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Context and Methods for Improved Velomobiles

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This article discusses future transport emphasizing the aerodynamic cycles called velomobiles. Along with bicycles and ebikes, velomobiles are low energy transport which could displace cars as our commonly owned vehicles. Velomobiles are discussed in the light of emerging 3d printing, solar and structural battery technologies which could allow them and other cycles to be more useful and go further for less energy. Development and use of these technologies in velomobiles would benefit transport options and the technologies themselves, allowing beneficial and practical demonstrations in practical machines. Velomobiles using new technologies could be simpler and more relatable than cars and aeroplanes using the same technologies. The article aims to promote velomobiles and emerging solar, battery, and 3d printing technologies through their use in velomobiles. It highlights Australian researchers and manufacturers. Discussion includes the author's electric leaning trike which has timber panels replaceable by panels containing batteries or solar cells.
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Australasian Transport Research Forum 2019 Proceedings
30 September 2 October, Canberra, Australia
Publication website: http://www.atrf.info
1
Context and methods for improved
velomobiles
Stephen Nurse
10 Abbott Grove Clifton Hill Vic. 3068
Email for correspondence: cesnur@iimetro.com.au
Abstract
This article discusses future transport emphasizing the aerodynamic cycles called
velomobiles. Along with bicycles and ebikes, velomobiles are low energy transport
which could displace cars as our commonly owned vehicles. Velomobiles are
discussed in the light of emerging 3d printing, solar and structural battery technologies
which could allow them and other cycles to be more useful and go further for less
energy.
Development and use of these technologies in velomobiles would benefit transport
options and the technologies themselves, allowing beneficial and practical
demonstrations in practical machines. Velomobiles using new technologies could be
simpler and more relatable than cars and aeroplanes using the same technologies.
The article aims to promote velomobiles and emerging solar, battery, and 3d printing
technologies through their use in velomobiles. It highlights Australian researchers and
manufacturers. Discussion includes the author’s electric leaning trike which has timber
panels replaceable by panels containing batteries or solar cells.
1 Introduction
Creatures are not naturally wasteful, however with technological progress humans
have become wasteful. Waste accumulation harms environments and other
creatures, and our Earth is sickening from pollutants and carbon dioxide. We can
choose to alter our technological mastery and acknowledge some expedient
technologies are unacceptable, or to live in an uncomfortable dump.
Assuming we choose not to live in a dump, our future will involve reduced waste
including transport waste. This waste reduction will include low energy vehicles driven
by human power or renewably sourced electricity, not by fossil fuels. Our vehicles
should use the least amount of energy to do their job, and it can be seen in Figure 1
that electric cars use less energy than petrol cars and that bicycles use comparatively
little energy.
However bicycles may not be personally sustainable as owned vehicles, and improved
cycles such as electric bikes and load carrying, weather protecting velomobiles could
fill needs for lightweight, energy efficient, owned vehicles (Cosgrove 2012).
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Figure 1: Energy use in transport, adapted from Povkh and Ferreira (2018)
1.1 Personal and environmental sustainability
In cities we have transport choices, and to get from home to Richmond Station 5km
away, I can go by foot, bike, bus, train or car. Walking or running might take too long
or be exhausting. The bus is direct, but unfamiliar, and the train is indirect, involving
changing trains en route. By car, I can take luggage and passengers, but would have
to find a park when I get there. By bike I get exercise but can’t carry passengers or
much load but this would be my normal transport option.
Transport options change when going further and for the 120km to Anglesea, the
bicycle trip could be too long and tiring. Like the 5k walk or run, this trip might not be
personally sustainable and I would usually travel by car. On a 17,000km trip to Europe,
flying by aeroplane becomes the default option.
This describes my mobility, and my mobility combines with yours and the facilities we
use to become city-affecting transport systems. Resource consumption, greenhouse
gas emissions and use of space mean transport systems also affect the planet, and
can be environmentally sustainable to different degrees. Private ownership of vehicles
is part of sustainability and transport systems.
Owning a car means accommodating it at home, in transit and at destinations.
Businesses for car sharing and short-term use have proliferated recently, and their
familiarity and support is simplifying car-free living as shown in Figure 2. With sufficient
support, a bicycle or other human powered vehicle can become our only owned
vehicle, with electrically enhanced or other improved cycles making this more
personally sustainable (Apostolou 2018, Dijk 2013).
