In flight mechanics, trim velocity refers to the airspeed at which an aircraft can maintain straight and level flight without any changes in altitude or attitude (pitch, roll, or yaw) when specific control inputs are set to neutral or trimmed positions. Essentially, it’s the speed at which the forces and moments on the aircraft are balanced in such a way that it remains in stable, level flight without any tendency to climb, descend, or deviate from its current flight path.
- v: This represents the trim velocity of the aircraft. Trim velocity is the airspeed at which the aircraft can maintain straight and level flight with a specific configuration and without any control inputs.
- st/s: This term represents the wing area ratio. “st” typically stands for the total wing area (including both wings if it’s a multi-wing aircraft), and “s” represents the reference wing area, usually the area of one wing.
- CLαt: This is the total lift curve slope, representing how the total lift coefficient changes concerning the angle of attack (α). It accounts for the entire aircraft’s lift generation characteristics.
- iB: This represents the geometric mean of the aspect ratio (b²/S), where “b” is the wingspan, and “S” is the reference wing area. It’s a measure of the wing’s aspect ratio.