Hi

In Ergun equation, you have two parts, (part1)*U + (part2)*U^2 where:

Part 1 = (150*mu/Dp^2) * ((1-eps)^2/eps^3)

Part 2 = (1.75*rho/Dp) * (1-eps/eps^3)

It depends on which model you are going to use in OpenFOAM,

with Darcy-Forchhiemer model, apply D = part 1 and F = part 2

with fixedCoeff model, apply alpha = part 1 & beta = part 2

Dear mahdi,

I have already resolved the problem, i had issues in understanding the drag model implementation within OpenFoam.

Although i have correctly validated pressure drop from ergun's equation.

I am still thankful for your response.