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Figure 2: Personally owned vehicles and sustainable transport (Author’s diagram)
1.2 Introducing velomobiles
Human powered vehicles include recumbent bicycles, recumbent tricycles and faired
recumbent tricycles or velomobiles as shown in Figure 3. Just as ebikes can have
better commuting range and hill climbing than bicycles, human powered vehicles can
have better stability, aerodynamics, load carrying and weather protection (Cox 2008,
Vittouris 2014).
Figure 3: Author’s recumbent bicycle, recumbent tricycle, velomobile (author, Smith 2014, McAdam 2018)
Frederick Van De Walle (2004) discusses the 365 Fiets competition where competitors
needed to carry luggage and average more than 35km/h in windy, rainy weather. Due
to difficult conditions and speed requirements, only recumbents qualified for the event,
and the winner was an Alleweder velomobile.
Van De Walle is enthusiastic about velomobiles, and so is Dillon Hiles (2014).
However Hiles is realistic about velomobile uptake in a time when electric bikes are
becoming more affordable. He states that like velomobiles, ebikes travel further for
less effort, but believes velomobiles will never become mainstream. This is because
of velomobiles’ extra weight, cost and size, and because unlike velomobiles, ebikes
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provide motive assistance on hills and during acceleration. He acknowledges that
velomobiles can have electric assistance too, and includes the solar electric Elf
velomobile in his list of iconic machines (Organictransit 2019).
Bicycles and velomobiles were included in a transport energy map (Figure 1) compiled
by Povkh and Ferreira. Within this map we should move towards sustainable
alternatives to preserve resources, prevent pollution, and ultimately have better lives.
Energy and pollution intensive aeroplanes and cars should become more
environmentally sustainable, and lower powered transport should become more used
by becoming more personally sustainable, useful, acceptable and affordable.
Regulatory assistance may be needed to drive change. For example Norway’s tax
incentives favouring sustainably fueled electric cars resulted in 58% of new vehicles
purchased in March 2019 being electric (Npr.org 2019). Norway have also mandated
that all flights within its borders be made by electric plane by 2040 (Bbc.com 2019)
which will drive clean emission technology development (Adam 2018, 1).
Having better electric and aerodynamic bikes is already achieving sustainable
transport: Melbourne cyclist Peter Wells reported changing from public transport to a
Valka Vista electric bike for his 17k commute, finding it reliable, useful and inexpensive
but heavy (Wells, 2019). Although my family still owns a car, it can sit unused for days
with most trips for visiting family, shopping and study done on aerodynamic cycles I
have designed and built, including a trike with a 250W pedelec electric motor. This
trike is used for a 20k round trip to nightschool and has proved reliable and easy to
own and use. Being very accustomed to pedaling my trikes, I use the motor mainly
for hills or starting at traffic lights (Nurse 2019).
Figure 4: Valka Vista e-bike with lights but no inbuilt luggage storage, Author’s aerodynamic pedelec trike
with lights and 50 litre of storage behind seat (Wells 2019, author)
1.3 Velomobiles in context
Improved cycles should include not only electric bikes but also statically stable trikes
and weather protecting velomobiles to make cycling an always-acceptable short-
distance option for most people (Cox 2006, Richardson 2010). Velomobiles can
complement other cycle types to make a diverse low energy cycle fleet, and together,
low energy cycles could become our default owned form of transport.
A velomobile can combine features from an electric utility cycle and a record breaking
speedbike. The electric utility cycle has load capacity, is easy to mount and can
replace short car journeys. Compared to unassisted bicycles, they carry more further
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with less effort, and compared to cars use less road and parking space while providing
useful exercise.
The speedbike is altogether different, designed only for going fast. To do that,
aerodynamics and low frontal area are emphasized above all else including easy
vehicle access. Although impractical for everyday transport, their aerodynamics can
be applied to their velomobile-practical-cousins to achieve improved speeds
independent of motors.
