Research News
Hybrid rocket with ED nozzle tested
A team of engineers last month conducted a number of performance tests of their experimental hybrid rocket engine, called Firecrest.
The whole article can be found here.
07-June-2010
Research paper named the highlight of 2009 by leading nanotechnology journal
A collaborative research paper has been named as one of the highlights of 2009 by leading journal Nanotechnology.
Nanotechnology is published by the Institute of Physics (IoP) and the paper, which is ranked among the top eight papers in the Materials category, is entitled Effective elastic mechanical properties of single layer graphene sheets.
The paper is co-authored by Dr Fabrizio Scarpa of the University of Bristol's Department of Aerospace Engineering and Dr A Srikantha Phani of the University of British Columbia's Department of Mechanical Engineering.
The team's work focuses on the elastic moduli, and other effective mechanical parameters, of single layer graphene sheets (a one-atom-thick planar sheet of sp²-bonded carbon atoms, densely packed in a honeycomb crystal lattice), which have been a subject of intensive research in recent years.
In their paper, the team propose truss-type analytical models and an approach based on cellular material mechanics theory, to describe the in-plane linear elastic properties of the single layer graphene sheets.
The team's work ultimately aims to understand the mechanical properties of graphene, a fundamental building block of many carbon-based nanostructures such as carbon nanotubes. This understanding will enable designing nanostructures and devices with superior strength, stiffness, and performance.
Professor Adhikari said: "We are pleased and honoured to have our work on single layer graphene sheets recognised as a research highlight in such a prestigious journal.
"Since the publication of this work in Nanotechnology in 2009, we have extended this approach to the bending of single layer graphene sheets, which was also published in Nanotechnology, and bi-layer graphene sheets, which was published in Physics Letters. In the near future, we will consider graphene based nano-sensors and devices."
Nanotechnology’s highlights of 2009.
16-April-10
ACCIS News
University of Bristol (Advanced Composites Centre for Innovation and Science) and University of Bath have won a £1.4M four-year research award from EPSRC with Airbus and GKN support to create new capability to improve the structural efficiency of laminated carbon fibre composites. It will reduce weight and production cost by at least 10% compared with existing stiffened panels made from pre-impregnated material. The key innovation of the project will be to exploit state-of-the-art manufacturing, Variable Angle Tow (VAT) placement (where stiff carbon fibres are steered along curves to maximize structural performance). Ongoing studies suggest that such savings are achievable for standard test specimens (coupons) but new understanding is required to fully characterise structural and material behaviour from the full component level down to individual lamina and their interfaces. The entire structural system including material, geometrical and manufacturing parameters will be optimised. The extra design freedoms, created by curved fibre trajectories, provide scope for pushing back the envelope of structural efficiency. The team's preliminary VAT results indicate the prospect of developing buckle-free structures, reducing the need for stiffeners, with associated substantial cost and weight savings. Moreover, the specific manufacturing capability to produce variable angle fibres is unique to the UK, having been modified from an embroidery machine, using dry fibres rather than pre-impregnated material.
For further details of ABBSTRACT2, please contact Prof. Paul Weaver (Email) and Dr Richard Butler (Email).
Above: Illustration of curved fibres in a transverse embroidered VAT ply. A longitudinal ply (not shown) has significant 0o orientations, close to, and parallel to the long sides and -30.4o in the centre.
06-Jan-10
In the news: Albatross UAV
Department researcher Markus Deittert has been featured in New Scientist magazine for his research on "Dynamic Soaring" for Unmanned Air Vehicles (UAVs). Inspired by Albatross flight, the method involves low-flying, fast turns to extract energy from the wind gradient close to a water surface. Potentially, a small UAV could use the technique for very long endurance flight with minimal engine use, or even none at all.
The work was done as part of Markus' PhD at the Bristol Robotics Lab, supervised by Tony Pipe (BRL), Chris Toomer (UWE) and Arthur Richards. More information can be found in "Engineless Unmanned Aerial Vehicle Propulsion by Dynamic Soaring" in September's AIAA Journal of Guidance, Control and Dynamics.
13-Oct-09
New Partnership to Advance Wind-Power Technology
The University of Bristol have established a partnership with Vestas Wind Systems, a world leading provider of wind power and services, to develop composites technology for future products.
23-Jul-09
Prize-winning Paper
Dr Michael Steeden, President of the Royal Aeronautical Society, presenting the Bronze award certificate to PhD student, Christophe Thill (Paul Weaver looking on), for "Morphing Skins" published in The Aeronautical Journal 2008. The award was given at RAeSoc headquarters in London on occasion of the Sopwith Lecture, 9th July 2009. The co-authors Ian Bond, Kevin Potter and Julie Etches unfortunately could not be present at the ceremony. The paper can be found from: (Thill C. Etches J. A , Bond I. P, Potter, K and Weaver, P. M. "Morphing Skins-A Review", The Aeronautical Journal, Vol 1129 , pp117-129, 2008).
15-Jul-09
The Rocket that thinks it's a Jet
Dr Neil Taylor is to take part in research which is to build on the extensive successes of the the STERN project.
