The following assumptions are the assumptions that were made on the model:
(i) the system operates under the steady state and isothermal condition; (ii) the fluid
velocity at all fluid-solid boundaries is equal to that of the solid boundary (no-slip
condition); (iii) isotropic and homogeneous medium fluid is assumed; and (iv) the cell
height on the bottom of the cell culture plate is negligible.
The SIMPLE (Semi-Implicit Method for Pressure Linked Equations) algorithm
was used to solve the Navier-Stokes equations iteratively. For accuracy’s sake, the
calculation in double precision was used. To prevent the oscillation of the solution, the
second-order upwind discretization scheme was selected. The under-relaxation factors
of the pressure, density, body forces, and momentum were set at 0.3, 1, 1, and 0.7,
respectively. The solution is iterated until the specified convergence criterion of 10−6 is
achieved.