Figure 5: Top: Electric utility cycle and speedbike, and bottom: Velomobiles (Velo-ads 2018, Russo 2019,
Hasebikes 2019, Velomobiel.nl 2019, A1AA1A 2017)
Velomobiles are most commonly based on recumbent tricycles with the rider close to
the ground, so can be both statically and dynamically stable. They cover and insulate
the rider, so can be used in a wide range of weather conditions (Ferrari 2013). “Auntie
Helen” is an English cyclist living in Germany who has a prosthetic arm and blogs
about Germany and velomobile culture. She commutes by velomobile in all weathers
including snow and rain, routinely covering between 300 and 1220 kilometres per
month in electric and non-electric velomobiles (Helen 2019).
Australian velomobile manufacturers include Trisled and Gtrikes who make
velomobiles for road use and for the schools sport of Pedal Prix endurance racing.
Pedal Prix velomobiles are different to roadgoing machines because they must
accommodate a team of riders of different sizes and heights, and because they must
have seatbelts, roll cages and other safety requirements.
Australian roadgoing velomobiles include Trisled’s Rotovelo. It was introduced in
2011, and has a thermoplastic rotomoulded shell which is more robust than most
thermoset-plastic velomobile shells. Costs start at $6500: an electric motor assisted
version is advertised for $9500 and a lighter carbon-fibre-shell version is $10900 (Ball
2012, Trisled 2019)
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In 2019, Gtrikes bought the rights to produce the Greenspeed-developed Glyde
velomobile. Gtrikes development team includes contract aircraft builder Brett Turner,
and they aim to produce the Glyde in shell-as-frame / monocoque form. Greenspeed’s
Glyde production included a steel frame (Turner, 2019, Velomobile facebook group
2019).
Some Australian race series are part of education and development of sustainable
transport. One focusing on secondary education and use of alternate energy sources
is the Energy Breakthrough series where schools incorporate electric motors into
pedal prix velomobiles. This is held annually in Maryborough, Victoria (Pedler 2018).
An event held every two years is the World Solar Challenge with the next edition
running between Darwin and Adelaide from October 13 2019. Universities from around
the world compete. Although the event does not include human energy as a power
source, it features practical solar vehicles and light aerodynamic solar-electric vehicles
with composite bodies. Developments first trialed in the World Solar Challenge include
axial flux electric motors used on Avanti e-bikes (World Solar Challenge 2019, Charles
Darwin University 2006).
1.4 Scope and technologies
Although many technologies can be applied to improved cycles and velomobiles, this
article concentrates on several encountered through my 3d printing and cycle design
practice, reading, and contact with research groups and manufacturers. The
technologies 3d printing, solar cells and structural battery cells seemed underexposed
in relation to velomobiles, and as a method of selection I have focused on local
manufacturing and research with potential velomobile applications.
Other technologies which could improve velomobiles include hydrogen fuel cells which
have been researched by the University of New South Wales and the German
Fraunhofer Institut (Aguey-Zinsou, 2015, Fraunhofer 2019), and series hybrid electric
drivetrains (Nurse 2018, Fuchs 2014). These technologies are out of scope. Fuel cells
are complete systems encompassing fuel, energy conversion and electric drive, and
could be used in conjunction with the 3d printing discussed here. Series hybrid electric
drives have all their energy output delivered through a motor but can take energy from
human power, batteries, solar panels and other sources. All the technologies
discussed in this paper could be apply to series hybrid velomobiles.
Velomobiles may be new to many readers, and I have already introduced them.
However further analyzing velomobile use, commuting distances, cycling and
velomobile uptake, benefits in Australian weather, off-vehicle solar charging, and how
velomobiles could relate to Australian greenhouse gas emission goals is out of scope.
Suggested reading on these topics is Helen 2019 (velomobiles in everyday use), Van
De Walle 2004 (velomobile overview) and Cosgrove 2012 (Australian velomobile
uptake and potential for greenhouse gas abatement).
1.5 Aims
The article aims to provide a thorough introduction to velomobiles and their
characteristics with an emphasis on their role as sustainable transport. It aims to
promote emerging solar, battery, and 3d printing customization technologies by
showing their use, potential, and contributions in sustainable velomobiles. It hopes to
promote interaction by highlighting Australian researchers and manufacturers.
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Discussion includes the author’s electric leaning trike which has swap-out panels
which could be repurposed as batteries or solar cells.
2 New velomobile technologies
Velomobiles must be light to be carried easily, accelerated or propelled up hills by the
power supplied by humans and small electric motors (Van de Walle 2004, 100).
