A method for computing the kernel of the downwash integral equation for arbitrary complex frequenciesFor the design of active controls to stabilize flight vehicles, which requires the use of unsteady aerodynamics that are valid for arbitrary complex frequencies, algorithms are derived for evaluating the nonelementary part of the kernel of the integral equation that relates unsteady pressure to downwash. This part of the kernel is separated into an infinite limit integral that is evaluated using Bessel and Struve functions and into a finite limit integral that is expanded in series and integrated termwise in closed form. The developed series expansions gave reliable answers for all complex reduced frequencies and executed faster than exponential approximations for many pressure stations.
Document ID
19840048967
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Desmarais, R. N. (NASA Langley Research Center Loads and Aeroelasticity Div., Hampton, VA, United States)
Rowe, W. S. (Boeing Commercial Airplane Co. Renton, WA, United States)