# FLUIDS: Potential Flow Question - HELP NEEDED

1. May 1, 2013

### EngrDelaCruz

FLUIDS: Potential Flow Question -- URGENT HELP NEEDED

I need to submit this soon and I am way behind in this topic. I would appreciate it a lot if you can help me out figure the answer.

1. The problem statement, all variables and given/known data
In a uniform onset flow of 7 m/s parallel with the x axis, a source of strength 19 m2/s per metre is located at the origin (x=0, y=0) and a sink of equal strength is located at (x=2, y=0). Locate the x axis position of the most upstream stagnation point.

Diagram:

2. Relevant equations
I think it will be these:

3. The attempt at a solution
Figuring out the stream function:
Psi = (lambda / 2pi)(theta_1 - theta_2)
....
v=7m/s

...

Ugh.. please just help me out on this. It's 5% of the unit. Thanks

2. May 1, 2013

### Staff: Mentor

The velocity of the flow from the 19 m2/s source is $\frac{19}{2π\sqrt{x^2+y^2}}$ and is directed radially outward.

The velocity of the flow from the 19 m2/s sink is $-\frac{19}{2π\sqrt{(x-2)^2+y^2}}$, and is directed radially outward.

According to the problem statement, the stagnation point is along the x axis (y = 0).

The combined overall velocity along the x axis is U + ?? + ??. What are the ??'s?