Impact case study database

The Joining Technology Research Centre at Oxford Brookes University has been the source of invaluable expertise for YASA Motors. Two successful KTPs led to a significant increase in the technical and commercial capabilities of YASA and further contribution towards a lower carbon economy.

Currently, most of YASAs production of motors and controllers resides in the automotive sector, enabling automotive manufacturers to meet increasingly stringent emissions targets whilst delivering exciting driving experiences. In addition to automotive applications, YASA motors are used in defence, marine and aerospace sectors where high power density and torque density are critical. All these markets demand highly reliable, lightweight and robust motors, given the extreme environments these types of vehicles operate within. In 2018, YASA officially opened its 100,000 unit motor production facility. The Business Secretary, Greg Clark MP, who delivered the opening address said, “ YASA is a brilliant example of what can be achieved when government, academia and industry come together to turn the best ideas from the best minds into scale-up companies” [5.1]. YASA is now well-placed to capture significant market share within these sectors too and a significant aspect of this is down to the robust bonding technologies and company knowledge gained through the unique, on-going, relationship fostered between Oxford Brookes University and YASA.

Initially, the partnership was sought to provide the capability to make high torque, low mass motors using injection moulding polymers with adhesive/composite bonds. Prior to the KTP project with JTRC, YASA lacked adhesive joining expertise, particularly relating to the design of interfaces and bonding of composite parts to proposed low surface energy polymers, as well as expertise in choosing or designing test methods suitable for testing such bonds against environmental and mechanical stresses, all needed for scaling to mass manufacture [5.5].

With the first KTP focused primarily on production issues, there have been several significant impacts on the business. Dr Tim Woolmer, Founder and CTO, YASA Limited remarked, “ The combination of expertise and equipment had attracted us to the KTP – but everyone here has been blown away by the results” [5.2]. These main technological impacts were first introduced in 2013, where the company at the time recorded a revenue of GBP1,600,000. Issues directly linked to the bonding process were resolved, which meant defect-rates had fallen by a factor of 100, saving almost GBP100,000 in avoidance of motor durability failures. The KTP Associate Jonny Biddulph conducted trials of new technology on injection moulded stator plates, where the outcome was a part-cost reduced from GBP177 to GBP7. With two of these parts included in every motor this represented a significant saving (GBP1,140,000 for 3,000 motors) and allowed the joining of neighbouring parts by laser welding, further increasing manufacturing speed. The manufacturing process time reduced from 7 days to 2 days, potentially saving GBP16,650,000 (reduced assembly time savings GBP18.50/hour production cost, based on predicted 90,000hours saved three years after completion of KTP) [5.3]. From Oxford Brookes University’s first involvement with YASA in 2011, the company grew from 12 to ~150 employees in 2020, with a recorded revenue of GBP7,600,000 in 2018 [5.4]. This growth has been necessary to extend production rates from less than 50 motors per annum to a high volume capability of 100,000 units per annum [5.1]. This capability would not be possible without the key technology to deliver high-volume over-moulded bonded stator plates.

This KTP has subsequently proven instrumental to sustaining the growth of YASA Motors in the areas of materials and bonding technologies. On the back of demonstrating robust bonding procedures, the motors were adopted for the Jaguar C-X75 supercar, dubbed ‘ the most technologically advanced road car ever conceived’, and on the strength of this YASA were shortlisted for the Society of Motor Manufactures and Traders (SMMT) Award for Automotive Innovation [5.6]. Other high-end sports cars have since adopted the technology, proving its capabilities in demanding environments. For example, the [text removed for publication] uses three YASA motors and, according to [text removed for publication], delivers the fastest accelerating, most powerful production car ever. [text removed for publication] commented: “ YASA’s motors are extremely power dense, making them the key-ingredient for the direct drive system. The torque capability of the YASA motors combined with our world-leading engineering expertise has given the [text removed for publication] an acceleration capability that is second to none” [5.7]. [text removed for publication], like many other OEMs are now also heavily investing in hybrid and electric vehicles, and have integrated seven P400 motors in their new [text removed for publication] supercar [5.8]. YASA electric motors also power [text removed for publication] first hybrid series production sports car, the [text removed for publication]. YASA have been working closely with [text removed for publication], developing a custom version of its electric motor that meets [text removed for publication] demanding performance specifications. The [text removed for publication] was launched by [text removed for publication] on 29 May 2019, in [text removed for publication] [5.9]. Such projects are often the proving grounds for the adoption of new technologies into more mainstream vehicles.

