author), Kenjeres, S. (author)

Left ventricular flow is intrinsically complex, three-dimensional and unsteady. Its features are susceptible to cardiovascular pathology and treatment, in particular to surgical interventions involving the valves (mitral valve replacement). To improve our understanding of intraventricular fluid mechanics and the impact of various types of...

journal article 2019

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Numerical analysis of natural convection with conjugate heat transfer in coarse-grained porous media

Chakkingal, M. (author), Kenjeres, S. (author), Ataei Dadavi, I. (author), Tummers, M.J. (author), Kleijn, C.R. (author)

We report numerical simulations of fluid natural convection with conjugate heat transfer in a bottom-heated, top-cooled cubical cavity packed with relatively large (d/L=0.2) solid spheres in a Body Centred Tetragonal (BCT) configuration. We study largely varying solid-to-fluid thermal conductivity ratios between 0.3 and 198, for a fluid...

journal article 2019

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Real-time control of the mould flow in a model of continuous casting in frame of the TOMOCON project

Wondrak, T. (author), Hampel, U. (author), Ratajczak, M. (author), Glavinic, I. (author), Stefani, F. (author), Eckert, S. (author), Van Der Plas, D. (author), Pennerstorfer, P. (author), Soleimani, M. (author), Blishchik, A. (author), Kenjeres, S. (author)

In continuous casting, the flow structure of the liquid steel in the mould and the two-phase distribution in the submerged entry nozzle (SEN) are crucial for the quality of the produced steel. In order to effectively control the flow in the mould by electromagnetic brakes (EMBrs) and the injection of gas into the SEN, even a rough knowledge...

journal article 2018

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Simulating liquid droplets: A quantitative assessment of lattice Boltzmann and Volume of Fluid methods

Mukherjee, S. (author), Zarghami, A. (author), Haringa, C. (author), van As, K. (author), Kenjeres, S. (author), van den Akker, H.E.A. (author)

While various multiphase flow simulation techniques have found acceptance as predictive tools for processes involving immiscible fluids, none of them can be considered universally applicable. Focusing on accurate simulation of liquid-liquid emulsions at the scale of droplets, we present a comparative assessment of the single-component...

journal article 2018

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Marangoni driven turbulence in high energy surface melting processes

Kidess, A. (author), Kenjeres, S. (author), Righolt, B.W. (author), Kleijn, C.R. (author)

Experimental observations of high-energy surface melting processes, such as laser welding, have revealed unsteady, often violent, motion of the free surface of the melt pool. Surprisingly, no similar observations have been reported in numerical simulation studies of such flows. Moreover, the published simulation results fail to predict the...

journal article 2016

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Fractality of pulsatile flow in speckle images

Nemati, M. (author), Kenjeres, S. (author), Urbach, Paul (author), Bhattacharya, N. (author)

The scattering of coherent light from a system with underlying flow can be used to yield essential information about dynamics of the process. In the case of pulsatile flow, there is a rapid change in the properties of the speckle images. This can be studied using the standard laser speckle contrast and also the fractality of images. In this...

journal article 2016

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On Recent Progress in Modelling and Simulations of Multi-scale Transfer of Mass, Momentum and Particles in Bio-medical Applications

Kenjeres, S. (author)

We present a short overview of some of our most recent work that combines the mathematical modeling, advanced computer simulations and state-of-the-art experimental techniques of physical transport phenomena in various bio-medical applications. In the first example, we tackle predictions of complex blood flow patterns in the patient-specific...

journal article 2016

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On Recent Progress in Modelling and Simulations of Multi-scale Transfer of Mass, Momentum and Particles in Bio-medical Applications

Kenjeres, S. (author)

We present a short overview of some of our most recent work that combines the mathematical modeling, advanced computer simulations and state-of-the-art experimental techniques of physical transport phenomena in various bio-medical applications. In the first example, we tackle predictions of complex blood flow patterns in the patient-specific...

journal article 2015