According to Van de Walle they are the most efficient form of transport. Despite this,
they share requirements for light weight with passenger aircraft, the least efficient
vehicles. The driver for light weight in passenger aircraft is fuel use: each kg of weight
saved in an aircraft can save approximately 3.8 tonne of aviation fuel (Appendix 1).
Velomobile technology already overlaps aeroplane technology in that both use strong,
lightweight materials including carbon fibre, and rely on aerodynamics for
performance. The following sections deal with technology for improving velomobiles:
solar power, right sizing and simulation through 3d Cad and 3d printing, and
incorporating batteries into structural materials. 3d cad and printing can make
improvements independent of any electrical assistance, while solar and battery
technologies could improve electrical assistance.
2.1 Custom 3d printed velomobiles
It is hard to imagine road cycle racing without the aerodynamic clothing riders use.
This clothing gives cyclists speed advantages of 6 -10% compared to street attire by
being slick and tight which improves the pattern and minimizes the volume of air
disturbance. Cyclist posture also influences racers’ frontal area, with riders reducing
area and effort by bending low when travelling at high speed (Kyle 1986).
Velomobiles are cycles which minimize air disturbance patterns using a fixed low-
profile body position and aerodynamic covering. However minimizing the area of air
they disturb could use more attention. This is because velomobile shells are routinely
made in moulds determining shell size with only one or two shell sizes available.
Figure 6: Cyclist’s frontal area: Determined by posture and clothing of racing cyclist but fixed for
velomobile rider. (Granada 2018, Trisled 2019)
Consider a velomobile designed for a person up to 180cm (5’11”) high and weighing
100kg. The velomobile works well for a person of that size, with snug clearances
between rider and body shell ensuring the velomobile has minimum size and frontal
area, and design ensuring components are strong enough for combined vehicle and
rider weight. Now consider a 163cm (5’4”), 60kg person in the same machine, which
may be the smallest available from a manufacturer’s moulds. Because clearances and
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component strengths are greater than necessary, the rider carries unnecessary frontal
area and overweight components. Assuming the velomobile height and width can be
changed in proportion with rider height, the frontal area can be reduced to 82% of the
original resulting in 6% more speed on the flat at 20 kph (Figure 7, Appendix 2).
Reduced size and weight mean the velomobile shell would weigh less, and
components could be less strong and weigh less, enabling better hill climbing,
acceleration and making lifting it safer and easier.
Figure 7: a) 180cm rider in correctly sized velomobile shell. b) With 163cm rider in the same machine, the
shell is oversized and the rider carries extra weight and wind resistance. c) correctly sized shell for 163cm
rider. (Author’s sketches)
a) b) c)
This-right-sizing of velomobiles for occupants should be possible by 3d printing
components including the shell. 3d cad, adjustable mock-ups, virtual reality and
scanning technologies could be used to size, visualise, prototype, evaluate, design
and advertise these new machines. One off velomobile shells could be printed to suit
a rider and their need to carry luggage.
3d printers have proliferated in the last 10 years with growth rates of 30% per year
since 2010, and are used for production to the extent that “Additive Manufacturing”
has become a term describing their use (Bourell 2016). 3d Printers are robotic
construction machines which interpret computer files describing 3d shapes as print
head movements to deposit material. The accumulated path of deposited material
results in real-world objects independent of casting moulds or material removal. 3d
printing can be carried out using biological, metal, concrete, ceramic, plastic, and
reinforcing fibre materials (Wu 2016) on scales from nanometres (=<0.01mm) to house
size (=>5m).
As well as a range of materials, 3d printing works with a range of coordinate systems.
My home 3d printer uses a 3 degree of freedom XYZ coordinate system. Another home
printer, the Anycubic Kossel uses the Delta system of 3 vertical, parallel, linear rails to
produce a 3 degree of freedom print head motion. More expensive printers such as
those from Australian Spee3d and Arevo use industrial robots to provide motion.
These robots can have more than 3 degrees of freedom, allowing material deposition
from variable angles, not just to particular points.
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Figure 8: Sub $400 3d printers, my Cetus 3d, and delta style Anycubic Kossel (author, Gearbest 2019)
3d printing technologies are scaleable, with human sized / cycle sized objects now
being printed using Delta technology. Tractus 3d vertical printers make life size
mannequins, and their largest model prints up to 2.1m high, just less than the lengths
(2.4m, 2.84m) of the Rotovelo and Quest velomobiles (Hiles, 2014, Tractus 2019).
