Airflow from rotor rotation that is modified by induced flow is called which of the following?

• A. Resultant Relative Wind
• B. Relative Wind
• C. Induced Wind
• D. Turbulent Wind

Answer: (A)

In rotor aerodynamics, the blade doesn't see just the forward wind or just the downwash from the rotor; it sees their combination. The rotor lifts air and creates an induced flow downward through the rotor disk. This downward flow modifies the airspeed and direction over the blade, so the actual wind acting on the blade is the vector sum of the freestream relative wind (the wind from forward flight) and the induced downward flow. That combined wind is called the resultant relative wind, and it is what sets the blade’s angle of attack and the lift it can produce. The other terms don’t capture this combined inflow: relative wind would ignore the rotor-induced downwash, induced wind would emphasize only the downward component, and turbulent wind is not the standard term used here.