Which of the following is an assumption of Darcy's Law?

• A. Turbulent Flow
• B. Laminar Flow
• C. Compressible Flow
• D. Heterogeneous Formation

Answer: (B)

Darcy's Law is built on flow that is smooth and viscous-dominated inside porous media, so the fluid moves in a laminar regime where inertial effects are negligible. In this regime, the flow rate responds linearly to the pressure gradient, which is the hallmark of Darcy’s relationship. If the flow were turbulent, inertial forces would cause fluctuations and a nonlinear relationship, breaking the simple proportionality that Darcy’s Law describes. While incompressible fluids are usually assumed in the basic form, and simple analyses often take a homogeneous medium, the essential assumption tied to the question is that the flow is laminar. Compressible flow or highly heterogeneous formations require additional considerations beyond the basic Darcy framework.