incorrect way to set values for off-design points in example "electric_propulsor.py"

[peterrohl]

Code snippet starting on line 159 showing the incorrect loop:

# Set initial guesses for balances
prob['design.balance.W'] = 200.

for i, pt in enumerate(mp_propulsor.od_pts):

    # initial guesses
    prob['off_design.fan.PR'] = 1.2
    prob['off_design.balance.W'] = 406.790
    prob['off_design.balance.Nmech'] = 1. # normalized value

The example runs only because there is only one off-design point, and it happens to be named "off_design"
It should be done this way (from multi_spool_turboshaft.py):

for i, pt in enumerate(mp_multispool.od_pts):

    # initial guesses
    prob[pt+'.balance.FAR'] = 0.02135
    prob[pt+'.balance.W'] = 10.775
    prob[pt+'.balance.HP_Nmech'] = 14800.000
    prob[pt+'.balance.IP_Nmech'] = 12000.000
    prob[pt+'.hpt.PR'] = 4.233
    prob[pt+'.lpt.PR'] = 1.979
    prob[pt+'.pt.PR'] = 4.919
    prob[pt+'.fc.balance.Pt'] = 5.666
    prob[pt+'.fc.balance.Tt'] = 440.0
    prob[pt+'.nozzle.PR'] = 1.1