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curiouscow393
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My friends and I were curious as to what the best angle was to blow on coffee to cool it down (actually only the coffee near the surface cools, so that's where we measured)
We did three trials each for 0°, 30°, 45°, 60°, 75°, and 90°.. all started around 88°C to 91°C measured every 30 seconds for 3 minutes while blowing on it with an electric pump (opening modified to simulate lips)
We got this result, graph of average degrees per second as a function of blowing angle
http://img11.imageshack.us/img11/9660/screenshot20111017at102.png
Uploaded with ImageShack.us
Aside from the air blowing away the vapor-saturated-air to keep evaporation going, we think we got this result because blowing down 60° caused an increase in surface area (by pushing down the water slightly on one side) and we think that the graph went down towards the end because surrounding pressure became greater than vapor pressure so evaporative cooling became less.
What do you guys think?
Btw, the red dot was the control, no blowing involved.
We did three trials each for 0°, 30°, 45°, 60°, 75°, and 90°.. all started around 88°C to 91°C measured every 30 seconds for 3 minutes while blowing on it with an electric pump (opening modified to simulate lips)
We got this result, graph of average degrees per second as a function of blowing angle
http://img11.imageshack.us/img11/9660/screenshot20111017at102.png
Uploaded with ImageShack.us
Aside from the air blowing away the vapor-saturated-air to keep evaporation going, we think we got this result because blowing down 60° caused an increase in surface area (by pushing down the water slightly on one side) and we think that the graph went down towards the end because surrounding pressure became greater than vapor pressure so evaporative cooling became less.
What do you guys think?
Btw, the red dot was the control, no blowing involved.
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