Solar Radiation: How Engineers Can Stay Cool on the Beach (Maybe)
Fanny Griesmer August 29, 2012
The end of August marks the end of summer here in New England. Already nostalgic and unwilling to let the season go, I decided to look into some “beach physics”. In May we released a new solar radiation feature in our Heat Transfer Module that will be helpful in many solar applications — including how to avoid overheating on the beach, apparently. Here’s how engineers can stay cool on the beach.
Some of you may have been stuck at work all summer, but if you’ve had the time to go to the beach you’ll have experienced the unforgiving strength of the sun’s rays and what it does to your body (dehydration, sunburn, etc.) — not to mention how it warms the contents of your cooler. Warm drinks aren’t very refreshing in the summer heat. Now, let’s bring your cool logic from your workstation and apply it to a sunny beach scenario. If you bring a beach umbrella and a cooler to the beach, how hot will each of these items get? In our Heat Transfer webinar earlier this month, John Dunec said: “This [beach scenario] is a fun problem, but the same question goes for the solar industry; how do you do that?” There must be a way to model your way out of this solar conundrum.
There is a way to model this in COMSOL Multiphysics. That’s one thing I learned from that Heat Transfer webinar. Thanks to the new solar radiation feature in the Heat Transfer Module, you can figure out the answer to this problem pretty easily. First you define the external radiation source; next you set the latitude and longitude of your location, along with the date, time of day, and time zone. This provides you with a 1D plot of how the beach umbrella and cooler heat over time for a given solar irradiance:
If you then plot this in 3D you’ll get the shading throughout the day:
Enticed by the prospect of bringing physics to the beach? Also read Valerio’s blog post on “Singing Sand Leads to Many Questions”.