Aerodynamic load estimation: Pressure distribution from virtual strain sensors for a pliant membrane wing

Abstract

The passively adaptive behavior of flexible wings has demonstrated improved performance to that of rigid wings in the presence of low Re flow, near stall angles and flow disturbances. Throughout the natural world proprioceptive sensing is utilized by natural fliers to control their wings during flight. Through proprioceptive sensing of aerodynamic loads, information can be derived that is useful for flight control. Driving at that goal, an approach has been developed to utilize the strain sensed in a membrane wing to estimate aerodynamic loads generated. Hydrostatic pressure tests and wind tunnel tests were conducted to evaluate the capability of the estimation routine. Digital image correlation measurements were take to generate virtual strain sensors on the surface of the membrane. Measurements from a pressure transducer, load cell and CFD simulations were used as a basis of comparison to the estimated loads. Results of the estimation routine were favorable. Estimated pressure distributions closely resembled the actual distributions. The potential for extending this work include, a higher degree of estimate accuracy, estimation of dynamic loads and real-time load estimation.