Bristol and Bath Science Park

About: Bristol and Bath Science Park is a education organization based out in Bristol, United Kingdom. It is known for research contribution in the topics: Composite number & Heat exchanger. The organization has 22 authors who have published 26 publications receiving 476 citations.

Accuracy of the actuator disc-RANS approach for predicting the performance and wake of tidal turbines.

Abstract: The actuator disc-RANS model has widely been used in wind and tidal energy to predict the wake of a horizontal axis turbine. The model is appropriate where large-scale effects of the turbine on a flow are of interest, for example, when considering environmental impacts, or arrays of devices. The accuracy of the model for modelling the wake of tidal stream turbines has not been demonstrated, and flow predictions presented in the literature for similar modelled scenarios vary significantly. This paper compares the results of the actuator disc-RANS model, where the turbine forces have been derived using a blade-element approach, to experimental data measured in the wake of a scaled turbine. It also compares the results with those of a simpler uniform actuator disc model. The comparisons show that the model is accurate and can predict up to 94 per cent of the variation in the experimental velocity data measured on the centreline of the wake, therefore demonstrating that the actuator disc-RANS model is an accurate approach for modelling a turbine wake, and a conservative approach to predict performance and loads. It can therefore be applied to similar scenarios with confidence.

The bending and failure of sandwich structures with auxetic gradient cellular cores

Abstract: We describe the bending and failure behaviour of polymorphic honeycomb topologies consisting of gradient variations of the horizontal rib length and cell internal across the surface of the cellular structures. The novel cores were used to manufacture sandwich beams subjected to three-point bending tests. Full-scale nonlinear Finite Element models were also developed to simulate the flexural and failure behaviour of the sandwich structures. Good agreement was observed between the experimental and FE model results. And the validated numerical model was then used to perform a parametric analysis on the influence of the gradient core geometry over the mechanical performance of the structures. It was found that the aspect ratio and the extent of gradient (i.e. the horizontal rib length growth rate or the internal angle increment) have a significant influence on the flexural properties of the sandwich panels with angle gradient cores.

Manufacturing of composite parts reinforced through-thickness by tufting

Abstract: The paper aims at providing practical guidelines for the manufacture of composite parts reinforced by tufting. The need for through-thickness reinforcement of high performance carbon fibre composite structures is reviewed and various options are presented. The tufting process is described in detail and relevant aspects of the technology are analysed such as: equipment configuration and setup, latest advances in tooling, thread selection, preform supporting systems and choice of ancillary materials. Effects of the process parameters on the preform fibre architecture and on the meso-structure of the reinforced component are discussed. Special emphasis is given to the different options available in terms of tuft insertion and loops management.Potential fields of application of the technology are investigated as well as the limitations of its applicability in relation to preform nature and geometry. Critical issues which may arise during the manufacturing process concerning thread insertion, loops formation, alteration to the fabric fibres layout or local volume fraction are identified. Tufting, as a process to manufacture reinforced composite structures, is described.Relevant aspects of the tufting technology are presented and analysed.Critical issues which may arise during the tufting process are identified/addressed.The effect of process parameters on the meso-structure of the component is discussed.Current and potential fields of application of the technology are investigated.The limitations of the applicability of tufting are discussed.