| Luke H. Peristy |
Doctoral Candidate, Royal Military College of Canada, Department of Mechanical and Aerospace Engineering, Kingston, Ontario, Canada, K7K 7B4. | | Ruben E. Perez |
Associate Professor, Royal Military College of Canada, Department of Mechanical and Aerospace Engineering, Kingston, Ontario, Canada, K7K 7B4. |
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| Abstract:
This paper presents a multi-modal analysis framework which is used to examine the interactions between a C-130 tanker aircraft and F/A-18 refueller during AAR for the purposes of predicting handling qualities during the AAR task. This work is motivated by the need to rapidly clear tanker-refueller pairs for safe operation in the event of multilateral operation between groups with different refuelling platforms. The framework uses a vortex panel method with an actuator disk propulsion model to predict air velocities in the tanker wake. A vortex panel representation of the refueller is then combined with a closed-form aerodynamic model to find the trim points at various locations in the tanker's wake. The positional stability of the refueller is examined, finding areas of positional stability within the bounds of the tanker's wingspan. A simplified controller model is combined with 6-DOF, 9-state equations to predict the closed-loop natural modes at the trim points within the tanker wake. The closed-loop eigenvalues of the 9-state system are not predicted to change appreciably during refuelling compared to steady level flight. However, examination of the eigenvectors shows cross-coupling effects. Due to this cross-coupling, it is theorized that a purely eigenvalue based analysis will be insufficient to predict handling qualities during AAR. Therefore, it is suggested that frequency and bandwidth-based handling quality assessment criteria be examined.
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View PDF CEAS-GNC-2022-057