Abstract:
The need to develop alternative energy sources for road transport has been growing
daily due to depleting fossil fuels as well as the need to control toxic vehicular emissions.
One of the most viable solutions developed in response to these concerns has
been the electric car. The current electric cars however suffer from reduced range
(in comparison to an Internal Combustion Engine (ICE) vehicle of the same price).
Therefore there is need to research on additional green energy sources to supplement
the energy stored in the batteries of electric cars.
This research sought to develop an additional energy source for electric cars by exploiting
the fact that any vibrations and strains like the ones experienced in a car’s tire can
be converted into electrical energy using pre-stressed piezoelectric elements.This was
done by first simulating the vehicle tire behavior using Simscape software to model
the kind of forces that would be expected at the contact patch of the tire when in use.
This information was then used with COMSOL multiphysics software to establish the
most suitable piezoelectric element size (in terms of thickness) to use with such tires.
Equipped with this data, a trial tire with embedded piezoelectric elements was developed
and tested in the lab before fixing it on a Nissan Wingroad DBA Y12 car for
the testing. The power output under all the above different road conditions was analyzed
in order to understand the specific behavior of pre-stressed piezoelectric tires in
automobiles
It was found out that each 25 mm diameter piezoelectric disc gives out a maximum of
0.5 mW of power.
Using the NissanWingroad as the experimentation car with the maximum 192 2:65=
508 piezoelectric elements per wheel, it is possible to generate 1.1 Watts from the four
tires at any given instance. The results from this research therefore can be used as a
guideline in designing of future piezoelectric tires.
