Jaguar Land Rover (JLR) is literally intent on harvesting energy saving solutions. “We are researching a range of new technologies to drive even more weight out of our vehicles, including how we could mix carbon fiber with flax,” reveals its R&D Director, Dr. Wolfgang Epple.
He says JLR is pursuing a bold electrification strategy and believes electric solutions are a must for premium carmakers to drive fleet average CO2 emissions below 100 g/km (U.S. 56 mpg). But creating vehicles which are more fuel-efficient and sustainable "cannot be achieved by the introduction of hybrid and battery powertrains alone," he asserted, while noting that JLR's ‘Evoque-e’ research project with 12 technology partners includes a new and unique design of high performance, modular electric motor generators.
A high CARBIO diet
The wider, complementary technologies are needed to achieve the holistic solutions required, Epple stressed, including parasitic losses in all areas: drag coefficient, friction, electrical, and heating, cooling and ventilation systems. And there is the need for more innovative approaches to weight reduction. That's where flax (a cultivated crop; textile fiber is obtained from its stem) and carbon fiber, enter the equation.
Simon Black, a JLR Senior Manager for Bodyshell and member of Epple’s team, explains: “The CARBIO project, in which we are a partner, combines layers of carbon fiber and flax with an environmental-friendly cashew nut oil resin. Flax was chosen for its inherent sound dampening properties. CARBIO combines the strength and lightweight benefit of carbon fiber with the sustainability and lower cost of flax. While the manufacturing cost of CARBIO is similar to that of traditional carbon fiber, the material cost of mixing carbon fiber and flax is one-third cheaper.”
Components made from CARBIO are 28% lighter than aluminum and 55% lighter than steel. Its NVH properties mean less use of sound-deadening material, Black noted.
But even the weight of the material that is required, could also be reduced via a research project calls LANDS (Lightweight and Sound) examining development of new NVH-abatement materials. One of these uses recycled plastic combined with filler sourced from the sugar refining process. A prototype wheel arch liner has been produced that is 9% lighter than a typical current type but provides similar noise reduction capability.
The CARBIO project has developed a carbon/flax hybrid automotive roof using Composites Evolution's Biotex Flax material. Together with vibration damping properties, flax fibers are renewable, lower in cost, and are CO2 neutral. Bio-epoxy resins based on cashew nut shell liquid (CNSL) can offer enhanced toughness, damping and sustainability over synthetic epoxies.
A 50/50 carbon/flax hybrid biocomposite, made from Biotex Flax supplied by Composites Evolution and prepregged by SHD Composite Materials, has contributed to achieving the objectives of the project. With equal bending stiffness to carbon fiber, the hybrid biocomposite is described as exhibiting 15% lower cost, 7% lower weight and 58% higher vibration damping.
The prototype roof was designed by Delta Motorsport and manufactured by KS Composites. The CARBIO project is part-funded by Innovate U.K. (the British Government’s innovation agency). Other partners include Cranfield University.
Another significant project involving JLR is Varcity, evaluating how the company could introduce carbon fiber materials into its existing mixed material strategy for body structures with enhanced NVH properties, compared to current carbon fiber applications. The target is to achieve a 20% weight saving against an aluminum BIW.
“Varcity’s starting point was the Jaguar C-X75 concept,” says Black. “The bodyshell used an out-of-autoclave molding technique compatible with higher volume manufacturing.” Varcity is continuing R&D work on processing and forming technologies that could meet cost and volume requirements.
Vehicle wiring loom and electrical components are also getting the weight-loss R&D treatment, with the possibility of replacing them with wafer-thin printed electronic circuits. Typically a current Range Rover carries some 6000 m (19,685 ft) of wiring weighing 94 kg (207 lb). Use of thermoplastics for lighter seat construction are showing promise and the project PLACES (Premium Lightweight Architecture for Carbon Efficient Seating) has demonstrated seat structure 30% lighter than an equivalent in steel with no sacrifice of comfort, stated Black.
A thermoplastic composite stamping process is used. The structural components work as part of the comfort system for consolidation of parts.
New e-motor architectures explored
JLR’s thermal management team is looking at the possibility of heating or cooling a cabin via what it terms an “air bubble” to maintain an equable temperature via several technologies including infra-red solar reflective glass, bespoke for specific temperature zones.
JLR also envisages infrared panels invisibly embedded parts of the cabin to warm occupants’ skin instead of maintaining the entire cabin at a specific temperature. Early tests show that it is possible to halve HVAC energy consumption from the current 8-12 kW.
All this is significant work, but it is powertrain that remains JLR's main single focus for energy saving. Mike Richardson, JLR’s Chief Technical Specialist, Low Carbon Vehicles, explains that the Evoque-e collaborative research project (12 partners and part-funded by Innovate U.K.) aims to look beyond 2020 to explore all aspects of advanced electrified powertrain technology. One of the key areas is to develop new, electric machine architectures.
“The radial flux machines that form the core technology for this are slim, light and extremely powerful,” states Richardson. “They produce up to twice the power and torque of current production technology. And they are scalable, capable of supporting any size of vehicle in our range and being modular, compatible with generic future components and systems.”
There is an added environmental plus for the new electric machines: “For applications where ultimate performance is not the priority, we are developing a version of the motor which trades iron-based ferrite magnets for typically used rare-earth neodymium, and copper windings instead of aluminum windings.” Savings are financial as well as environmental, he said: “An electric machine architecture this flexible will allow us to produce virtually any hybrid or battery electric vehicle configuration we choose.”
Evoque-e technology demonstrators embrace mild hybrid, plug-in hybrid, and battery-electric configurations. The mild HEV has a 66-kW (88.5-hp) 3-cylinder diesel research engine with a 15-kW (20-hp) radial flux electric machine integrated between the engine and a standard 9-speed auto transmission. This power unit is connected to a 48-V electrical system and 48-V lithium ion battery.
The plug-in has a prototype JLR Ingenium 2.0-L 4-cylinder engine and also has a radial flux electric machine (capable of up to 150 kW linked to a 320-V lithium ion battery) module between it and an 8-speed automatic.
The pure electric vehicle has a 70-kW lithium ion battery and electric machines front and rear powering electric drive axles. The front axle is integrated with a single speed transmission and 85-kW (114-hp) machine using a ferrite magnet and aluminum winding; the rear a smaller 145-kW (194-hp) machine. It uses traditional neodymium magnets and copper windings for added performance but driving through a 2-speed transmission.
There is more to come, and Dr. Epple reveals that JLR will double the size of its advanced research team to 500 within two years, focusing on long term multi-disciplinary challenges: “Electrification, smart and connected cars, and HMI (Human Machine Interface), all of which will help us deliver a low carbon future.”
And supported by "flaxable" solutions, of course.
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