Linear and passive control method for the steady state amplitude in a parametrically excited hinged-hinged beam

2014 ◽  
Vol 2 ◽  
pp. 26-29
Author(s):  
Hiroshi YABUNO ◽  
Hajime OHISHI
Keyword(s):  
Steady State ◽  
Passive Control ◽  
Control Method ◽  
Parametrically Excited ◽  
Steady State Amplitude

Disorganization of a hole tone feedback loop by an axisymmetric obstacle on a downstream end plate

2014 ◽  
Vol 757 ◽  
pp. 908-942 ◽  
Author(s):  
K. Matsuura ◽  
M. Nakano
Keyword(s):  
Nozzle Exit ◽  
Passive Control ◽  
Control Method ◽  
Three Dimensional ◽  
Acoustic Power ◽  
Shear Layers ◽  
Mean Velocity ◽  
End Plate ◽  
Air Jet ◽  
Practical Engineering

AbstractThis study investigates the suppression of the sound produced when a jet, issued from a circular nozzle or hole in a plate, goes through a similar hole in a second plate. The sound, known as a hole tone, is encountered in many practical engineering situations. The mean velocity of the air jet $\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}u_0$ was $6\text {--}12\ \mathrm{m}\ {\mathrm{s}}^{-1}$. The nozzle and the end plate hole both had a diameter of 51 mm, and the impingement length $L_{im}$ between the nozzle and the end plate was 50–90 mm. We propose a novel passive control method of suppressing the tone with an axisymmetric obstacle on the end plate. We find that the effect of the obstacle is well described by the combination ($W/L_{im}$, $h$) where $W$ is the distance from the edge of the end plate hole to the inner wall of the obstacle, and $h$ is the obstacle height. The tone is suppressed when backflows from the obstacle affect the jet shear layers near the nozzle exit. We do a direct sound computation for a typical case where the tone is successfully suppressed. Axisymmetric uniformity observed in the uncontrolled case is broken almost completely in the controlled case. The destruction is maintained by the process in which three-dimensional vortices in the jet shear layers convect downstream, interact with the obstacle and recursively disturb the jet flow from the nozzle exit. While regions near the edge of the end plate hole are responsible for producing the sound in the controlled case as well as in the uncontrolled case, acoustic power in the controlled case is much lower than in the uncontrolled case because of the disorganized state.

scholarly journals A Critical Review of Supersonic Flow Control for High-Speed Applications

2021 ◽  
Vol 11 (15) ◽  
pp. 6899
Author(s):  
Abdul Aabid ◽  
Sher Afghan Khan ◽  
Muneer Baig
Keyword(s):  
Supersonic Flow ◽  
Flow Control ◽  
Active Control ◽  
Critical Review ◽  
High Speed ◽  
Passive Control ◽  
Control Method ◽  
Sudden Expansion ◽  
Control Approach ◽  
Cost Efficient

In high-speed fluid dynamics, base pressure controls find many engineering applications, such as in the automobile and defense industries. Several studies have been reported on flow control with sudden expansion duct. Passive control was found to be more beneficial in the last four decades and is used in devices such as cavities, ribs, aerospikes, etc., but these need additional control mechanics and objects to control the flow. Therefore, in the last two decades, the active control method has been used via a microjet controller at the base region of the suddenly expanded duct of the convergent–divergent (CD) nozzle to control the flow, which was found to be a cost-efficient and energy-saving method. Hence, in this paper, a systemic literature review is conducted to investigate the research gap by reviewing the exhaustive work on the active control of high-speed aerodynamic flows from the nozzle as the major focus. Additionally, a basic idea about the nozzle and its configuration is discussed, and the passive control method for the control of flow, jet and noise are represented in order to investigate the existing contributions in supersonic speed applications. A critical review of the last two decades considering the challenges and limitations in this field is expressed. As a contribution, some major and minor gaps are introduced, and we plot the research trends in this field. As a result, this review can serve as guidance and an opportunity for scholars who want to use an active control approach via microjets for supersonic flow problems.

