Due to Team Momentus's desire not to release information about
new design developments prior to the World Championships in March
the following page relates to the car used at the UK National Finals
in 2007.
Research
The first step in designing Team Momentus's car was to research
into existing car designs and the general physical principles
that affect their performance. This included research into basic
aerodynamic principles.
To create an object, around which air can flow smoothly,
the profile of the object in all three dimensions has to be
carefully considered. A fast moving object must be designed
in order that it causes the minimum disturbance and movement
in any fluids through which it is travelling. To achieve this
the object must be designed to incorporate curves that can
guide fluids from front to rear in a smooth manner.
This will minimise the disturbance caused in the fluid.
The aim is that the airflow will follow the objects surface;
if it does not then flow separation occurs and a void or
low pressure spot will form behind the object resulting
in eddies. If an object causes disturbance in a fluid through
which it is passing then the object is transferring energy to
that fluid. This ultimately means that the object’s own kinetic
energy and thus velocity are being reduced. It is therefore
desirable that an object causes as little disturbance in a
fluid as possible.
Design
Following the production of rough hand sketches several designs were produced
using ProDesktop, in order that they could be tested to determine which
design features gave the best performance.
Testing
Computational fluid dynamics modelling combined with the use of a physics engine
that Team Momentus derived and programmed were used to test the relative performance
of different designs.
Manufacture
The cars were manufactured using CAD/CAM technology to cut the desired shape from
a block of balsa wood. A small amount of hand finishing was then required before
painting and fitting of the wheels.
