Consider ventilation of a well-mixed room as in Fig.

Chapter 7, Problem 27P

(choose chapter or problem)

Problem 27P

Consider ventilation of a well-mixed room as in Fig. P7-27. The differential equation for mass concentration in the room as a function of time is given in Prob. 7-27 and is repeated here for convenience,

There are three characteristic parameters in such a situation:L, a characteristic length scale of the room (assume L = V1/3);V̇, the volume flow rate of fresh air into the room, and climit the maximum mass concentration that is not harmful. (a) Using these three characteristic parameters, define dimensionless forms of all the variables in'the equation. (Hint: For,example, define c* = c/climit.) (b) Rewrite the equation in dimensionless form, and identify any established dimension: less groups that may appear.