I wonder if in the formulation of the excersie 4 the maxmial outlet velocity in x direction is at the old outlet for the extendet pipe?
thank you for your patience. No here we are interested in the maximal velocity in x direction at the new outlet position. For comparibilty reasons (comparing 2 simulations with each other) it would be good to choose the same position. But here we are just interested you did the exercise correctly.