This example is a two-dimensional study of a fluid flow within a channel with a backwards-facing step.
The flow pattern will again be calculated using the incompressible Navier-Stokes equations for a Reynolds number of Re = 250, which for this problem lies in the laminar range (the transitional range lies between 1200 < Re < 6600).
The geometry consists basically of a box, representing the channel, with a step on the channel bottom.
Backward-facing step Viscous, non-turbulent case Reynolds number of 250 |
The Reynolds number is defined here as: Re = 2νmax D r / 3m with the characteristic length of the problem, D being the height of the inlet channel.
The factor 2/3 derives from the assumption of a parabolic velocity profile in the inlet section with vmax being the maximum velocity value attained in this section.
The Reynolds number derives from the choice of the following parameters:
D = νmax = 0.5 m/s r= 1000 kg/m3 m= 2 kg/ms |
According to the previous equation we obtain
Re = 250 |
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