Brunel Institute for Bioengineering (BIB) is a multidisciplinary innovative research and development organisation where ideas turn into reality within industrial timescales. Founded in 1983 by Professor Heinz Wolff, it is a financially self-supporting organisation specialising in science and engineering for space, health care and contract work for industry. http://bura.brunel.ac.uk/handle/2438/154 2013-05-24T04:06:07Z 2013-05-24T04:06:07Z De Folter, Jozefus Johannes Martinus http://bura.brunel.ac.uk/handle/2438/7157 2013-01-21T11:11:07Z 2013-01-01T00:00:00Z

Title: Advanced modelling and visualisation of liquid-liquid separations of complex sample components, with variable phase distribution and mode of operation Authors: De Folter, Jozefus Johannes Martinus Abstract: This research is about liquid-liquid chromatography modelling. While the main focus was on liquid-liquid chromatography, where the stationary and mobile phases are both liquid, theory of different types of chromatography, including the currently most used techniques, were considered as well. The main goal of this research was to develop a versatile liquid-liquid separation model, able to model all potential operating scenarios and modes of operation. A second goal was to create effective and usable interfaces to such a model, implying primarily information visualisation, and secondarily educative visualisation. The first model developed was a model based on Counter-Current Distribution. Next a new more elemental model was developed, the probabilistic model, which better models continuous liquid-liquid chromatography techniques. Finally, a more traditional model was developed using transport theory. These models were used and compared to experimental data taken from literature. The models were demonstrated to model all main liquid-liquid chromatography techniques, incorporated the different modes of operation, and were able to accurately model many sample components and complex sample injections. A model interface was developed, permitting functional and effective model configuration, exploration and analysis using visualisation and interactivity. Different versions of the interface were then evaluated using questionnaires, group interviews and Insight Evaluation. The visualisation and interactivity enhancements have proven to contribute understanding and insight of the underlying chromatography process. This also proved the value of the Insight Evaluation method, providing valuable qualitative evaluation results desired for this model interface evaluation. A prototype of a new graphical user interface developed, and showed great potential for combining model parameter input and exploring the liquid-liquid chromatography processes. Additionally, a new visualisation method was developed that can accurately visualise different modes of operation. This was used to create animations, which were also evaluated. The results of this evaluation show the new visualisation helps understanding of the liquid-liquid chromatography process amongst CCC novices. The model software will be a valuable tool for industry for predicting, evaluating and validating experimental separations and production processes. While effective models already existed, the use of interactive visualisation permits users to explore the relationship between parameters and performances in a simpler yet more powerful way. It will also be a valuable tool for academia for teaching & training, both staff and students, on how to use the technology. Prior to this work no such tool existed or existing tools were limited in their accessibility and educational value. Description: This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.

2013-01-01T00:00:00Z Shiferaw, D Mahmoud, M Karayiannis, TG Kenning, DBR 2nd Micro and Nano Flows Conference (MNF2009) http://bura.brunel.ac.uk/handle/2438/6952 2012-10-12T09:31:28Z 2009-01-01T00:00:00Z

Title: One-dimensional mechanistic model for flow boiling pressure drop in small- to micro- passages Authors: Shiferaw, D; Mahmoud, M; Karayiannis, TG; Kenning, DBR; 2nd Micro and Nano Flows Conference (MNF2009) Abstract: Accurate predictions of two-phase pressure drop in small to micro diameter passages are necessary for the design of compact and ultra-compact heat exchangers which find wide application in process and refrigeration industries and in cooling of electronics. A semi-mechanistic model of boiling two-phase pressure drop in the confined bubble regime is formulated, following the three-zone approach of Thome et al. (2004) for heat transfer. The total pressure drop is calculated by time-averaging the respective pressure drop values of single-phase liquid, elongated bubble with a thin liquid film and single-phase vapour. The model results were compared with experimental data collected for a wide range of diameter tubes (4.26, 2.88, 2.02, 1.1 and 0.52 mm) for R134a at 6 – 12 bar. Description: This paper was presented at the 2nd Micro and Nano Flows Conference (MNF2009), which was held at Brunel University, West London, UK. The conference was organised by Brunel University and supported by the Institution of Mechanical Engineers, IPEM, the Italian Union of Thermofluid dynamics, the Process Intensification Network, HEXAG - the Heat Exchange Action Group and the Institute of Mathematics and its Applications.

2009-01-01T00:00:00Z Gedupudi, S Kenning, DBR Karayiannis, TG 2nd Micro and Nano Flows Conference (MNF2009) http://bura.brunel.ac.uk/handle/2438/6951 2012-10-12T09:27:08Z 2009-01-01T00:00:00Z

Title: 1-D modelling of pressure fluctuations due to confined bubble growth during flow boiling in a microchannel Authors: Gedupudi, S; Kenning, DBR; Karayiannis, TG; 2nd Micro and Nano Flows Conference (MNF2009) Abstract: A simple 1-D model is presented to study the effects of the wall heat flux, location of the nucleation site, channel dimensions and fluid properties on the pressure fluctuations caused by confined bubble growth in rectangular microchannels, for zero upstream compressibility. A simple isothermal compressibility model is then used to study the effects of the initial volume of non-condensable gas trapped in the upstream plenum, initial inlet velocity and nucleation site location on local pressure fluctuations and transient flow reversal. Both acceleration pressure drop and viscous pressure drop are considered. Description: This paper was presented at the 2nd Micro and Nano Flows Conference (MNF2009), which was held at Brunel University, West London, UK. The conference was organised by Brunel University and supported by the Institution of Mechanical Engineers, IPEM, the Italian Union of Thermofluid dynamics, the Process Intensification Network, HEXAG - the Heat Exchange Action Group and the Institute of Mathematics and its Applications.

2009-01-01T00:00:00Z Pontrelli, G König, CS Collins, MW Long, Q Succi, S 2nd Micro and Nano Flows Conference (MNF2009) http://bura.brunel.ac.uk/handle/2438/6950 2012-10-12T09:22:31Z 2009-01-01T00:00:00Z

Title: Modelling wall shear stress in small arteries using LBM and FVM Authors: Pontrelli, G; König, CS; Collins, MW; Long, Q; Succi, S; 2nd Micro and Nano Flows Conference (MNF2009) Abstract: In this study a finite-volume discretisation of a Lattice Boltzmann equation over unstructured grids is presented. The new scheme is based on the idea of placing the unknown fields at the nodes of the mesh and evolve them based on the fluxes crossing the surfaces of the corresponding control volumes. The method, named unstructured Lattice Boltzmann equation (ULBE) is compared with the classical finite volume method (FVM) and is applied here to the problem of blood flow over the endothelium in small arteries. The study shows a significant variation and a high sensitivity of wall shear stress to the endothelium corrugation degree. Description: This paper was presented at the 2nd Micro and Nano Flows Conference (MNF2009), which was held at Brunel University, West London, UK. The conference was organised by Brunel University and supported by the Institution of Mechanical Engineers, IPEM, the Italian Union of Thermofluid dynamics, the Process Intensification Network, HEXAG - the Heat Exchange Action Group and the Institute of Mathematics and its Applications.

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