BIOE 498 Parameter Design Assignment
Questions and Answers
18 Sept 2008 - mjh

Assignment is (now) due Tueday 30 Sept.
- due date to be revisted Tuesday 23 Sept, for cause

O2 consumption = CO2 production
(quantum efficiency = 1)
- this ignores oxygen debt, etc. But it is close enough
  for this assignment

Assume total/instant mixing. There are plenty of fans stirring the air.
- this is *not* a gas diffusion assignment

In-flow rate is a constant (to be determined by the Assignment).
- there are no sensors for feedback
- it is too risky to vary the flow rate 

- - -

Discussion
23 Sept 2008 - mjh

Assignment is now due Thursday 2 Oct
- it took me 2 hours to do half of it
- at 5:1 multiplier (because I already "know" the answer)...

My solution so far uses an Excel spreadsheet
with about 32,000 cells
- 36 * 900
- but only a dozen or so equations!
- fill-down and fill-across don't add complexity

The trickiest part was dealing with the O2 consumption
- so many "steps" in time
- annoying to deal with as one equation
  If(0<t<6:30) then x else if (6:30<t<7) then y else...

  I set aside one column per time period
start
stop
liter/m
liter/min at 30 ft
times 4 people

  I end up with a *huge* but sparse array,
  and can sum across to get O2(t).

If this were done in Matlab or Python, it would be easy.

My dt was 5 minutes
- I should reevaluate for 1 minute increments, 
  to be sure that nothing is being missed

I did not "integrate" anything.
- I did derive the differential equation describing the system,
  but then I replaced that by a partial difference equation
  rather than solve the differential equation for the step-wise
  input.

My flow rate estimate is (greater than) 150 liters/minute