[rbwally]

Dear you,

Now I am doing a steady state simulation in Fluent with pressure based solver.

Boundary condition:

Velocity inlet (Velocity 10 m/s, Reynolds number 4000), pressure outlet, and other sides are periodic and symmerty.

Mesh quality:

Minimum orthogonoal 0.2.

Turbulence model:

RNG ke with enhanced wall treatment.

Pressure drop is defined as:

Static pressure of (the inlet - outlet).



My question is:

Why the pressure drop fluctates in a sinoidal pattern with in a range of 2 Pa, even the residuals of continuity and so on below 1e-5?



BEST REGARDS

[Indra]

Originally Posted by rbwally

Dear you,

Now I am doing a steady state simulation in Fluent with pressure based solver.

Boundary condition:

Velocity inlet (Velocity 10 m/s, Reynolds number 4000), pressure outlet, and other sides are periodic and symmerty.

Mesh quality:

Minimum orthogonoal 0.2.

Turbulence model:

RNG ke with enhanced wall treatment.

Pressure drop is defined as:

Static pressure of (the inlet - outlet).



My question is:

Why the pressure drop fluctates in a sinoidal pattern with in a range of 2 Pa, even the residuals of continuity and so on below 1e-5?



BEST REGARDS

Fluctuation in sinosoidal pattern is completely fine as long as the flux are conserved and the fluctuation is very small im comparison to the actuall pressure values.
The fluctuation occur because of small numerical errors(residuals) or maybe the problem itself is not inherently steady in nature.