1. The problem statement, all variables and given/known data Write a vector field equation which describes fluid flowing around a pipe of radius r whose axis is a circle of radius R in the (x,y)-plane. 2. Relevant equations x2+y2=r2 Equation of a torus? 3. The attempt at a solution What I've gathered from the question: the pipe is in the shape of a torus of radius r and the circle of radius R runs through the center of the inside of the pipe. I know that two things describe this flow: 1. The magnitude of the flow decreases the farther away from the axis line on the inside of the torus that the point (x,y,z) is. 2. The flow goes either clockwise or counterclockwise around the origin in the (x,y)-plane. So the vector field equation for that piece is F(x,y)=<y,x> or F(x,y)=<y,-x> Otherwise, I have no idea where to start.