Estimation of parameters involved in high angle-of-attack aerodynamic theory using spin flight test dataThe difficulty in applying parameter estimation techniques to spinning airplanes is due in part to the unwieldy number of possible combinations of terms in the equations of motion, when the model structure is unknown. The combination of high angle of attack and high rotation rate results in aerodynamic functions which are quite complex. For wing dominated configurations it is advantageous to use aerodynamic theory to generate the model structure. In this way, the number of unknown parameters is reduced and the model accuracy may be increased. Under conditions for which the theory is inadequate, however, model accuracy may be reduced. Strip theory, for example, is incapable of predicting autorotative rolling moments indicated by wind tunnel tests at angles of attack exceeding 40 degrees. An improved aerodynamic theory would be necessary to successfully apply the technique advanced for such regions.
Document ID
19830062591
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Taylor, L. W., Jr. (NASA Langley Research Center Hampton, VA, United States)
Pamadi, B. N. (NASA Langley Research Center Hampton, VA, United States)