Compared to traditional manufacturing methods, printing a velomobile could have
customization advantages, not only minimising frontal area and weight but also
providing luggage space, positioning mirrors and providing for use by other family
members.
Figure 9: Large scale printers: Australian Spee3d metal printer, Tractus3d delta printer (author, Tractus
2019)
Far from being a future manufacturing method for cycles, US company Arevo is
currently making 3d printed cycles which are vastly different from 3d printed bicycles
produced in 2011(Daily Mail 2011, Frptitan 2018). Arevo see their cycles as relatable
human-scale items that can be readily assessed in their own right. This relatability
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might not be present if the company were making (say) a car chassis. As well as
making frames for electric bikes for Oechsler, they have speculated on human
powered vehicle designs including load carrying bikes and a faired, tandem
recumbent. Without needing moulds, Arevo claim product development times of 18
days, down from 18 months for composite products requiring moulds. Arevo have
made Aerospace parts up to 2.5m x 1.5m (Daily Mail 2011, Frptitan 2018,
Compositesworld 2018).
Figure 10: 3d printed bicycles in 2011 and 2018. (Daily Mail 2011, Frptitan 2018)
Being able to 3d print custom-sized velomobiles is one thing, but being able to size
and market them is another. However existing technologies for capturing and
visualising riders on bikes could be used. Wearnotch sensors are worn on the body to
capture and display movement on smartphones and record movement as computer
files. This technology could be used in conjunction with an adjustable recumbent
exercise bike to capture motion, then calculate internal sizes for a velomobile.
Figure 11: Monash University adjustable speedbike simulator, application and use of of Wearnotch sensors
(Monash Human Power 2019, Wearnotch 2019).
An extension of Wearnotch technology would be to use its data to create virtual reality
environments including a proposed velomobile shell. Further inputs could include
pedal resistance to simulate riding and racing. These simulations could gamify and
show the speed potential of custom velomobiles. “Marky D” is a Sydney velomobile
user, and makes first person view videos from his Australian Rotovelo velomobile, the
sort of vision achievable in this proposed velomobile virtual reality. Due to the
aerodynamics of his machine, Marky will typically pass many, many cyclists in his
videos (geek.com 2016, Marky D 2019, Wearnotch 2019).
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Figure 12: Virtual reality in cycling, rider point of view from Marky D’s velomobile, velomobile racing
(geek.com 2016, Marky D 2019)
Measuring riders for correct velomobile size and strength, velomobile manufacture
using 3d printing, and virtual reality velomobile simulation could form a tool set or
ecosystem to encourage velomobile use. Ecosystems involving scanning, 3d printing
and mobility already exist, and examples include 3dprintedorthotics.com.au (2019)
who scan feet to produce printed shoe inserts helping customers walk and run, and
hexr.com (2019) who 3d print custom bicycle helmets after scanning the customer’s
head.
Figure 13: Ecosystems involving body scans and mobility: 3dprintedorthotics.com.au orthotics and
Hexr.com helmets (3dprintedorthotics.com.au 2019, Hexr.com 2019)
2.2 Solar
Solar power is a widely used renewable energy source. Solar energy is generated by
rooftop photovoltaic cells for off-grid and grid power generation, and stand-alone
photovoltaics for large-scale grid generation. Unlike base-load energy technologies
such as coal and gas fired power stations, solar power is intermittent, site dependant,
and changes on daily and yearly cycles. To provide constant electrical power,
photovoltaics must be connected to a battery or other energy storage (Kabir 2018).
Despite this intermittency, solar power is being used in more direct methods for
transport than simply supplying a grid which then charges electric vehicles. These
include static photovoltaics powering bike-share rechargers and on-cycle
photovoltaics (Gowrisankaran 2016). Static solar is out of scope for this paper, and
this section discusses direct on-cycle photovoltaics.
As mentioned, solar power is intermittent, and cycle motion makes on-cycle solar
panels even more intermittent than static panels (Apostolou 2018,10). However solar
power has been used in a range of vehicles including e-bikes, boats and planes, and
now velomobiles. Photovoltaics integrated into vehicles can be described as Product
Integrated Photovoltaics and a Dutch survey has concluded solar assisted electric
bicycles are effective transport (Apostolou 2018).
