Problem 4-2. Pressure-Driven Flow Through a Slightly Deformed Tube. Consider flow through a straight tube that is due to a constant-pressure gradient, p/z=G. The cross section of the tube is rS=R(1+sin) where (r,,z) represent a circular cylindrical coordinate system. Assume that 1, and use the method of domain perturbations to determine the steady-state velocity field in the tube to O(2). Is the volumetric flow rate per unit cross-sectional area larger or smaller than the flow through a circular tube? Discuss the answer to this question from the point of view of a macroscopic force balance