Modeling and Feedback Structural Acoustics Control of a Flexible Plate

2000 ◽  
Vol 123 (1) ◽  
pp. 18-23 ◽  
Author(s):  
Kazuto Seto ◽  
Mingzhang Ren ◽  
Fumio Doi
Keyword(s):  
State Space ◽  
Physical State ◽  
Lumped Parameter Model ◽  
Optimal Controller ◽  
Flexible Plate ◽  
Structural Acoustics ◽  
Reduced Order ◽  
Distributed Parameters ◽  
Lumped Parameter ◽  
High Sound

A lumping method via an inverse modal analysis approach is proposed in this paper for creating a lumped parameter model for a structure with distributed parameters. On the basis of the lumped parameter model, the formulation of an optimal controller in physical state space is presented and, furthermore, the design of a reduced-order controller is described. The method is demonstrated and verified by the vibration and noise control experiments carried out on a clamped plate. Several modes of the plate with high sound radiating efficiencies are well controlled by using three sensors and one actuator, based on a 9 degree-of-freedom (DOF) lumped parameter model of the plate.

Modeling and Feedback Control of Flexible Plate With Focus on the Modes Highly Coupled to Radiation Field

1997 ◽  
Author(s):  
Mingzhang Ren ◽  
Kazuto Seto ◽  
Fumio Doi
Keyword(s):  
Sound Radiation ◽  
Lumped Parameter Model ◽  
Control Law ◽  
Vibration Modes ◽  
Flexible Plate ◽  
Structural Acoustics ◽  
Actual Structure ◽  
Lumped Model ◽  
Analysis Process ◽  
Lumped Parameter

Abstract A discretization method based on an inverse modal analysis process is presented for creating a lumped parameter model for actual structure. With the discrete system the standard optimal control law can be formulated in physical state space to design a controller. Furthermore, the method makes it easy to target the vibration modes with prominent sound radiation in control design, that is a simplified consideration of active structural acoustics control. The method is demonstrated and verified by vibration and noise control experiments of a clamped plate. Four highly radiating modes among the first twelve modes of the plate are well controlled by using three sensors and one actuator, based on a 9DOF lumped model of the plate.

The Mechanism on Prediction of Transient Maximum Amplitude for Tuned and Mistuned Blisks

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Luohui Ouyang ◽  
Hai Shang ◽  
Hua Chen ◽  
Qingzhen Bi ◽  
Li-Min Zhu
Keyword(s):  
Damping Ratio ◽  
Maximum Amplitude ◽  
Element Model ◽  
Forced Response ◽  
Lumped Parameter Model ◽  
Fundamental Parameter ◽  
Reduced Order ◽  
Lumped Parameter ◽  
Engine Order ◽  
Acceleration And Deceleration

Abstract Blisks are subjected to frequent acceleration and deceleration, which leads to a transient forced response; however, there is limited understanding of this response. In this work, the mechanism on prediction of transient maximum amplitude is found. An analytical link is proposed between the transient maximum amplitude and a fundamental dimensionless parameter which combines the damping ratio, natural frequency, acceleration, and engine order of the system to reveal the mechanism of the transient maximum amplitude. Therefore, the transient maximum amplitudes of tuned and mistuned blisks are predicted analytically. First, a lumped parameter model is used to study the mechanism of the transient maximum amplitude for a tuned blisk, and an approximated analytical expression is derived between the fundamental parameter and the transient amplification factor of a 1DOF (degree-of-freedom) model. The relationship is also applicable to a reduced order, tuned finite element model (FEM). Second, the mechanism of the transient response for a mistuned blisk is studied in the decoupled modal space of the blisk, based on the 1DOF transient relationship. The transient maximum amplitude in a reduced order, mistuned FEM is predicted. Two lumped parameter models and a FEM are employed to validate the prediction.

The Modeling and Active Control of Flexible Plate Structure for Reducing Noise Radiation

1995 ◽  
Author(s):  
Kazuto Seto ◽  
Takaharu Miyata ◽  
Mingzhang Ren ◽  
Fumio Doi
Keyword(s):  
Control Theory ◽  
Active Vibration Control ◽  
Lumped Parameter Model ◽  
Suboptimal Control ◽  
Flexible Plate ◽  
Radiated Noise ◽  
Plate Structure ◽  
Lumped Parameter ◽  
Active Vibration ◽  
Strategy Design

Abstract This paper shows a new method of active vibration control of a flexible plate structure with aim to reduce the radiated noise. It involves modeling the real structure into a reduced order lumped parameter model on the basis of modal analysis, and then adopting LQ control theory to control the vibration of selected multi-modes of the plate. In this paper the modeling procedure and the control strategy design is presented, in which suboptimal control theory and digital filtering technique have been used. Simulation and preliminary experimental results are given to demonstrate the effectiveness of the proposed method.

scholarly journals A New Lumped Parameter Model for Natural Gas Pipelines in State Space

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1971 ◽  
Author(s):  
Kai Wen ◽  
Zijie Xia ◽  
Weichao Yu ◽  
Jing Gong
Keyword(s):  
Natural Gas ◽  
State Space ◽  
Transient Flow ◽  
Transfer Functions ◽  
The State ◽  
Lumped Parameter Model ◽  
Actual Behavior ◽  
Gas Pipelines ◽  
Computational Point ◽  
Lumped Parameter

Many algorithms and numerical methods, such as implicit and explicit finite differences and the method of characteristics, have been applied for transient flow in gas pipelines. From a computational point of view, the state space model is an effective method for solving complex transient problems in pipelines. However, the impulse output of the existing models is not the actual behavior of the pipeline. In this paper, a new lumped parameter model is proposed to describe the inertial nature of pipelines with inlet/outlet pressure and flow rate as outer variables in the state space. Starting from the basic mechanistic partial differential equations of the general one-dimensional compressible gas flow dynamics under isothermal conditions, the transfer functions are first acquired as the fundamental work. With Taylor-expansion and a transformation procedure, the inertia state space models are derived with proper simplification. Finally, three examples are used to illustrate the effectiveness of the proposed model. With the model, a real-time automatic scheduling scheme of the natural gas pipeline could be possible in the future.

scholarly journals A Distributed Lumped Parameter Model of Blood Flow

2020 ◽  
Vol 48 (12) ◽  
pp. 2870-2886
Author(s):  
Mehran Mirramezani ◽  
Shawn C. Shadden
Keyword(s):  
Blood Flow ◽  
Lumped Parameter Model ◽  
Lumped Parameter
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