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When mounted above a velomobile, photovoltaics can form a canopy and protect
riders from sun, dust and cold. Configurations providing mainly sun protection can be
set up as a flat panel roof which minimizes extra wind resistance. This is favoured in
some solar bike races (Suntrip 2018).
However perhaps the factor most in favour of solar velomobiles and e-bikes could be
that modest amounts of electrical energy can power them (Rose 2012). An example
is an e-bike sold by Leaos with side-mounted solar panels transforming direct and
indirect sunlight into electrical power. The bike is carbon fibre and Leaos claim it can
recharge itself from sunlight only for daily rides of 15km (Leaos 2019). This recharging
comes from approximately 17dm2 of side-mounted panels. As a comparison, my e-
trike includes a 14.4 dm2 boot lid / top panel and 47.2 dm2 side panels. This area is
available for solar panelling and indicates my e-trike could be a good candidate for
including photovoltaics (Appendix 3, Figures 4 and 14).
Figure 14: Leaos Solar electric bike and solar charging system, author’s trike with side panel removed and
removable boot lid. (Leaos 2019, author)
Trailers fitted with solar panels can carry loads while powering the electric / human
powered vehicles they follow. Jürgen Burkholz designed a solar caravan for his trike
for the 25,000 km “Suntrip” solar bike race and went on to incorporate panels into a
load carrying trailer. Rob K’s electric trike with solar trailer features on the Azub
website and uses a 25% efficiency yachting solar panel (Burkholz 2019, Azub 2019).
There seem to be no commercial solar bike trailers although DIY builds have been
documented (travelbikesandstuff 2012). Commercial solar velomobiles include the Elf,
Evovelo and the Pedilio (Organictransit 2019, Evovelo 2019, Pedilio 2019).
Figure 15: Solar velomobile, Pedilio solar electric quad bike (Pvvelo 2019, Pedilio 2019).
Solar film technology from CSIRO promises to make solar energy provision lightweight
and able to be installed on a variety of surfaces. They have developed 19% efficient
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solar cells which could be applied to velomobiles to boost electric drives (CSIRO,
2018, Zuo 2018).
2.3 Battery technology
Velomobiles are generally heavier than bicycles because they include aerodynamic
fairings and an extra wheel. With batteries, motors and controllers, electric velomobiles
are heavier still. Velomobile weight reduction will improve performance, and weight
has been cited as a reason why e-bikes are more common than velomobiles (Hiles
2014). For a cue as to how electric assist velomobiles can be made lighter, aeroplane
technology can be observed. Just as carbon fibre was used in bicycles after being
manufactured for aircraft, (Roberts 2007) structural battery technologies proposed for
aeroplanes will benefit e-bikes and velomobiles.
Aerospace use and optimization of strong, lightweight carbon fibre material is now
standard, however new technologies promise to make aircraft lighter and more
efficient. Specific applications are to give unmanned aircraft greater range, and to
enable production of larger electric passenger aircraft. Research is now at aimed at
commercializing multiple simultaneous uses of carbon fibre material, or multifunction
composites. As well as providing structural strength these composites can be self-
healing, variable in surface roughness, thermally conductive, electrically conductive,
sensing, vibration damping or used for electrical energy storage (Jay 2015). Whatever
the new materials’ advantages, their after-original-design-life uses and recycling
should be established. Without this, the new materials could be solving one waste
problem only to create more (McDonough and Braungart 2010).
This section concentrates on electrical energy storage. Adam, Liao, Petersen et al
(2018) list five multifunction composite energy storage technologies and document
their advantages for use in electric aircraft. They see flight range extensions of up to
66% being possible through multifunction composites. Legault (2019) uses the term
“composite structural supercapacitors” to describe multifunction composite batteries
and considers that although their first application will be in military drones or
unmanned aerial vehicles they could one day power cars or trains.
If multifunction composites were used in electric assisted cycles or velomobiles, some
of the battery weight could be subsumed in the frame or shell weight. As well, cycles
or velomobiles could make good early, simple, visible, relatable, useful applications
for multifunction composites.
The first lightweight supercapacitor batteries may be available as panels, suitable for
installation into frameworks such as that on the author’s trike (Figures 4, 14) This type
of battery panel was researched by Volvo in 2010 (Asp 2015). Later developments will
increase complexity but improve strength and allow incorporation into monocoque
frames.
