Propeller-Nacelle Whirl Flutter

1962 ◽  
Vol 29 (3) ◽  
pp. 333-346 ◽  
Author(s):  
JOHN C. HOUBOLT ◽  
WILMER H. REED
Keyword(s):  
Whirl Flutter

Modeling Refinements in Simple Tiltrotor Whirl Flutter Analyses

2003 ◽  
Vol 48 (3) ◽  
pp. 186-198 ◽  
Author(s):  
Eric L. Hathaway ◽  
Farhan S. Gandhi
Keyword(s):  
Whirl Flutter

Whirl Flutter for Distributed Propulsion Systems on a Flexible Wing

2022 ◽  
Author(s):  
Nils Böhnisch ◽  
Carsten Braun ◽  
Stephan Koschel ◽  
Pier Marzocca
Keyword(s):  
Propulsion Systems ◽  
Flexible Wing ◽  
Distributed Propulsion ◽  
Whirl Flutter

On the Influence of Inflow Model Selection for Time-Domain Tiltrotor Aeroelastic Analysis

2021 ◽  
Author(s):  
Ethan Corle ◽  
Matthew Floros ◽  
Sven Schmitz
Keyword(s):  
Experimental Data ◽  
Particle Method ◽  
Comprehensive Analysis ◽  
Solution Stability ◽  
Step Size ◽  
Time Step ◽  
Time Step Size ◽  
Vortex Particle Method ◽  
Whirl Flutter ◽  
Vortex Particle

The methods of using the viscous vortex particle method, dynamic inflow, and uniform inflow to conduct whirl-flutter stability analysis are evaluated on a four-bladed, soft-inplane tiltrotor model using the Rotorcraft Comprehensive Analysis System. For the first time, coupled transient simulations between comprehensive analysis and a vortex particle method inflow model are used to predict whirl-flutter stability. Resolution studies are performed for both spatial and temporal resolution in the transient solution. Stability in transient analysis is noted to be influenced by both. As the particle resolution is refined, a reduction in simulation time-step size must also be performed. An azimuthal time step size of 0.3 deg is used to consider a range of particle resolutions to understand the influence on whirl-flutter stability predictions. Comparisons are made between uniform inflow, dynamic inflow, and the vortex particle method with respect to prediction capabilities when compared to wing beam-bending frequency and damping experimental data. Challenges in assessing the most accurate inflow model are noted due to uncertainty in experimental data; however, a consistent trend of increasing damping with additional levels of fidelity in the inflow model is observed. Excellent correlation is observed between the dynamic inflow predictions and the vortex particle method predictions in which the wing is not part of the inflow model, indicating that the dynamic inflow model is adequate for capturing damping due to the induced velocity on the rotor disk. Additional damping is noted in the full vortex particle method model, with the wing included, which is attributed to either an interactional aerodynamic effect between the rotor and the wing or a more accurate representation of the unsteady loading on the wing due to induced velocities.

Whirl Flutter Test of the Maryland Tiltrotor Rig: Overview

2022 ◽  
Author(s):  
Frederick Tsai ◽  
James R. Sutherland ◽  
Akinola Akinwale ◽  
Amy Morin ◽  
Seyhan Gul ◽  
...  
Keyword(s):  
Whirl Flutter

Nonlinear characterization of the piecewise structural effects on whirl flutter of a rotor-nacelle system

2022 ◽  
Author(s):  
Anthony G. Quintana ◽  
Brian E. Saunders ◽  
Rui Vasconcellos ◽  
Abdessatar Abdelkefi
Keyword(s):  
Structural Effects ◽  
Nonlinear Characterization ◽  
Whirl Flutter

Analysis of tiltrotor whirl flutter in time and frequency domain

2009 ◽  
Vol 23 (12) ◽  
pp. 3281-3291 ◽  
Author(s):  
Taeseong Kim ◽  
SangJoon Shin ◽  
Taehyoun Kim
Keyword(s):  
Frequency Domain ◽  
Whirl Flutter
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