Final answer:
In Darcy's Law, K represents hydraulic conductivity, which indicates how easily fluid flows through a material. It plays a critical role in calculating the flow velocity of a fluid in porous media, as per Poiseuille's law for laminar flow.
Step-by-step explanation:
In Darcy's Law for flow velocity, the equation V = (K/n) * (dh/l) is used to describe laminar flow through a tube, often referred to as Poiseuille's law. Here, K represents the hydraulic conductivity of the material, which encapsulates how easily fluid can flow through it. The hydraulic conductivity, K, depends on the properties of the fluid and the porous medium.
For instance, a larger K value suggests a material that allows fluid to pass through it more readily, such as gravel or sand when compared to clay. This concept is crucial in fields like hydrogeology, civil engineering, and soil physics, where managing and understanding fluid movement through porous substances is essential.
The hydraulic conductivity, along with the fluid's viscosity (n), the hydraulic gradient (dh), and the length of the flow path (l), determines the velocity (V) of laminar flow according to Darcy's Law.