The NACA airfoil series
The early NACA airfoil series, the 4-digit, 5-digit, and modified 4-/5-digit, were generated using
analytical equations that describe the camber (curvature) of the mean-line (geometric centerline) of
the airfoil section as well as the section's thickness distribution along the length of the airfoil. Later
families, including the 6-Series, are more complicated shapes derived using theoretical rather than
geometrical methods. Before the National Advisory Committee for Aeronautics (NACA) developed
these series, airfoil design was rather arbitrary with nothing to guide the designer except past
experience with known shapes and experimentation with modifications to those shapes.
A centrifugal pump converts input power to kinetic energy by accelerating liquid in a revolving device - an impeller.
The most common is the volute pump - where fluid enters the pump through the eye of the impeller which rotates at high speed. The fluid accelerates radially outward from the pump chasing and a vacuum is created at the impellers eye that continuously draws more fluid into the pump.
A centrifugal pump converts input power to kinetic energy by accelerating liquid in a revolving device - an impeller.
The most common is the volute pump - where fluid enters the pump through the eye of the impeller which rotates at high speed. The fluid accelerates radially outward from the pump chasing and a vacuum is created at the impellers eye that continuously draws more fluid into the pump.