Many actions involve the use of diesel construction machines that release SO2 to the air. An action will release three sources of SO2 to the atmosphere. Assuming OD mixing, and given: • Modeling domain area A = 100 m by 100 m
• Height above ground where inversion (which traps pollution below it) begins at H = 414 m
• SO2 emission rates from the three sources E: = 100 g/s, Ez = 50 g/s, E3 = 15.6 g/s at volumetric flow rates Q. = 100 m/s, Q2 = 100 m/s, Q3 = 100 m/s
• Horizontal wind speed profile entering the CV is V = 0.45 20.20 with z in m and V in m/s
• Loss by chemical reaction is 1" order with k = 6.39 X 1051/s
• Loss by deposition is 1st order with a rate = Avec where the deposition velocity Va = 0.01 m/s and A is the domain surface area
• SO, concentration entering in on wind aka "upwind" concentration = C. = 10 ug/m
• SO2 concentration in CV immediately before action begins = Co = 10 ug/m
a. Draw and label a picture describing the problem.
b. Determine the flowrate of air leaving the airshed.
c. Determine the steady concentration of So, leaving the domain as a result of the action.
d. Assuming that all of the action's emission sources turn on at the same time, calculate the concentration of So, leaving the domain as a function of time, from the moment they are "turned on" (time zero) until steady state is reached. Create a graph showing the change.
e. Determine the time to reach within 1% of steady state and compare the time to your calculations and graph (from partc).
f. Explain why this problem would be OD and unsteady.