What factors cause an increase in friction loss?

An increase in friction loss in fluid flow typically results from factors such as velocity, viscosity, and roughness.

Velocity directly impacts friction loss because as fluid flows faster, it encounters greater resistance from the surface it moves against, leading to increased energy loss due to friction. This is often characterized by the turbulence of the flow; higher velocities tend to cause turbulent flow, which has more friction losses compared to laminar flow at lower velocities.

Viscosity also plays a significant role in friction loss. It is a measure of a fluid's resistance to flow, and higher viscosity fluids experience greater friction losses, as they cannot easily move past each other or the surfaces they are in contact with.

Roughness refers to the texture of the surface through which the fluid is flowing. A rough surface increases the friction between the fluid and the surface, leading to an increase in friction loss. This aspect is crucial in engineering applications where materials and surface finishes can greatly affect flow efficiency.

These three factors—velocity, viscosity, and roughness—are fundamental in calculating and predicting friction losses in pipelines and other flow conduits. The other options contain elements that do not directly correlate with friction loss, such as temperature and pressure, which primarily influence other fluid properties but are