The Design In Life

Posted by Cate W. | Posted on November 6, 2011

There is no doubt that you will spend most of your undergraduate career studying lecture notes, reading book and textbooks, and doing problem sets.  As a college student, and in particular as an underclassman, you gain knowledge and techniques for solving problems on paper.  This year a club I have been involved with since the beginning of my freshmen year, ChemE Car, became a three-credit design course.  The previous two years, we spent a lot of time theorizing, and I’ll be honest and say that the group lacked organization and possessed some of the worst leadership I have ever witnessed.  This year our faculty mentor, Dr. Frechette, decided to make the club a course, and it has helped tremendously with the progress of creating this small, shoebox-sized car, which is both powered and stops solely by chemical reaction.

The class is split into three groups, one group designs a chassis and researches and tests on all things related to gears, motors, and general physical design of the car.  Another team designs a chemical stopping mechanism, which through controllable variables like concentration and knowledge of kinetics of the reaction ultimately stops the car.  Lastly is the third team, which researches propulsion mechanisms, which is the team I am on.  Within my team, we are split into two groups; one group is working on developing a battery, and my group is developing a propulsion mechanism that uses the thermoelectric effect.  There are three members in the group, myself, one of my very close friends, and a freshmen, who is learning the ropes.

A previous, more successful experiment.

Design classes are like no other.  Not only do you need to do the book work, where you research the theoretical concepts, but you also need to design experiments, build the apparatus, and be prepared to analyze your data and explain your results.  You also have to find a time where you are your partners can meet.  Sometimes your partners unexpectedly cancel on you, and you are left alone.

There have been constant ups-and-downs with our design.  Ultimately, in the end of the semester we need to produce a car that works.  That gives us less that a month to get it working.  Our module uses liquid nitrogen as a cold sink.  If you don’t know anything about liquid nitrogen, it gets cold, very cold.  In fact it gets to negative 176 Celsius.  It sounds perfect in theory for our purposes.  However due to the extremity of the liquid, we have run into many problems.  Last week we did our first experiment, which was an utter failure.  We poured the liquid nitrogen into an aluminum flask, but you couldn’t cap the flask because the flask would explode as pressure builds when the gas boils at room temperature.  Thus cold nitrogen gas was forced to flow over our whole apparatus, which depends on there being a temperature difference to operate.  The plastic box broke due to cold.  Ultimately we got a third of the voltage that we measured during previous experiments.

These are thermoelectric generators, which use a temperature gradient to produce an induced emf.

I think liquid nitrogen is a lot like the obstacles we face in life.  It has its extremes, and this very unique property of causing way more problems that should be expected.  On paper you have it all worked out, all the equations, the calculations, the references, just like in life.  But when you go to practice what you have learned, the experiment doesn’t always go as planned.  Sometimes life just utterly explodes and falls apart.  Sometimes stress feels like a heavy freezing gas that slows you down.  Sometimes in the end you succeeded a lot less than you had to be expected.  Life is like a engineering design problem, but you can learn something from each failure.  In the end you can clean up the lab, turn off the lights, and walk out, only to be prepared to come back tomorrow and try the experiment again.

1 Comment

  1. JHU Peter says:

    Design projects are hard, but rewarding in the end. I’m sure you’ll figure it all out!

    p.s. you forgot to mention the blowtorch!

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