3.   Laminar and turbulent case.

Laminar case :

    This part aims to familiarise us with the PROSTAR features that enable simple problems to be set up in a relatively short time. The computation was done with an inlet velocity of 0.02 m/s.

    The velocity profile is what was expected. Indeed the fluid passes through the labyrinth with quite no perturbations. There are "dead zones" where the fluid does not move.
    The pressure profile shows a pressure gradient with a higher pressure at the inlet, which is also whats was expected.

Turbulent case :

    For the turbulent case, the inlet velocity was 2 m/s. The turbulence model was the k-eps model.

    This initialisation was done with the assumption of 10% of turbulent intensity.

            k is the turbulent kinetic energy
                            I is the turbulent intensity and I = 10 %
          eps is the turbulent dissipation and l the turbulent mixing length.

        Then we get:                        k = 0.06
                                                        eps = 0.483

    The velocity profile shows us recirculations of the fluid. The outlet velocity is about 4 m/s. In the laminar case, the outlet velocity is 0.04 m/s. This speed up of the fluid is due to the decreasing size of the path.

    As it was for the laminar case, we can notify a higher pressure at the inlet than at the outlet. This gradient is low but high enough to entail the flow through the labyrinth.

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