As a direct result of the KTP and the strategy to develop high volume production motors, three key international patents were filed by YASA and the Oxford Brookes University KTP research assistant. Patent EP3044854: Stator Plate Over-moulding (2014) involved placing a resin membrane into a mould of an injection-moulding machine and injection moulding a set of reinforcing features onto the membrane using a bondable thermoplastic polymer [5.10]. Patent EP3044849: Pole Piece Bonding (2014) uses similar technology for bonding the pole pieces using a flexible resin membrane. The resin membrane, which may contain woven glass fibre reinforcement, may be an engineering polymer material (e.g. PPA, PEEK, PPS, ABS, PA) wherein reinforcement inhibits the stator bars from pushing through the membrane. An additional thermoplastic polymer resin is used for supplementary bonding injection moulded reinforcing features [5.11]. Due to the high rotational rotor speeds that generate large centripetal forces on the rotor stages, particularly on surface mounted magnets, any loss of magnet adhesion is a risk for this motor topology. In order to combat this issue a third Patent, EP2773023: Axial Flux Motor (2013), was filed. It introduced a composite rotor for the axial flux motor, wherein the rotor holds permanent magnets circumferentially spaced around the rotor. An over-winding of strands of reinforcement material are toroidally-wound over the rotor and magnets. The strands help strengthen the rotor and provide a lightweight and high performance product [5.12]. Together, the technology behind these patents helped deliver the third generation P400 motors.

The technical transition towards the launch of the P400 R from earlier models is consistent with the dramatic increase in demand for low carbon emission technologies, driven by legislation and motivated by climate change. The P400 R Series is now manufactured using advanced materials and proprietary construction techniques that enable high-volume production with significant customer cost benefits. An important innovation of the P400 R Series is the use of an engineering polymer housing for the motor stator, in place of the aluminium housing used in earlier models. The performance of engineered polymer material is strong, highly durable and lightweight, and is already in common use in volume automotive applications (not motors). Importantly, the materials used in the P400 R Series reduce both material cost and assembly time, the direct legacy of the first KTP. The low weight of the new polymer housing also helps to improve the overall motor performance [5.13]. Lightweighting also has secondary benefits that include reduced wear on components, reduced maintenance and an extension of service life.

Oxford Brookes University’s contribution to the development of these electric motors for mass production puts UK industry at a significant advantage to deliver on Government targets for total electrification of transport by 2050. An example of the broader reach of this technology includes the application of electric motors in the [text removed for publication] hovercraft, as bow thrusters to provide reversible sideways thrust for craft manoeuvring at low speed. With minimal modification, two YASA P400 motors were incorporated into the design of the hovercraft. The principal benefit of using YASA electric motors was that two of the four diesel engines could be eliminated from the design. This reduced the noise levels from the engines significantly, without adversely affecting the reliability of the craft [5.14]. Likewise, [text removed for publication] has completed testing of the ground-breaking technology that will power the world’s fastest all-electric plane. The plane is part of a [text removed for publication] initiative called ACCEL, short for ‘Accelerating the Electrification of Flight’. The ACCEL project team includes YASA as key partners along with the aviation start-up Electroflight [5.15].

The knowledge gained from the underpinning work with OBU to enable lightweight EPMs to be used effectively, has greatly assisted YASA to supply motors to production electric vehicles, owned by mainstream OEMs [5.16]. OEMs that have been associated with YASA products include [text removed for publication] [5.1]. Without robust assembly technologies and the ability to bond a multitude of different lightweight materials, the YASA motor could not supply a volume production unit of the highest quality demanded by OEMs. Indeed, without high quality bonding methods and procedures, the motor could not deliver on the performance required for today’s transport requirements, let alone meet the future global transportation needs.

In 2016 the World Health Organization (WHO) estimated that more than 4 million people die prematurely every year as a result of exposure to PM. Road transportation is responsible for the release of up to 20% of atmospheric carbon matter, or soot. Modern GDI engines are especially problematic because they produce large numbers of ultra-fine particles.

Soot formation in GDI engines is normally associated with imperfect mixing between air and fuel, and with liquid film of fuel being deposited on piston and cylinder walls during fuel injection. Exhaust filters are currently used by most manufacturers to comply with EU6b and US emission regulations. However, the most dangerous particles with a size of less than 23 Nm are not currently regulated, and cannot be removed effectively by filtration. As the forthcoming EU7 regulations will impose much stricter limits on PN emissions, for the GDI engine to remain viable for use in passenger vehicles, improved understanding and disruptive solutions are essential.

