Ok, let's find the complex potential just to get you going
If , we have
, so q is a model flow.
Now to find the complex potential , we find its real part as the function to satisfy . The first equation gives , and substituting into the second one we get or , so and .
Now we find the streamline function as the imaginary part of . Since and are conjugate harmonic, we get that .
The first one gives or , and by substituting this into the second one , from which and finally .
We obtain the complex potential as .
Now set constant for the equation of streamlines, etc.