modeling consists of solving the equations of motion
within the pore space, subject to boundary conditions
imposed by the (typically) complex pore structure. It is
the most rigorous and detailed approach to modeling
fluid flow, but also the most computationally demanding.
A number of numerical techniques are available, and the
best choice depends on factors ranging from the Reynolds
number to the fluid rheology to the pore structure.
Because of the computational
demands (and corresponding limitations on domain size),
streamline-scale modeling is rarely used directly for
engineering problems. However, it is essential for
studying fundamental transport processes. The
information gained is then incorporated into network
models, continuum models, or upscaled by some other