The impact generated by the OBU team as part of the DynAMO project has four main strands:

• It has fundamentally transformed Ford’s knowledge around the mechanisms of PM formation and the link with limiting piston temperatures. This is playing a significant part in Ford’s planning to comply with the new, stricter emission regulations.

• It has enabled Ford to begin the shift to less costly digital engineering tools (to replace hardware testing), as part of future engine development.

• It is enabling Siemens DISW, another DynAMO partner, to integrate the 3D CFD modelling approaches developed by OBU into beta versions of its market-leading software, STAR-CD and STAR-CCM+.

• It is enabling Ricardo, another DynAMO partner, to integrate significantly improved turbulence and combustion models into its 0D/1D WAVE software, and these are planned for release as future add-ons/options.

Ford had a market share of automotive sales of approximately 14% worldwide and 10% in the UK in 2019. New knowledge and tools being established and embedded within the engineering teams on the Ford UK, Dunton Campus (and extended to Ford North America) are key to Ford’s future economic, environmental and societal impact, globally. This is as a direct result of OBU’s CFD modelling work.

Ford’s technical expert for the DynAMO project explains in a support letter how the OBU modelling work has ‘completely revolutionised’ the understanding of particulate formation mechanisms within Ford. The theory advanced by OBU ‘was a revelation … For the first time I could appreciate how … to explain transient PN behaviour’. Importantly, ‘this new knowledge may assist Ford, and other automotive OEMs, to comply with the increasingly stringent legal PN emission regulations, ensuring the sustainability of GDI engine technology, even in hybrid applications’ [S1]. A key factor in this is understanding the need to maintain high-enough piston temperatures at all stages of vehicle operation, which could ensure compliance with EU6 limits (6.0E+11 particle/km), and possibly beyond, without the use of costly filtering devices.

A further support letter produced by Ford echoes the first one, confirming current as well as future impacts generated by the OBU work, in terms of new understanding and development opportunities: ‘The concepts and theories proposed by OBU have effectively changed the perception of these issues [the mechanisms of PM formation, and the influence of piston temperature on liquid film formation] within the Ford Technical Team, and open new areas of opportunity, including new piston design and novel calibration approaches such as the piston cooling strategy, which directly consider the trade-off between component durability and PM emissions ’ [S2]. The OBU team proposed a dual-fuel engine simulation that offers unprecedented accuracy. This enables reliable prediction of fuel distribution and liquid film, and how these start forming soot during combustion. The Ford support letter remarks on how the OBU work is contributing to the present shift in practice within the organisation, which is the second strand of impact claimed in this case study: ‘The modelling work carried out by the team at OBU has been … impactful to Ford especially. Compared to common approaches … at Ford, the OBU modelling framework offers increased robustness, accuracy and functionality, and as such will assist the gradual but necessary transition … to cost-effective digital engineering … The tools are being established … within the engineering teams on the Ford Dunton UK Campus and extended to Ford North America, where development of new gasoline and hybrid powertrain platforms will continue to be strong for the foreseeable future’ [S2].

A further strand of OBU’s impact relates to development by Siemens DISW, another DynAMO partner, which has a major share in the 3D CFD engine modelling market. Siemens will be rolling out the novel modelling framework to the wider CFD user community. The director of powertrain at Siemens DISW gives evidence of the OBU impact, which improved both understanding and practice within the organisation: ‘To my knowledge, this is the most accurate GDI engine modelling framework available through a commercial CFD software platform. The methodologies proposed … are also of high significance to Siemens DISW because OBU unveiled shortcomings in the current offered … approach, which now Siemens DISW is addressing. The novel … methodologies will feed into future releases of … STAR-CD … and also support the new platform Simcenter STAR-CCM+ in-cylinder solution’ [S3]. The OBU work has so far directly contributed to three releases of the STAR-CD software, which now offers a direct calculation of engine charge homogeneity, improved numerical stability for the modelling of liquid film and improved calculations of PM characteristics. The DynAMO project also provided experimental data, acquired for, processed and validated through the OBU models, and this is acknowledged in a Siemens blog describing its latest release of in-cylinder combustion modelling in STAR-CCM+ [S5].

