Aug 22

Improving Fish passage on the Adur

Improving fish passage on the Adur by Rachel Paget

Ouse and Adur River Trust Newsletter. Summer 2018. https://oart.org.uk/wp-content/uploads/2018/10/OART-11-Summer-2018-E-Newsletter-1.pdf

OART have installed a new fish pass at Haterell’s Bridge, removing a significant barrier to fish passage on the Western arm of the River Adur and facilitating increased, multi-species, fish movement through an additional 2.2km of river. Read the rest of this entry »

Aug 21

Understanding the charge storage mechanism of conductive polymers as hybrid battery-capacitor materials in ionic liquids by in situ atomic force microscopy and electrochemical quartz crystal microbalance studies

research Article

Theresa Schoetz, Mario Kurniawan,  Michael Stich,  Ralf Peipmann,
Igor Efimov, Adriana Ispas, Andreas Bund,  Carlos Ponce de Leon
and Mikito Uedad

First published in Journal of Materials Chemistry A for Royal Society of Chemistry: 21st August 2018

DOI: 10.1039/c8ta06757k

Safe and sustainable energy storage systems with the ability to perform efficiently during large numbers of charge/discharge cycles with minimum degradation define the main objective of near future energy storage
technologies. Read the rest of this entry »

Jul 06

Potential of wireless power transfer for dynamic charging of electric vehicles

Luke Hutchinson, Dr Ben Waterson, Bani Anvari and Denis Naberezhnykh

IET Intelligent Transport Systems

1751-956X

Scopus rating (2019): CiteScore 3.8 SJR 0.627 SNIP 1.468

10.1049/iet-its.2018.5221

Abstract

Wireless Power Transfer (WPT) offers a viable means of charging Electric Vehicles (EV)’s whilst in a dynamic state (DWPT), mitigating issues concerning vehicle range, the size of on-board energy storage and the network distribution of static based charging systems. Such Charge While Driving (CWD) technology has the capability to accelerate EV market penetration through increasing user convenience, reducing EV costs and increasing driving range indefinitely, dependent upon sufficient charging infrastructure. This paper reviews current traction battery technologies, conductive and inductive charging processes, influential parameters specific to the dynamic charging state as well as highlighting notable work undertaken within the field of WPT charging systems. DWPT system requirements, specific to the driver, vehicle and infrastructure interaction environment are summarised and international standards highlighted in order to acknowledge the work that must be done within this area. It is important to recognise that the gap is not currently technological; instead, it is an implementation issue. Without the necessary standardisation, system architectures cannot be developed and implemented without fear of interoperability issues between countries or indeed systems. For successful deployment, the technologies impact should be maximised with the minimum quantity of infrastructure and technology use, deployment scenarios and locations are discussed that have the potential to bring this to fruition.

May 18

Endurance testing of the STAR additively manufactured resistojet

Matthew Robinson, Dr Angelo Grubisic, Dr Federico Romei and Christopher Ogunlesi

Space Propulsion 2018

14/05/18 → 18/05/18

Seville, Spain

Introduction
The potential of an all-electric spacecraft is enhanced by the possibility of a single integrated propellant supply. A common propellant choice is xenon. This creates new performance demands for a high-temperature xenon resistojet, elevating the hot gas temperature requirement to a minimum of 2400 K to achieve 80 s ISP, or 3300 K for 95 s, compared to the current state of the art at 48 s [1]. This represents significant materials and design challenges – beyond the flow kinetics, a major practical challenge facing the high-temperature resistojet technology is retaining structural integrity at the very high operating temperatures, whilst minimizing viscous and radiative heat losses. The University of Southampton has identified a technical solution to this problem and advanced thermofluid multiphysics simulations are currently ongoing as part of a current collaboration with Surrey Satellite Technology Limited (SSTL), alongside an iterative design process and experimental campaign to reach the performance possible from a high-temperature resistojet.

Discussion
This paper presents an experimental campaign on a novel high-temperature resistojet heat exchanger manufactured through selective laser melting (SLM) of 316L stainless steel, to validate the manufacturing approach. The heat exchanger is produced as a single-piece component including an integrated convergent-divergent nozzle, significantly reducing the time and cost of manufacture.

Environmental and endurance testing will be performed on the component, including: thermal cycle life testing; vibration testing; and cleanliness testing. This will allow a comparison between conventionally, and additively manufactured resistojet heat exchangers.

