Analysis of heat dissipation from railway and automotive friction brakes

The thesis presents research into the understanding and improvement of heat dissipation from friction brakes. The investigations involved two brake types, considered to be the most thermally loaded and therefore most challenging; axle mounted high speed railway and commercial vehicle disc brakes. All three modes of heat transfer (conduction, convection and radiation) and airflow characteristics have been analysed experimentally and theoretically in order to increase the understanding of heat dissipation. Despite the very practical aspects of this research, a 'generic heat transfer approach' was applied, enabling wider engineering applications of the results. Experimental analyses conducted on a specially developed Spin Rig allowed measurements of cooling and airflow characteristics for different designs. Methodologies have been developed to determine thermal contact resistance, heat transfer coefficients, emissivity and aerodynamic (pumping) losses. Established values and relationships compared very favourably with theoretical work. Analytical, FE and CFD analyses were employed to further investigate design variations and perform sensitivity studies. Inertia dynamometer route simulations provided disc temperatures for validation of the overall work. Recommendations have been made for optimising heat dissipation, by proposing practically acceptable and economically viable design solutions. A proposed ventilated disc design efficiency ratio allows large, high speed ventilated disc designs, to be efficiently and accurately evaluated and compared, providing a valuable disc design optimisation tool. The determination of the methodologies, parameters and functions defining cooling characteristics, enable heat dissipation to be predicted confidently and accurately for brakes and other engineering assemblies at early design stages.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Multi-scale, electro-thermal model of NMC battery cell

Battery models often either fail to deliver a complete picture of the physical phenomena occurring in the cell or fail to minimize computational effort. So far, the demand for a detailed internal thermal model of battery cells with a reasonable computation time has remained unanswered. This paper addresses such question introducing a multi-domain model whose accuracy makes it suitable for thermal management system development, at a lower computational cost than competing models. The approach features an equivalent circuit parameter model with chemistry-based parameters coupled with an internal heat transfer model. The internal heat transfer model includes different sections of the cell, addressing the anisotropy and the temperature-dependence of physical properties. Material properties are partly based on manufacturer's data sheet, partly taken from literature. The development software platform enables a sensible reduction of computational effort with respect to traditional modeling techniques. Results were validated against an aggressive current at different temperatures and against current profiles obtained from two different drive cycles at different ambient temperature. The model proves to be very good in terms of accuracy

Video Re-sampling and Content Re-targeting for Realistic Driving Incident Simulation

We present a video generation and visualization system for integration into a driving incident simulator. We combine the use of video re-sampling, target tracking and object segmentation for content re-targeting to generate realistic video content that can be adapted on demand, based upon simulator inputs to generate a range of driver incident test scenario

The testing of two methods for the moisture measurement of building fabrics via comparisons with data from an X-ray system

The measurement of moisture in building fabrics has been of interest for many years due to potentially devastating consequences of moisture problems within buildings. A range of potential techniques are available with which to measure the moisture content of building fabrics in situ and this paper focuses on two techniques which offer the potential for some significant advantages over approaches: (1) thermal dual-probe and (2) time domain reflectometry. The two approaches have been tested against measurements of moisture content using a laboratory-based X-ray measurement facility. As a result of the work that has been undertaken, the authors are very confident that the two measurement techniques are indeed applicable to typical building fabrics