Sudden Expansion in Laminar Pipe Flow

Problem Statement

Consider a fluid flow through a sudden expansion in an axisymmetric pipe. The flow is laminar and axisymmetric. Due to symmetry, the computational domain covers only half of the pipe. BD is the axis of symmetry.  The radius R1 = 1m and R2/R1 = 2.

L1/R1 = 20 and L2/R2 = 50. The inlet velocity at AB is uniform, U1 = 10.277 m/s . The fluid exhausts into the ambient atmosphere which is at a pressure of 1 atm at CD. The density ρ = 1kg/m3 , and the dynamic viscosity is:

µ = 3.61x 10-2kg0.01 kg/(ms).

The Reynolds number Re at AB = (2 R1 ρ U1) /µ = 55.4.

...