Viscosity is the property of a fluid that describes its resistance to flow. It is a measure of the internal friction between fluid particles.

Hydrostatic pressure is the pressure exerted by a fluid at a given point due to the weight of the fluid above that point.

The principle of conservation of mass states that mass can neither be created nor destroyed, only transferred from one place to another.

The Bernoulli equation is a fundamental equation in fluid mechanics that describes the conservation of energy in a fluid flow.

The lift force generated by an airfoil is primarily due to the pressure difference between the upper and lower surfaces of the airfoil.

The Reynolds number is a dimensionless quantity used to characterize the fluid flow regime and determine whether the flow is laminar or turbulent.

The Navier-Stokes equations are a system of partial differential equations that govern the motion of viscous fluids.

The Darcy-Weisbach equation is used to calculate the pressure drop in a pipe due to friction.

The Moody diagram is a graphical representation of the friction factor for pipe flow as a function of the Reynolds number and relative roughness.

Cavitation occurs when the pressure in a fluid drops below its vapor pressure, causing the liquid to vaporize and form bubbles.

The principle of buoyancy states that an object immersed in a fluid experiences an upward force equal to the weight of the fluid displaced by the object.

The Froude number is a dimensionless quantity used to characterize the fluid flow regime and determine whether the flow is subcritical or supercritical.

The Mach number is a dimensionless quantity used to characterize the fluid flow regime and determine whether the flow is subsonic, transonic, supersonic, or hypersonic.

The Prandtl number is a dimensionless quantity used to characterize the fluid viscosity and thermal conductivity.

The Nusselt number is a dimensionless quantity used to characterize the heat transfer between a fluid and a solid surface.