Recommendations

In response to the suggestions made by the previous team, we have successfully completed
the construction of a 2-D scaled model and conducted numerous tests on the 1-D scaled
oven. In spite of the substantial progress made, there are definitely areas for improvement
as well as new ideas that are worthy of future consideration as project goals. In addition,
our trip to Nicaragua over Spring Break proved to an invaluable opportunity for knowledge
transfer, as members of both sides exchanged ideas and talked about problems with the
oven that can be addressed by future project teams.

Improving the Reflector Prop Rods

While in Nicaragua, we discussed possible problems that the women might be having with
their ovens. They happened to mention a problem with a component of the oven that we
have worked very little with at Cornell, the reflector prop rods. The women mentioned that
they could not use their box cookers during higher levels of wind since the wind would
blow their reflectors shut, rendering the box cookers useless. Since we do most of our
testing in the lab, we do not usually need to even construct the reflector since the lighting
system is directly above the oven that is being tested. However, we feel that it is important
to tackle this problem as a future project. It will be very important not only to come up with
new designs for the prop rods, but also to devise a method for testing their ability to
support the reflector during increased wind levels.

Testing

More testing on the 1-D scaled oven should be run to determine the oven capacity. Number
of pots and mass of water in each pot could be varied for these tests. Similar tests should
be run to determine the oven capacity for the smaller oven and the 2-D scaled oven.
Wind speed tests should be performed on the large oven to better determine the effect of
wind speed, and wind speed with or without silicone caulking. A good number of tests
should be run without wind to get standard data. Then wind speed could be varied to low,
medium, and high, as indicated on our fan, before silicone caulking. Then with silicone
caulking, wind tests should be performed again on no wind, low wind, medium wind, and
high wind.

When not doing the oven capacity testing, water less than the standard 5 lb should be used
to reduce cooking time, and hence to speed up testing.

Thermocouples

New thermocouples should be purchased, as many of the current ones are malfunctioning.

Additional Glass Strain Testing

The problem with breaking glass persists even with the bigger grooves in the new design. A
possible future goal would be to get the strain gauges to adhere to the glass properly for
data collection. We have another adhesive we want to use to bond the gauges to the glass:
Omega® OB-200. This adhesive is designed to go through thermal changes, so we think
that it will last longer than the M-Bond 600. Next semester we plan to attach another strain
gauge pair to the thermally neutral material, inside glass and outside glass and collect
enough data to figure out what the strain of the glass is as a function of temperature.

Lighting System with Parallel Rays

As mentioned in the previous final report, a lighting system with parallel rays would be
desirable for testing the parabolic cookers. Adding lenses onto the halogen lamps seems to
be a reasonable option for now. It would be a potential project for the future teams to look
into adjusting the lighting system.

Parabolic Trough

There are countless areas of small-scale solar capture that could use a parabolic trough to
provide their input energy. In order to keep this project targeted on a few specific goals,
the following topics of future research are suggested:

• Further refine the water pasteurization system to a degree where its operation is
  straightforward and intuitive.
• Investigate the coupling of the water pasteurization system to a UV irradiating
  system that first passes the water and highly concentrated sunlight through a clear
  pipe that does not attenuate a significant amount of UV rays. The water and
  majority of the initial light then could continue to the pasteurization system noted
  above for an enhanced purifying effect.
• Research the solar to mechanical energy transfer device further to determine
  whether a feasible device could be constructed and whether its complexities are too
  burdensome for the Solar Oven Group.