Modeling Helicopter Blade Sailing: Dynamic Formulation in the Planar Case

As part of a research project aimed at simulating rotor dynamic response during shipboard rotor startup and shutdown operations, a dynamic model of the ship–helicopter–rotor system that is appropriate for use in predicting rotor elastic response was developed. This planar model consists of a series of rigid bodies connected by rotational stiffness and damping elements that allow motion in the flapwise direction. The rotors were partitioned into an arbitrary number of rigid beam segments having the inertial and geometrical properties of a typical rotor. Helicopter suspension flexibility and damping were also modeled, although the helicopter was otherwise considered as a rigid body. Lagrange’s equation was used to derive the governing dynamic equations for the helicopter–rotor model. The effect of ship motion on blade deflection was also considered. The ship motion supplied as input to the model included representative frigate flight deck motion in three dimensions corresponding to an actual sea spectrum, ship particulars and ship operating conditions. This paper is intended to detail the dynamic approach adopted for this blade sailing study, and its conceptual validation in the planar case. The methodologies that have been developed lend themselves to easy expansion into three dimensions, and into torsion and lead/lag modeling. The amount of blade motion induced by ship motion on nonrotating helicopter blades is included. Although aerodynamic loads are a major contributor to blade sailing, this paper focuses on the dynamics aspect of the problem, and thus does not include aerodynamic effects.

[1]  Hao,et al.  Modeling and Simulation of Rotor Engagement and Disengagement During Shipboard Operations , 2004 .

[2]  Jonathan Allen Keller,et al.  Analysis and Control of the Transient Aeroelastic Response of Rotors During Shipboard Engagement and Disengagement Operations , 2001 .

[3]  Edward C. Smith,et al.  Analysis And Control Of The Transient Shipboard Engagement Behavior Of Rotor Systems , 1999 .

[4]  Edward C. Smith,et al.  Validation and Application of a Transient Aeroelastic Analysis for Shipboard Engage/Disengage Operations. , 1996 .

[5]  Edward C. Smith,et al.  Active Control of Gimballed Rotors Using Swashplate Actuation During Shipboard Engagement Operations , 2003 .

[6]  Jerry H. Ginsberg,et al.  Advanced Engineering Dynamics , 1988 .

[7]  André Heck,et al.  Introduction to Maple , 1993 .

[8]  Ronald L. Huston,et al.  Computer methods in flexible multibody dynamics , 1991 .

[9]  S Newman,et al.  The phenomenon of helicopter rotor blade sailing , 1999 .

[10]  Edward C. Smith,et al.  Recent Development in the Analytical Investigation of Shipboard Rotorcraft Engage and Disengage Operations , 1999 .

[11]  Edward C. Smith,et al.  Aeroelastic Analysis of Transient Blade Dynamics During Shipboard Engage/Disengage Operations , 1998 .

[12]  Edward V. Lewis,et al.  Principles of naval architecture , 1988 .

[13]  W. Thomson.  Theory of vibration with applications , 1965 .

[14]  Edward C. Smith,et al.  Experimental and Theoretical Correlation of Helicopter Rotor Blade-Droop Stop Impacts , 1999 .

[15]  Kevin A. McTaggart.  SHIPMO7: An Updated Strip Theory Program for Predicting Ship Motions and Sea Loads in Waves. , 1997 .

[16]  R. G. Langlois,et al.  A TUTORIAL PRESENTATION OF ALTERNATIVE SOLUTIONS TO THE FLEXIBLE BEAM ON RIGID CART PROBLEM , 2005 .

[17]  Olivier A. Bauchau,et al.  Multibody Modeling of Engage and Disengage Operations of Helicopter Rotors , 2001 .

[18]  S. J. Newman,et al.  The verification of a theoretical helicopter rotor blade sailing method by means of windtunnel testing , 1995, The Aeronautical Journal (1968).

[19]  J. Val. Healey.  The prospects for simulating the helicopter/ship interface , 1987 .

[20]  A. Lloyd,et al.  Seakeeping: Ship Behaviour in Rough Weather , 1998 .