The moment coefficient for incompressible flow, denoted as “cm,” is a dimensionless aerodynamic or hydrodynamic coefficient used to describe the pitching moment of an object, such as an airfoil or a hydrofoil, when it is subjected to fluid flow (e.g., air or water). The pitching moment refers to the tendency of the object to rotate or pitch about its center of gravity. The moment coefficient cm provides insight into how the object’s shape and orientation affect its stability and tendency to pitch or rotate when subjected to fluid flow. A positive cm indicates a nose-down pitching moment (the object wants to pitch down), while a negative cm indicates a nose-up pitching moment (the object wants to pitch up). Engineers and scientists use these coefficients to design and analyze the aerodynamic or hydrodynamic behavior of various objects, such as aircraft wings or hydrofoil blades, to ensure stability and control.Â
- Incompressible moment coefficient (cm,0)
- Freestream Mach number (M∞)
- Moment coefficient (cm)