The models developed by OBU will be further integrated into the 0D-1D Ricardo WAVE platform. This has even more users than engine CFD software, which is mostly used by specialist departments. Ricardo’s technology manager (software) gives a clear indication of the impact of this work on the Ricardo organisation, through the release of add-ons for future software and therefore the ability to more accurately model the generation of PN emissions: ‘Oxford Brookes … have been able to identify flaws in the initial 0D turbulence model implementation … and validate the improved combustion model … The OBU team have proven to have a unique blend of excellent capability with relevant experience and the results of this work will be feeding into future releases of Ricardo WAVE via add-ons and best practice guidelines’ [S4].

Ford’s confidence in the direction indicated by OBU’s work also led to it investing £100,000 to significantly enhance the engine testing capabilities at OBU. OBU’s specific contribution to the DynAMO project has been fundamental in enabling one of the world’s biggest engine manufacturers to begin to successfully address the challenge of reducing PM in line with new EU regulations. It has also enabled leading software companies to create new products that may be transformative for their businesses. This paves the way for reducing the major health risk associated with PM in the future.

Sustainable personal travel solutions for individuals, families and business are a critical element of future transport strategies in the UK and internationally. SVEC’s cross-sector, multi-disciplinary, research into the economic, technical, social and environmental aspects of electric vehicles, including battery pack manufacture and recycling, have had significant impact on automotive manufacturers and those planning future transport policy. As noted by Andrew Smith MP in 2015, Higher Education Innovation Fund support was used to set up the Sustainable Vehicle Engineering Centre at Oxford Brookes University: “That has been used by BMW and all the major automotive companies in the development of electric vehicles. The university has just launched an innovative new undergraduate degree in business and automotive management, in partnership with BMW. That is university innovation in the lead in a crucial national industry" [5.1].

Impact on development of the BMWi3 and general market acceptance of EVs

The MINI E project was designed by BMW Group as a path-breaking field trial in the early days of electro-mobility. It aimed to gain insights into real life usage and customer expectations of Electric Vehicles (EVs) prior to any vehicles coming to market. There were six trials in total across Europe, Asia and the USA, and SVEC was the lead scientific partner in its UK trials (2009-11). Oxford City was an early major beneficiary of the electric vehicle trials, with around 80 public charging points installed or planned around the city. In 2019, Head of Government Affairs, BMW Group (UK) wrote to Professor Hutchinson, Head of SVEC, confirming that the company “ highly value the output of the research performed by your team at Oxford Brookes University, and the way in which it has benefitted all ‘BMW i” projects after the ‘MINI E’” [5.2]. Specifically, the BMW Group highlighted that the results of the MINI E UK project had direct influence on their electrification strategy, the developments of the BMW i3 and ultimately the MINI Electric, and helped to inform policy-making decisions as well as other EV market stakeholders [5.2].

SVEC’s key contribution to the MINI E UK project was the collation and analysis of vehicle energy use and electricity grid data, plus strategic market analysis, to inform BMW developments in battery management, optimised cabin heating, grid connectivity and business segments for future marketing policy. Furthermore, SVEC worked together with colleagues from the Department of Psychology (OBU) who analysed the social and psychological aspects of driving electric cars, over time. These findings helped to inform BMW’s vehicle cabin design and vehicle interfaces. It also allowed BMW Group to understand how drivers respond to electric cars in terms of expectations, behaviours and opinions. Head of Government Affairs, BMW Group (UK) stated: “…the results proved the vital role charging at home has as a key argument to win potential customers. This strongly shaped public decision making for charging infrastructure as well as BMW Group’s activities in offering installation services as a part of the vehicle purchase process. Results achieved by Oxford Brookes on the MINI E’s characteristics in respect to the enjoyment level in the strong dynamics of electric vehicles also strongly influenced the future BMW “i” strategy” [5.2]. OBU research findings were reviewed at project meetings and workshops in UK and Germany and influenced designers, engineers and business decision-makers. The company also emphasised that “the customer data and insight, in which Oxford Brookes were so instrumental in delivering has proved immensely useful too, especially in political conversations throughout the world” [5.2].

The MINI E UK project proved to be a strong basis for development of the BMW “ i” brand. The early project findings informed development of the 2011 BMW Active E, an electric derivative of the BMW 1 Series Coupe used to validate future powertrain developments, in preparation for the 2013 BMW i3, the first purpose-built EV from the BMW Group [5.2]. The i3 EV production began in September 2013 and it has been a highly successful model with more than 200,000 units sold worldwide by October 2020 [5.3] (sales value ~GBP6billion). It is now in its third evolution, with a larger battery pack and two performance versions.

