UWE Bristol Engineering showcase 2015

Timothy Stone
Mechanical Engineering (Meng)
Project Supervisor
Richard Stamp
Project summary
Speed Bump Design for Energy Collection
Concept Prototyping
Upon setting up the system it quickly became
apparent that generating energy was not possible.
When applying any load whilst keeping the plastic
tubing level, water came out and span the wheel,
however, when connecting the dynamo, the wheel
was unable to overcome the frictional forces as
Figure 35 demonstrates. Even when using a garden
hose at mains pressure, the velocity of the water
was still inadequate and unable to move the wheel
when the dynamo was attached. Although this test
could be seen to have failed, the wheel was able
to move very quickly when the dynamo was not
attached, which proves the force was able to
convert into rotational velocity, if the wheel could
overcome the friction then this experiment would
have generated results. To confirm the friction
could not overcome different shaft diameters,
fluid storage and tubing were all tested without
providing results.
Material Selection
A static simulation was complete with permanent
fixings, to stop movement or rotation. The speed
bump was also secured to stop movement in the
normal direction; so it would act as if on a road of
no compressibility. The pressure was assumed to
act either across the surface area of the car tyre or
evenly distributed across each side, dependent on
how the force acts, or the size of the vehicle being
tested. This was to give the maximum stress
possible throughout simulations.
Project Conclusion
The prototype tested (hydraulic) was not successful,
regardless of the fluid velocity created as adequate
water pressure could be generated to overcome the
friction of the dynamo. It did allow a redesign to be
conceived which allowed modifications of the
prototype which would hopefully minimise this
issues. The testing did indicate however that in
practise the system may not be feasible due to size,
number of components and exposure of certain
components to the environment. A prototype should
be developed with minimal moving parts to reduce
issues of friction forces and accommodation space.
The power output calculations for the potential
generation of electrical energy together with the data
collected for the vehicle populous indicates that the
amount of energy could be obtained through speed
bump design. Although energy generation may result
in a lower
Power output then targeted proximity sensors could
be used to reduce the energy consumption at times.
The study for the potential energy generation of
speed bumps was initiated with research and data
collection; this was to establish the possible energy
generation by finding average vehicle populous,
average vehicle weight and the required power
output to illuminate a 50 watt street lamp. Other
measures were investigated for feasibility, including
regulations, safety and costing, which established
dimensions, placement and technology, so testing
could take place. It was decided that speed bumps
would be designed for 20 mph zones, which would
reduce initial costing, enabling speed bumps to be
surfaced fixed to the road, therefore omitting
expensive excavation.
Using suitable technologies, concepts were designed
and compared against each other, and the hydraulic
prototype was selected for testing. Although testing
was unsuccessful, construction issues previously
encountered were improved by modifications to the
design. The testing lead to the conclusion that the
concept selected may not be suitable, therefore
alternative prototypes were developed for further
study.
From observing the four different simulations, the
highest stress level was selected, so the material
would have to withstand a yield stress of 8.5MPa.
If a factor of safety of three is to be used, the
actual value for yield stress required is 25.5MPa.
From the initial research and data collected it would
appear that energy generation from speed bumps is
feasible and there are several possible options
available for further development whilst following
the design specification.
Project Objectives
Initial Research, research of similar products, study
literature and designs ideas.
A potential solution to solving this issue is to
reduce the friction by either creating a gearing
relationship between the dynamo and the wheel
or by designing a solid shaft which holds the
water wheel and the rotational shaft of the
dynamo.
To find the most suitable material, a program
known as Cambridge Engineering Selector was
used. By setting the minimum properties as
discussed and setting each material.
Fibreboard is suitable, as it can be easily made
weatherproof and the majority are produced from
sustainably grown timber, which is abundant in the
United Kingdom, and are also produced from parts
of a tree which have no other use
Vehicle Research, including populous, weight
distribution and energy loss.
Energy Generation, find required power outputs,
consider environmental impacts.
Initial, product and material testing
Product design, development of concept ideas
through sketches and selecting a suitable design.