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JJWA van Loon
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3 records found
1
Journal article
(2017)
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Carole Leguy, Rene Delfos, MAthieu Pourquie, Christian Poelma, Jerry Westerweel, JJWA van Loon
A Random Positioning Machine (RPM) is a device used to study the role of gravity on biological systems. This is accomplished through continuous reorientation of the sample such that the net influence of gravity is randomized over time. The aim of this study is to predict fluid flow behavior during such RPM simulated microgravity studies, which may explain differences found between RPM and space flight experiments. An analytical solution is given for a cylinder as a model for an experimental container. Then, a dual-axis rotating frame is used to mimic the motion characteristics of an RPM with sinusoidal rotation frequencies of 0.20.2 Hz and 0.10.1 Hz while Particle Image Velocimetry is used to measure the velocity field inside a flask. To reproduce the same experiment numerically, a Direct Numerical Simulation model is used. The analytical model predicts that an increase in the Womersley number leads to higher shear stresses at the cylinder wall and decrease in fluid angular velocity inside the cylinder. The experimental results show that periodic single-axis rotation induces a fluid motion parallel to the wall and that a complex flow is observed for two-axis rotation with a maximum wall shear stress of 8.08.0 mPa (80 mdyne/cm2mdyne/cm2). The experimental and numerical results show that oscillatory motion inside an RPM induces flow motion that can, depending on the experimental samples, reduce the quality of the simulated microgravity. Thus, it is crucial to determine the appropriate oscillatory frequency of the axes to design biological experiments.0
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A Random Positioning Machine (RPM) is a device used to study the role of gravity on biological systems. This is accomplished through continuous reorientation of the sample such that the net influence of gravity is randomized over time. The aim of this study is to predict fluid flow behavior during such RPM simulated microgravity studies, which may explain differences found between RPM and space flight experiments. An analytical solution is given for a cylinder as a model for an experimental container. Then, a dual-axis rotating frame is used to mimic the motion characteristics of an RPM with sinusoidal rotation frequencies of 0.20.2 Hz and 0.10.1 Hz while Particle Image Velocimetry is used to measure the velocity field inside a flask. To reproduce the same experiment numerically, a Direct Numerical Simulation model is used. The analytical model predicts that an increase in the Womersley number leads to higher shear stresses at the cylinder wall and decrease in fluid angular velocity inside the cylinder. The experimental results show that periodic single-axis rotation induces a fluid motion parallel to the wall and that a complex flow is observed for two-axis rotation with a maximum wall shear stress of 8.08.0 mPa (80 mdyne/cm2mdyne/cm2). The experimental and numerical results show that oscillatory motion inside an RPM induces flow motion that can, depending on the experimental samples, reduce the quality of the simulated microgravity. Thus, it is crucial to determine the appropriate oscillatory frequency of the axes to design biological experiments.0
Co-evolution of smart energy products and services
A novel approach towards smart grids
Conference paper
(2016)
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A. Reinders, Moreno de Respinis, E. Gultekin, B. van Mierlo, E. Markočič, B. Hassewend, Carla Robledo, Ioulia Papaioannou, Ad van Wijk, M. Lagler, E. Schmautzer, T. Höhn, J. van Loon, L. Fickert, A Stekelenburg, F. Bliek, W. Schram, W. van Sark, T. Esteri, S. Übermasser, F. Lehfuss
In this paper we present our project on interdisciplinary evaluations of existing smart grid environments regarding (1) the technical performance of smart energy products and services, (2) end users perceptions, (3) stakeholder processes and (4) market aspects. Our evaluations are based on data and information originating from real life pilots and demonstration projects in the field of smart grids in residential areas in the Netherlands and in Austria. The so-called CESEPS project is executed in the European ERA-Net Smart Grids Plus program. CESEPS stands for Co-Evolution of Smart Energy Product and Services. Its main objective is to support the development of smart energy products and services for local smart grids that better respond to the demands and concerns of all stakeholders in terms of performance, cost, reliability, safety and robustness, sustainability and energy-efficiency, and end users' comfort. Besides comparative data analyses and user surveys, this three year project comprises simulation activities to model existing and innovative smart grid energy products to evaluate their feasibility, given the aspects above mentioned. In this paper our approach will be explained and illustrated by several examples of ongoing subtopics of research and knowledge dissemination among stakeholders in the smart grid sector.
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In this paper we present our project on interdisciplinary evaluations of existing smart grid environments regarding (1) the technical performance of smart energy products and services, (2) end users perceptions, (3) stakeholder processes and (4) market aspects. Our evaluations are based on data and information originating from real life pilots and demonstration projects in the field of smart grids in residential areas in the Netherlands and in Austria. The so-called CESEPS project is executed in the European ERA-Net Smart Grids Plus program. CESEPS stands for Co-Evolution of Smart Energy Product and Services. Its main objective is to support the development of smart energy products and services for local smart grids that better respond to the demands and concerns of all stakeholders in terms of performance, cost, reliability, safety and robustness, sustainability and energy-efficiency, and end users' comfort. Besides comparative data analyses and user surveys, this three year project comprises simulation activities to model existing and innovative smart grid energy products to evaluate their feasibility, given the aspects above mentioned. In this paper our approach will be explained and illustrated by several examples of ongoing subtopics of research and knowledge dissemination among stakeholders in the smart grid sector.