The BMW Group has fully committed itself to electrification since the inaugural i3. By the end of 2019 BMW had sold over 500,000 electrified vehicles [5.4]. In September 2019, the MINI Electric made its public debut at the Frankfurt motor show and the first UK cars were delivered in March 2020. BMW Group said: “ MINI Electric is probably the best local success story, as what set out as a British applied research project many years ago has come full circle with the local production of the MINI Electric in the Oxford plant” [5.2]. The firm’s Oxford plant built more than 11,000 units by the end of July 2020 – more than 3,000 of which found homes on UK driveways, making Britain the EV’s second largest market [5.5]. The Managing Director of MINI’s Plant Oxford noted: “ Everyone at Plant Oxford is immensely proud that our hard work integrating MINI Electric into the production line is paying off, with the car proving so popular with customers in the UK and around the world. As the home of the brand, it gives us huge satisfaction to build the first fully-electric car in the MINI product line-up here in Oxford, for global export” [5.5]. By 2021, BMW Group will have five all-electric models, including MINI Electric and BMW i3, iX3, i4 and iNEXT. Additionally, they are committed to bring 25 electrified vehicles to the market by 2023 [5.2, 5.4].

Further influence on general acceptance of, and implementation strategies for, electric vehicles was enabled through collaboration with the UK Centre of Excellence for Low Carbon and Fuel Cell Technologies (CENEX). Together, OBU and CENEX combined information on driver adaptation, infrastructure requirements, cost barriers, EV charging behaviour and energy use, from all eight of the UK Ultra Low Carbon Vehicle (ULCV) trials to provide a national picture for the Technology Strategy Board (TSB) and Office for Low Emission Vehicles (OLEV) [5.6]. CENEX later reported: “ The programme outcomes identified infrastructure and cost barriers that influenced subsequent Government policy and actions such as further funding for EV deployments, learning activities, Plugged-in-Places funding to help urban regions with infrastructure installation … and undoubtedly influenced OEM EV developments and UK government policy” [5.7]. This is evidenced in the government’s continuing commitment to electrification through subsidies for EV purchase and home charging installation, zero road tax, provision of public charging infrastructure and unification of charge point access and payment for customers.

Impact on transport policy

Professor Hutchinson was an influential member of the Board of the Low Carbon Vehicle Partnership (LowCVP) 2014-16. This public-private partnership, part-funded by the Department for Transport (DfT), exists to accelerate a sustainable shift to lower carbon vehicles and fuels. SVEC’s whole life cycle research outputs, brought to the Board by Hutchinson, focused attention on energy and emissions of different vehicle types. The Managing Director of LowCVP stated: “…the work Oxford Brookes carried out, on the applications and on Life Cycle Analysis of the sector, represented a unique assessment of the broad full life GHG impact potential of the PLV (Powered Light Vehicle) relative to the existing body of work for conventional vehicles” [5.8]. SVEC’s research emphasized the need for small urban EVs and our life cycle assessment data and analysis were included in reports and supporting recommendations for adoption of future urban transport, such as ‘ Micro Vehicles - Opportunities for L-Category Vehicles in the UK’ (LowCVP, 2019) [5.9]. “The valuable work Oxford Brookes helped deliver within a unique collaboration of academic institutions in support of the LowCVP PLV initiative. The work LowCVP and the group have developed on PLV has been referenced within our subsequent activity on commercial vehicle applications, the ‘Future of Mobility’ consultations and within the overall Transport Decarbonisation plan due to be published by DfT (in Spring 2021). We fundamentally believe, based on the original work from our academic PLV interest group, that there is a huge opportunity for this vehicle category to contribute to both UK industrial strength and to the decarbonisation of UK transport in pursuit of our Net Zero targets”. [5.8, 5.10].

In summary, SVEC’s multi-disciplinary and cross-sector approach to analysing and addressing the technical and social elements around the transition to electric vehicles, has benefitted the automotive industry, consumers and transport policy-makers. It has played an important part in enabling the shift to the ‘new normal’ of electric vehicles, which has environmental benefits for us all. Further, our life cycle assessment model outputs are informing policy debate and strategic investment in UK battery manufacturing and recycling. Our work since 2011 has addressed the circular economy for electric vehicle traction batteries with a TSB pilot project, followed by a multi-partner EU Framework 7 project. We are now a partner in the Faraday Institution, EPSRC-funded, multi-partner GBP9,354,458 Reuse and Recycling of Lithium Ion Batteries (ReLIB) project (FIRG005, 2018-2021, Co-PI: Hutchinson).