Dr Neil Taylor in the University’s Department of Aerospace Engineering, will explore advanced exhaust nozzles that can adapt to the ambient atmospheric pressure. This follows on from the successful STERN (Static Test of ED Rocket Nozzle) test rocket programme that was conducted last year. As part of the ESA contract a new water-cooled chamber will be constructed and test fired.
19-Feb-09
EPSRC Centre for Doctoral Training award for Department of Aerospace Engineering ACCIS Centre
The Advanced Composites Centre for Innovation and Science, based in the Department of Aerospace Engineering, will help provide the necessary skill base and expertise to inspire the next generation of scientists and engineers. The rapidly growing use of composites in aerospace and renewable energy requires a technological transformation for the UK to maintain a lead. This centre will encompass all aspects of the materials science and engineering of composite materials.
05-Dec-08
Self-repairing Aircraft could Revolutionise Aviation Safety
A new technique that mimics healing processes found in nature could enable damaged aircraft to mend themselves automatically, even during a flight.
As well as the obvious safety benefits, this breakthrough, developed by aerospace engineers at Bristol University, could make it possible to design lighter aeroplanes in future. This would lead to fuel savings, cutting costs for airlines and passengers and reducing carbon emissions.
20-May-08
Morphing Aircraft Research featured in NewScientist
Researchers at Bristol University, UK, are developing an aircraft with an "elbow" in each wing that can tilt the wing tips up or down. That changes the wing's aerodynamics, and allows the aircraft to be manoeuvred without using traditional control surfaces like elevators and ailerons.
01-Apr-08
First Firing of STERN Rocket Engine
A team of engineers from Bristol University has conducted the first firing of the STERN rocket motor. Rocket engines equipped with the STERN (Static Test Expansion/Deflection Rocket Nozzle) rocket motor should benefit from increased performance in flight and achieving the firing test is a major step forward in a long term programme to understand the way these more complex nozzles work.
The STERN project is led by Dr Neil Taylor, Lecturer in Aerodynamics in the Department of Aerospace Engineering at the University of Bristol.
- "This test is a major step forward and should give us a much better insight into what is going on inside the engine."
Dr Neil Taylor
26-Mar-08
New web pages for the Multifunctional Composites Group
A series of new web pages have been developed to highlight the work of the Multifunctional Composites Group - part of the Structures and Materials Research Group. The principal aim of their work is to develop, characterise and optimise a variety of innovative and ingenious approaches which provide functionality to fibre reinforced polymer composite materials and take them beyond their current structural role. This opens up a whole new area of research for the UK.
Functionalities such as self-healing, novel fibre shape, and magnetically active composites are currently being developed.Other exciting areas of multifunctionality being considered include self-cooling, triboluminescence and magnetostriction.
The group is also actively involved in a wider effort to develop technologies for 'morphing' structures.
01-Oct-06
Final year student Alison Drury has been working on:- Investigation of tensile properties of shaped fibres
The Aerospace Engineering Department has developed a technique to create glass fibre reinforcement with a shaped cross-section, which improves the through-thickness properties of reinforced plastics. In this case the fibre is a flower shape with six petals. Having seen improvements in through-thickness performance of the composite it was necessary to assess the properties of single fibres. Three properties were chosen for investigation; tension, compression, and interfacial shear strengths. A simple test was devised to assess each of these in turn. The tensile test consisted of measuring the force to fracture single fibres. To measure interfacial shear strength a pull-out test was devised, where the force required to remove a single fibre from a small drop of resin was measured. Axially loading a small bundle of fibres in compression provided an indication of compression strength. Initial results have shown shaped fibres to offer improved pull-out load and compression strength with a marginal reduction in tensile strength.
01-Apr-04
Final year students Neil Russell and Chris Rushworth have been working on:- Development of an Integrated Simulation Environment for both Manned and UnManned Air Vehicles
There is currently a great deal of research surrounding the development of uninhabited combat aerial vehicles (UCAVs). A current field of interest is the control of autonomous UCAVs and the type of interaction that will exist in the field of conflict. The objective of this research project was to assess the ability of a pilot to control an F16 whilst simultaneously issuing commands to a fleet of UCAV wingmen.
The project has involved developing a realistic simulation of an F16 using the faculty’s six degree-of-freedom, single-seat motion pod. The simulator also requires that the pilot interact with a number of UCAVs in the world model, by issuing tasks and responding to their feedback.
A series of test have been created in the environment which assess how well a pilot has performed. The tests set the pilot the task of pursuing another F16 throughout the world while instructing the pilot to give orders to each of the UCAVs. Various factors are considered when evaluating the pilot’s performance: time to issue each UCAV command, deviation from the path of the aircraft being pursued, complexity of the path etc.
01-Apr-04
PhD student Ben Green has been working on:- Scaling effects in notched composites
Composite materials such as carbon fibre are increasingly being used in large primary aircraft structures.
Designers need to be able to extrapolate laboratory test coupon results reliably to full-scale components.
This is made difficult by the existence of a size effect in materials, whereby the strength of a specimen decreases as size increases.
Current research is focusing on developing methodologies to aid in the design of such components by quantifying the size effect, and understanding the mechanisms through which it occurs.
01-Apr-02