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Novel Compound Rotary Engine Range Extender for Electric Vehicles

Periodic Reporting for period 1 - CREEV (Novel Compound Rotary Engine Range Extender for Electric Vehicles)

Reporting period: 2015-07-01 to 2015-12-31

Rotary engines were conceived in 1929 and compared to piston engines, they provide high power/weight ratios in a compact form factor with low levels of vibration. However, rotary engines are often associated with high rotor tip wear, noise, poor efficiency and higher emissions than piston engines. The CREEV project addresses the disadvantages associated with rotary engines, opening up new opportunities in markets currently dominated by piston engines.

CREEV exploits two innovations: The first of these improves combustion efficiency & reduces emissions. This provides higher power density, improves fuel consumption and reduces noise. The second innovation delivers effective engine cooling which reduces temperature gradients within the engine. This results in reduced rotor tip wear, improving reliability and efficiency. When fully commercialised, CREEV will deliver compact, lightweight and efficient/clean engine technology with no requirement for oil filters or a sump. This reduces weight further and simplifies maintenance. Much interest has been shown in the technology and testing has already demonstrated very promising improvements in power, efficiency and noise reduction.

There is significant potential for CREEV, not least in the automotive sector, which has been evolving rapidly in recent years, driven by interest in electric vehicles (EVs) with very low emissions. Road transport contributes about one-fifth of the EU's total CO2 emissions, so greater adoption of EVs is a key part in supporting CO2 emissions within this sector. However, range anxiety remains a key barrier to mass-uptake of such vehicles and it has been reported that although 44% of drivers consider emissions to be important when selecting a car, only 5% would actually buy an EV due to range concerns. Better methods for extending range between charging stations are therefore needed to allow the EV market to reach full potential. Range extenders have been developed to address these concerns, but these are based on piston engines. Ideally, an EV requires a small, quiet and high power/weight ratio range extender that occupies less space. CREEV addresses this market need.

The main project objective is therefore to successfully scale up CREEV and further optimise performance. In addition to identified potential in automotive markets, this technology also has exciting potential in applications associated with aeronautical and marine markets.
A feasibility study has been completed, based on the activities listed in the original Phase 1 project application. Specifically, these activities included 1. Risk assessment, 2. User engagement, 3. Engine testing, 4. Market studies, 5. IP management strategy and 6. Business plan refinement.

Effective risk management is crucial for project success and a comprehensive risk assessment was undertaken. The outputs from this work has already been used in planning further work and devising an effective work plan. The assessment exercise included technical, commercial, environmental and management risks. Higher risks have been identified and contingency plans developed.

User engagement activities have been undertaken with a number of potential end-users and stakeholders. This was achieved by discussion at industry events, shows and meetings with focussed end-user groups. Several automotive manufacturers have expressed high levels of interest in the technology in range extender solutions. This included support from a broad range of sectors including very small (quadricycle) manufacturers, cars, sports cars and Light Commercial Vehicle (LCV) sectors. The automotive market continues to be the primary application and main focus for exploitation of CREEV. It is also worth noting that user engagement identified that rotary engines offer distinct advantage in marine markets where there is a requirement for quiet and efficient power to operate vessels in port or shallow waters without having to use large, powerful marine diesel engines. In addition, there are increasing needs for autonomous maritime platforms to recharge batteries and operate flexibility. Similarly, there is also potential in Unmanned Aerial Vehicle (UAV) markets where high power/weight ratios are a primary selection criteria to enable better payload or range capability. Applications for UAVs include aerial surveillance, fire-fighting and first responder applications. It was also apparent that there is increasing demand for range-extended multi-rotor UAV platforms. With anticipated 400% increase in range and 20% reduction in emissions, CREEV is also expected to deliver environmental benefits and lower running costs.

Engine testing was carried out on the prototype CREEV unit using an engine water brake dynamometer test rig. The findings of the test were documented, with data being acquired on the engine dynamometer using a standard and modified engine to quantify performance benefits. Specific Fuel Consumption (SFC), power output (hp) and noise level (dB) data was gathered over a range of engine operating speeds between 4000 and 6000rpm. Test results showed that at 5,500rpm, SFC increased from 0.55lb/hp-hr to 0.69lb/hp-hr (25% improvement) and that power increased from 17.1hp to 20.1hp (17.5% improvement). A decrease in engine noise was also demonstrated, even at higher power levels and optimisation activities have been identified to improve engine performance further.

Market studies were undertaken which showed that as range extender technology improves, hybrid EVs are expected to be widely adopted in the market place. As countries seek to address future energy requirements in a rapidly growing and changing world, achieving sustainable transportation has emerged as a vital mission. EVs represent one of the most promising pathways to increased energy security and reduced emissions of greenhouse gases and other pollutants. By helping to diversify the fuel mix, EVs reduce dependence on petroleum and tap into a source of electricity that is often domestic and relatively inexpensive. The last three years have seen a remarkable surge in demand for electric vehicles. It is reassuring to note that the market is moving in a direction that will create increasing demand for range extenders and ‘range anxiety’ was confirmed as a key barrier to wider vehicle adoption. LCV operators are also under increasing pressure to minimise emissions and the ability to drive into a large
This project significantly advances state of the art for rotary engines. It seeks to successfully demonstrate and scale up for market readiness, a completely novel, high efficiency, low emission, compact rotary engine range extender for electric vehicles. Despite the increasing popularity of environmentally friendly electric vehicles, greenhouse gas emissions continue to rise in the sector. This is because of range anxiety, the single greatest obstacle to the widespread adoption of EVs and the environmental benefits they offer. As a result, while 44% of drivers consider emissions & environmental friendliness as important factors when buying a car, only 5% would consider buying an electric car due to range concerns.

Whilst automotive manufacturers have sought to address the issue of range anxiety through the installation of range extenders, existing extenders are limited in performance and do not fully meet market needs. The clear business opportunity is to provide tier 1 automotive powertrain providers and OEMs with breakthrough innovation in EV range extender technology that meets all of their needs. These include; high efficiency, low fuel consumption, low emissions, low noise, compact size, light weight and low vibration. The rotary engine lends itself extremely well to this application, but has a number of inherent limitations. This project addresses those limitations whilst building upon the inherent strengths of the rotary engine. Releasing the full potential of this technology is expected to lead to wider adoption of EVs, providing societal and environmental benefits. CREEV is novel, patent protected and lab tested/demonstrated at prototype stage.
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