Shocks are not accounted for

[runphilrun]

The script does not account for normal shocks that may form in the diverging portion of the nozzle
http://seitzman.gatech.edu/classes/ae3450/normalshocksCDnozzles.pdf

[runphilrun]

TDU now checks to see if shocks exist in the nozzle. soon will be able to locate shocks