Swinburne university has a composite battery research department, with a paper by
Chan (2018) reviewing progress in the field. This paper discusses the strength and
storage capacity of novel materials, however Shirshova (2014) discusses working
prototypes of structural composite batteries. It seems actual use of structural
composite batteries is still years away.
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3 Discussion
All new cycles have relied on individuals and researchers including counter-cultural
advocates, early manufacturers, champions and demonstrators of new technologies’
effectiveness (Cox 2015, Richardson 2010).
After demonstrations of effectiveness, commercialization and widespread adoption of
technology can follow. However while I have ridden recumbent cycles on the road for
more than twenty years, I cannot see any increased uptake in recumbents or
velomobiles. Despite this, e-bikes and freight bikes have seen beneficial growth, at
least partly because mass-manufacture has brought prices down and because they
are effective (Wells 2019, Cox 2015).
Further work to promote velomobiles could include development of printable designs
for velomobile shells, development of generic designs for velomobile solar / battery
panel integration, and cost and technical analysis of technological combinations in
velomobiles. These combinations should include technologies outside the scope of
this report including fuel cell and series hybrid drivetrains.
However for more widespread adoption of recumbents and velomobiles of all sorts,
my advice is for openness in design and research, and the application of new
technologies in relatively simple human powered vehicles. Peter Cox (2015) cites the
low barriers to making, fixing and adapting cargo bikes as reasons for their continuous
use in Europe throughout the 1970’s. The barriers for adaption of new technologies
that will assist velomobiles should be kept low as well, with the use of technologies by
students or anyone who could become advocates as important as any other aspect of
research.
4 Conclusions
New technologies including 3d printing, virtual reality, structural batteries and flexible
solar cells could add significantly to the speed, usefulness and adoption of cycles
including velomobiles. Increased velomobile uptake would be a significant move
toward more sustainable transport.
Simultaneously cycles and velomobiles could showcase these new technologies in
applications which are simpler and more relatable than their use in cars or aerospace.
The highlighted technologies should be developed individually or in parallel to enhance
low energy transport. This development should not be limited to formal research in
universities: it is our role as researchers to encourage the wider use and seeding
demonstration of technologies we work on.
Acknowledgements
Thanks to Doctor Tim Corbett and my wife Christine for reading and commenting on
an early version of this paper.
Appendix 1: Fuels savings from lightweighting aircraft:
From Huang (2016): Each 100 kg reduction in the weight of an aircraft is estimated
to save 13.4-20.0TJ of fuel over the course of a 30 year life of an airplane This
translates to each kg saving an average of 167,000 Mj. Aviation fuel energy content is
approximately 43.5 MJ/kg (hypertextbook.com 2015). So approx. 3840kg of fuel are
saved per kg of aircraft weight reduction.
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Appendix 2: Speed increase with reduced cycle front area:
On flat ground and ignoring rolling resistance, the equation governing speed of a cycle
is Pr × (n/100) = Vr × (0,5 × rho × Cd × A × (Vr + Vw)2) , refer Van De Walle 2004
where Pr = power delivered to overcome wind resistance (at pedals) (W), n = power
transfer efficiency (%), Vr = vehicle speed (m/s), rho = air density (kg/m3), Cd = drag
coefficient, A = frontal area (m2) and Vw = wind speed against riding direction (m/s)
Assuming zero wind speed, and using a constant K to represent constants and
changed units, this can be reduced to:
K/A = (Vr)3, and for Vr = 20 kmh and A = 1 unit, K = 8000, then for 0.82A,
8000 / 0.82 = (Vr1)3, and Vr1 = 21.3 km/h
An online calculator (Gribble 2019) confirmed this, under otherwise
unchanged conditions a frontal area reduction from 1 to 0.82m2 showed a cycle
speed increase from 20 to 21.2km/h
Appendix 3: Area estimates for panels
As shown below, my 2d cad tracing of the Leaos Solar panels uses the wheel size to
obtain scale & indicates there are (2 x 8.7dm2 or) 17.4 dm2 of side-facing panels on
the e-bike. Cad data from author’s bike shows 14.4 dm2 top panel and (2 x 23.6dm2
or) 47.2 dm2 side panels totalling 61.6 dm2.
ATRF 2019 Proceedings
16
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