Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 38
Book Description
Conical Euler Simulation and Active Suppression of Delta Wing Rocking Motion
Author: Conical Euler Simulation and Active Suppression of Delta Wing Rocking Motion
Author: National Aeronautics and Space Administration (NASA)Publisher: Createspace Independent Publishing Platform
ISBN: 9781722126056
Category :
Languages : en
Pages : 36
Book Description
A conical Euler code was developed to study unsteady vortex-dominated flows about rolling highly-swept delta wings, undergoing either forced or free-to-roll motions including active roll suppression. The flow solver of the code involves a multistage Runge-Kutta time-stepping scheme which uses a finite volume spatial discretization of the Euler equations on an unstructured grid of triangles. The code allows for the additional analysis of the free-to-roll case, by including the rigid-body equation of motion for its simultaneous time integration with the governing flow equations. Results are presented for a 75 deg swept sharp leading edge delta wing at a freestream Mach number of 1.2 and at alpha equal to 10 and 30 deg angle of attack. A forced harmonic analysis indicates that the rolling moment coefficient provides: (1) a positive damping at the lower angle of attack equal to 10 deg, which is verified in a free-to-roll calculation; (2) a negative damping at the higher angle of attack equal to 30 deg at the small roll amplitudes. A free-to-roll calculation for the latter case produces an initially divergent response, but as the amplitude of motion grows with time, the response transitions to a wing-rock type of limit cycle oscillation. The wing rocking motion may be actively suppressed, however, through the use of a rate-feedback control law and antisymmetrically deflected leading edge flaps. The descriptions of the conical Euler flow solver and the free-to-roll analysis are presented. Results are also presented which give insight into the flow physics associated with unsteady vortical flows about forced and free-to-roll delta wings, including the active roll suppression of this wing-rock phenomenon. Lee, Elizabeth M. and Batina, John T. Langley Research Center RTOP 505-63-21-01...
Conical Euler Analysis and Active Roll Suppression for Unsteady Vortical Flows about Rolling Delta Wings
Author: Elizabeth M. Lee-RauschPublisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 36
Book Description
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