These tests will be combined with a novel process of high-resolution micro-Computed Tomography (μ-CT), applied as a tool for volumetric non-destructive inspection, since the complex geometry of the thruster does not allow internal inspection. The results in this paper will be used in an iterative process to further improve the design of the STAR (Super-high Temperature Additive-manufactured Resistojet). The paper will also include the testing of Inconel and refractory alloys via the same methods.

Conclusion
A high-temperature xenon resistojet is an enabling technology for an all-electric spacecraft. This paper presents an experimental campaign on additive-manufactured prototypes as a precursor to the development of the refractory metal high-temperature thruster. The data presented will be used to validate the design and manufacturing approach, and inform the next stage of development of the STAR.

 

May 18

High performance resistojet thruster: STAR Status Update

Dr Federico Romei, Dr Angelo Grubisic, Matthew Robinson and Dave Gibbon

Space Propulsion 2018

14/05/18 → 18/05/18

Seville, Spain

Abstract

This paper presents the performance testing of the Super-high Temperature Additive Resistojet (STAR) prototype, the first additively manufactured resistojet thruster with a novel monolithic design of heat exchanger. In this paper, operation of the concept was demonstrated at the operational temperature limits of the prototype material. In hot gas mode, the prototype developed 80s specific impulse with argon gas, with a calculated stagnation temperature between 380°C and 500°C at the inlet of the nozzle. The paper proves the feasibility of operation of a concentric thin walled monolithic recirculating resistojet manufactured via selective laser melting.

May 18

Novel non-destructive inspection of the STAR additively manufactured resistojet

Christopher Ogunlesi, Dr Angelo Grubisic, Dr Federico Romei and Matthew Robinson

Space Propulsion 2018

14/05/18 → 18/05/18

Seville, Spain

Abstract

Surrey Satellite Technology Limited (SSTL) has used a low power hot gas system known as a resistojet since 2002, which uses either Butane or Xenon as propellant. This system has flown on 20 spacecraft including the European GPS Galileo Testbed GIOVE-A validation satellite. This low cost and relatively low temperature resistojet significantly improves the performance of traditional cold gas propulsion systems. A collaborative development programme between the University of Southampton and Surrey Satellite Technologies Limited (SSTL) is currently proceeding to develop a Super-high Temperature Additive-manufactured Resistojet (STAR), which nearly doubles current ISP performance. The STAR is designed to increase the stagnation temperature of the propellant to approximately 3,000 K. Multiphysics models predict the total thruster efficiency to be in the range of 65-90%, resulting in an ISP for xenon propellant above 80s. The intricate design of the resistojet, as well as the high temperatures involved present significant design, manufacturing and materials challenges. The University of Southampton have identified novel solutions to these issues in a research programme that includes electrothermal simulations, additive manufacturing, performance testing and ultimately the validation of a breadboard model thruster.

Discussion

The paper presents the design, manufacturing and postproduction analysis of a novel high-temperature spacecraft resistojet heat exchanger manufactured through selective laser melting to validate the manufacturing approach. The work includes the analysis of critical features of a heat exchanger with integrated converging-diverging nozzle as a single piece element. The metrology of the component is investigated using optical analysis and profilometry to verify the integrity of components. A novel process of high-resolution micro-Computed Tomography (CT) is applied as a tool for volumetric non-destructive inspection and conformity since the complex geometry of the thruster does not allow internal examination.

The CT volume data is utilised to determine a surface mesh on which a novel performed coordinate measurement technique is applied for nominal/actual comparison and wall thickness analysis. A thin-wall concentric tubular heat exchanger design is determined to meet dimensional accuracy requirements through nominal/actual comparison analysis.

Conclusion

The work indicates the production of fine structures with feature sizes below 200 μm in 316L stainless via selective laser melting is feasible and opens up new possibilities for the future developments in multiple industries. The paper will also include the non-destructive inspection of Inconel and refractory alloys via the same method.

May 15

Immediate impact of a hurricane on the structure of a tropical butterfly community: Impact of hurricane on butterflies

Dr Frances Mullany, Georgina Hollands and Dr Jake Snaddon

Biotropica volume 50

First published 15.05.2018

10.1111/btp.12549

Abstract

More intense and frequent hurricanes may lead to long-lasting effects to tropical ecosystems. Here we describe the immediate impact on the butterfly community of a lowland forest in Belize, following Hurricane Earl. Species richness and abundance increased post-hurricane, likely driven by convergence of the organisation between the canopy and understory communities.

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