The Effects of Reynolds Number on Rotor Stall

The effects of Reynolds numbers have been associated with the scaling of model data to full scale data. However, today's fixed and rotary wing aircraft experience large changes in Reynolds number due to variations in speed and altitude which could effect the performance of both unless they are anticipated. The importance of Reynolds number in considering flow similarity has been established in fixed wing aerodynamics. Its effect on rotary wing aerodynamics is not as well understood. Model rotor data is available to today rotorcraft aerodynamicist, but comparative full scale data is lacking. In this situation, we are forced to turn to mathematical models of the rotor to explore the influences of Reynolds number. The theoretical foundations of rotary wing mathematical models lie in fixed wing aerodynamics. Thus, our basic hypotheses about the effects of Reynolds number have been drawn from this discipline. The study outlined below utilizes an existing mathematical model to relate our fixed wing knowledge of Reynolds number effects to the rotary wing and gain an understanding of the effects of Reynolds number on rotor stalls