Month: June 2008

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Heat & Biking: Forced Convection and Heat Transfer

In the morning when I bike to work, it’s normally in mid to upper 70’s.  That’s pretty decent cool weather.  However, when I return, it’s low 90’s to high 80’s even after 6 pm!  😮  But when I do bike home, it doesn’t feel as hot as you’d think!

What the hell is “forced convection”?!  😀  Convection is heat transfer from one medium to the other through the fluid that surrounds the medium.  Basically, you release heat from solids or liquids to surrounding environment.  So in the case of biker, your heat dissipates to the air that surrounds you.  There are two kinds of convections:  free and forced.  Free convection is where the fluid that surrounds the boy in question is not moving, like swimming pool.  Forced convection is where the fluid is now moving, like the river.  What’s this got to do with feeling cooler when biking?!

Well, body temperature is 98 F to begin with.  So when ambient temperature is already in high 80’s to 90’s, there’s going to be not much heat transfer from your body to the air.  Heat transfer is directly related to the difference in temperature after all.  Yet in sitting still, free convection doesn’t help in dissipating your body as it gets hotter.  But once you get moving, air starts to move around you and you now have forced convection.  Forced convection basically, in layman’s terms, strips the heat away from you and thus increases the heat transfer rate despite the low difference in temperature.

So until I get home and stop, my body thinks that it’s rather cool outside still!  Science and engineering can be so nice, huh?!  😀

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Adapting to Life: Incorporating Biking

As I attempt to increase the frequency of riding the bike to work this week, it has introduced a new problem: lunch. Or rather, lack of ability to carry lunch to work. 🙁

I believe that in life, one has to always try hard to adapt to the changes that surrounds the person. After all, nothing stays the same forever, and getting too attached to habits of life can only bring in complacency. Last week, I just bought lunches at work cafeteria. There are two problems with this.

  1. Food taste and selection is terrible! It just plainly sucks.
  2. It is too expensive! Trying to eat healthy, chicken salad cost me $7 last week! 😮

I usually pack turkey sandwiches but the plastic container it resides in is too big! That definitely did not fit in my medium sized messenger bag that I take with me to work. It already contains my change of clothes on top of other sundry things.

To really make this healthy, green, and cost-saving habit to take full life, I had to make this lunch happen! Then this morning, it occurred to me. I could just pack individual sandwiches in its own smaller containers! It’s thinner (half the thickness) and would allow to be compact! Engineering at its finest! 😀 So I don’t have to spend too much money to buy lunch at work now! Yeah!

Even in engineering, you have to constantly adapt to different challenges, as new problems always ensue. Here’s to successful biking to work three times this week! Depending on how well this week goes, I may just bike to work all 5 days next week! Here’s to your health.

And for the last part, I wanted to thank all those that cared about my health and thus kept pestering me over and over and over… and over! 😛 That means thanks goes to Soojin, my dearest wife, my mom, and my mother-in-law!! Ha ha ha… Thanks everyone.