Menteşe Moment

Menteşe is defined as the hinge moment caused by aerodynamic forces acting around the hinge axis of a surface (winglet, elevator, rudder like). This concept is critical in the design of control surfaces for aircraft such as airplane and helicopters. The hinge moment determines the force the pilot must apply to move the control surfaces and directly influences flight characteristics.

The hinge moment is associated with $(M_h)$

\( M_h = \frac{1}{2} \rho V^2 S c C_h \)

• \( \rho \): Air density (kg/m³),
• \( V \): Velocity (m/s),
• \( S \): Area of the control surface (m²),
• \( c \): Characteristic length of the control surface (typically the chord length),
• \( C_h \): Hinge moment coefficient (a dimensionless coefficient).

The hinge moment coefficient depends on the angular position (\( \alpha \)) and the deflection angle of the control surface (\( \delta \)).

$C_h=C_{h_0}+C_{h_{\alpha }}\alpha +C_{h_{\delta }}\delta$

Computational Fluid Dynamics (CFD): The pressure distribution and forces are simulated to calculate the C_h coefficients.

Theoretical Models: Solutions are generated using thin airfoil theory or panel methods analytic.

• Fixed-wing Aircraft: Elevator, aileron and rudder design,
• Helicopters: Pitch control of rotor blades,
• Rockets and Unmanned Aerial Vehicles (UAVs): Sensitivity of autopilot systems.

The concept of hinge moment gained importance in the early 20th century as aircraft design became more complex. Particularly during World War II, control difficulties encountered in high-speed aircraft accelerated the development of aerodynamic balancing techniques.