Ignoring Radiation can cause Eggs to Boil...

I was at
COSMOS User Group meeting in Racine, WI. Knowing a good majority of them, I was
very happy to be surrounded by familiar faces. You know summer has kicked in;
when everyone keeps talking about latest grill on the market helping their culinary
skills to utopian levels. As everyone contributed their fascinating story, one
caught my attention the most.

An attendee claimed,
keeping a tray of eggs close to the grill caused the eggs to boil. Having
learnt from this experience, next time he kept beaten eggs; only to find a
crappy omelet in its place. The entire episode had his brain working in
overhaul. Humbled by the loss, he wanted to make sure he does not go hungry next
time. What he could not understand, how could the eggs get cooked if they were
not in direct contact with heat source?

The same
question can be asked a little differently. How can we feel heat from Sun, even
though we are not in direct contact? Radiation is the word we were looking for!
Radiation does not need a medium of transfer, it can happen in vacuum too. For
Radiation to occur, temperatures involved should be significant. Now, this is
obvious since both the Sun and grills operate at high temperatures.

COSMOS or
SolidWorks Simulation can be used to solve for radiative effect. How much an
object gets heated by radiation depends on how much is it exposed to heat
source. This is called as View Factor. View Factors are calculated using number
of rays traced from a surface. COSMOS uses an algorithm for Ray Tracing. This
technique models path taken by light when it hits an optical surface. There are
three possibilities to a light ray once it hits a surface (a) reflection (b)
refraction (c) absorption. This is the same technique that is used in designing
cameras and binoculars.

So next time
you are enjoying grilled food, make sure Radiation is not cooking you a meal!!!

Rajat Trehan

Product Manager - Design Validation

Computer Aided Technology Inc.