Vibration Reduction on Helicopter Rotors Using Open Loop Flow Control

2021 ◽  
Author(s):  
Ryan P. Patterson ◽  
Peretz P. Friedmann
Keyword(s):  
Flow Control ◽  
Vibration Reduction ◽  
Open Loop ◽  
Helicopter Rotors

Open-Loop FLow Control on a Torsionally Flexible NACA0018 Wing

2017 ◽  
Author(s):  
Keaton L. Turner ◽  
Casey P. Fagley ◽  
Jurgen Seidel ◽  
Thomas E. McLaughlin
Keyword(s):  
Flow Control ◽  
Open Loop ◽  
Torsionally Flexible

Piezoelectric Actuators Used for Helicopter Vibration Reduction

2013 ◽  
Vol 718-720 ◽  
pp. 1729-1733
Author(s):  
Zhu Zhang ◽  
Wei Dong Yang ◽  
Da Lin Yang
Keyword(s):  
Vibration Reduction ◽  
Piezoelectric Actuators ◽  
Scaled Model ◽  
Helicopter Rotors ◽  
Bench Tests ◽  
Advantages And Disadvantages ◽  
Model Helicopter ◽  
Trailing Edge Flap ◽  
Drive And Control ◽  
And Control

This paper covers the development of two piezoelectric actuators for trailing edge flap control on mach scaled model helicopter rotors. The design, analysis and bench tests of these two actuators are described. Under different voltages and frequencies, their drive performances are tested and compared. Results showed that these two actuators all can effectively drive and control the flaps with each advantages and disadvantages.

Investigation of POD Bases for Flow Control on Disk Wakes

2010 ◽  
Author(s):  
Zachary Berger ◽  
Rory Bigger ◽  
Makan Fardad ◽  
Hiroshi Higuchi ◽  
Mark N. Glauser ◽  
...  
Keyword(s):  
Velocity Field ◽  
Flow Control ◽  
Linear Time ◽  
Open Loop ◽  
Synthetic Jet ◽  
Time Dependent ◽  
Space Representation ◽  
Control Input ◽  
Time Resolved ◽  
Lti System

This work investigates the effects of flow control on the near wake region of a disk in a water flow, utilizing the POD reconstructed time dependent velocity fields. Velocity measurements were collected using time resolved particle image velocimetry (TRPIV) at a Reynolds number of 20,000 based on the disk diameter, both with and without control. An open-loop control was applied via periodic synthetic jet excitation from the disk edge. With the advantage of a time resolved velocity database, we have the ability to reconstruct the time dependent velocity field in the wake of the disk. This reconstruction is done for the baseline and controlled cases using various POD truncations to observe velocity reconstructions, based on the overall energy of the system. In doing so, we will consider the convergence rate of the spatial eigenvalues when conducting our POD reconstruction of the fluctuating velocity field, for both the baseline and controlled cases. Since a complex flow exists in the wake of the disk, the goal will be to form a state space representation of the flow in the form of a linear time invariant (LTI) system. This model is simply a linearization of the flow around the baseline. Furthermore, our knowledge of the input control signal will allow us to predict the flow at a later instant in time. We would like to extract the most energetic modes of the system and thereby form our observer-based controller to close the loop. In order to accomplish this, and with a rich open-loop dataset at our disposal, we will first form the POD reconstruction of the baseline. We then form a new basis, obtained by taking the actuated (controlled) data and subtracting from it the components of the flow that fall in the subspace spanned by the baseline flow. This will characterize the flow field by capturing the effect of the control input (actuation), from which the parameters of the LTI system can be identified. Preliminary POD reconstruction shows that 60% of the energy is recovered from 20 POD modes of the total 511 modes for the baseline case; similarly 60% of the energy is also recovered from 100 POD modes of the total 1,024 modes for the actuated case.

Integrated Rotor Performance Improvement and Vibration Reduction Using Active Camber Morphing

2019 ◽  
Author(s):  
Sumeet Kumar ◽  
Dominik Komp ◽  
Manfred Hajek ◽  
Jürgen Rauleder
Keyword(s):  
Active Control ◽  
Closed Loop ◽  
Vibration Reduction ◽  
Fish Bone ◽  
Open Loop ◽  
Beam Elements ◽  
Line Theory ◽  
Wake Model ◽  
Lifting Line ◽  
Lifting Line Theory

Abstract This paper discusses open-loop and closed-loop active control investigations of a full-scale Bo 105 helicopter rotor with active camber morphing. The potential of an active camber morphing concept to reduce non-rotating vibratory hub loads and rotor power using active control was investigated. The mechanism employed was a dynamically actuated airfoil camber morphing concept known as Fish Bone Active Camber (FishBAC) that smoothly deforms the camber over the aft section of the airfoil. A comprehensive rotorcraft aeromechanics analysis was used that modeled the blade elastic motion using one-dimensional finite beam elements combined with multibody dynamics. Aerodynamic forces were calculated with a free-vortex wake model together with lifting line theory for the blade aerodynamics. The open-loop investigation comprised of a parametric study of relevant control parameters that govern the active camber deflection cyclic actuation profile and their effects on rotor performance and hub vibration. It was found that active camber morphing using superimposed once-per-revolution (1P) and 2P control inputs was able to simultaneously reduce rotor power by 4.3% and overall vibratory hub loads by 27%. Additionally, a closed-loop adaptive multicyclic controller was used to identify the potential of this morphing concept for hub vibration reduction using multicyclic active control inputs. Active camber actuation using a sum of four control harmonic inputs, i.e. 1-4P, resulted in a maximum hub vibration reduction of 50%.

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