Table 1. Boundary Conditions and Solver Settings.

set condition	definition of boundary condition/initial condition
inlet	pressure inlet (p = 3.0 MPa)
outlet	pressure outlet (p = 4.0 MPa)
coupled (wall)	outer surface of channel
flux algorithm	second order upwind
solution strategy	SIMPLE
turbulence model	realizable K-ε
turbulence intensity	0.01
turbulent viscosity ratio	10
initial velocity scale of turbulence	1 m/s