Secure Communication with Chaos and Electronic Circuit Design Using Passivity-Based Synchronization

2017 ◽  
Vol 27 (04) ◽  
pp. 1850057 ◽  
Author(s):  
Uğur Erkin Kocamaz ◽  
Serdar Çiçek ◽  
Yılmaz Uyaroğlu
Keyword(s):  
Numerical Simulation ◽  
Circuit Design ◽  
Communication System ◽  
Secure Communication ◽  
Passive Control ◽  
Electronic Circuit ◽  
Control Method ◽  
Data Communication ◽  
Matlab Simulink ◽  
Electronic Circuit Design

This work deals with the passive control-based chaos synchronization with circuit design for secure communication. First, the numerical simulation and electronic circuit design of a simple five-term chaotic system are performed. The numerical simulation and electronic circuit design outputs have confirmed each other. Then, the passive control method is applied for synchronizing two identical five-term chaotic systems using only one state control signal. After the synchronization study, design and analysis for secure communication by chaotic masking method are conducted in Matlab–Simulink platform. Finally, an electronic circuit design is performed for the designed communication system. In the designed communication system with Matlab–Simulink platform and electronic circuit design, information signal which is sent from the transmitter unit is successfully retrieved at the receiver unit. As a result, the electronic circuit design has shown that a single state passivity-based synchronization signal can be effectively used for secure data communication applications for the real environment.

scholarly journals Research on Anti-saturation Feedback Control Method for UAV Avionics System

2018 ◽  
Vol 232 ◽  
pp. 04008
Author(s):  
Xiao-Jun Zhang
Keyword(s):  
Steady State ◽  
Control Method ◽  
Control Process ◽  
System Control ◽  
State Control ◽  
Saturation Control ◽  
Disturbance Rejection Control ◽  
Feedback Control Method ◽  
Equivalent Control ◽  
Steady State Control

UAV avionics system is prone to saturation distortion under unsteady conditions, so anti-saturation control is needed. A control method of UAV avionics system based on anti-saturation feedback compensation is proposed. The anti-saturation control process of UAV avionics system is a multi-objective optimization process with multi-variables. The constrained parameter model of UAV avionics system control is constructed. Electromagnetic loss, torque, output power and other parameters are taken as constraint indexes, the original control information of UAV avionics system is treated with self-stabilization, the equivalent control circuit is designed, and the magnetic resonance transmission mode of avionics system is analyzed. An anti-saturation feedback tracking control method is used for steady-state control of the output voltage of the avionics system. The error compensation function is constructed to adjust the output adaptive parameters of the avionics system and the static anti-saturation compensator is constructed to compensate the power gain. The yaw error and the output steady-state error of the avionics system are reduced. The simulation results show that the proposed method has better output stability, lower output error, better real-time performance and better linear auto-disturbance rejection control performance.

Free and Forced Longitudinal Vibrations of a Cantilevered Bar With a Crack

1992 ◽  
Vol 114 (2) ◽  
pp. 171-177 ◽  
Author(s):  
K. R. Collins ◽  
R. H. Plaut ◽  
J. Wauer
Keyword(s):  
Steady State ◽  
Natural Frequency ◽  
Transverse Crack ◽  
Breathing Crack ◽  
Longitudinal Vibrations ◽  
Harmonic Force ◽  
Frequency Spectra ◽  
Crack Location ◽  
Fundamental Natural Frequency ◽  
Steady State Amplitude

Longitudinal vibrations of a cantilevered bar with a transverse crack are investigated. For undamped, unforced vibrations, frequency spectra are computed and the effects of the crack location and compliance on the fundamental natural frequency are determined. For vibrations caused by a distributed, longitudinal, harmonic force, the steady-state amplitude of motion of the free end is plotted as a function of the forcing frequency, crack location, and crack compliance, and frequency spectra are also obtained. Results for a breathing crack are compared to those for a crack which remains open and those for an uncracked bar.

Composite Fuzzy Control Method for Temperature in Intelligent Moisture Analyzer

2013 ◽  
Vol 401-403 ◽  
pp. 1010-1013
Author(s):  
Jing Ling ◽  
Jin Che ◽  
Da Ming Liu
Keyword(s):  
Steady State ◽  
Fuzzy Control ◽  
Control Method ◽  
Fuzzy Controller ◽  
Time Lag ◽  
Threshold Value ◽  
National Standards ◽  
Infrared Heating ◽  
Temperature Control System ◽  
State Error

Temperature control system of infrared heating oven in moisture analyzer is characteristic of nonlinear, time-varying and time-lag. A composite fuzzy control (CFC) method is proposed, which combines improved Bang-Bang control with two-stage intelligent fuzzy control. The control algorithm is implemented by MSP430F5438. When the temperature error e between the desired temperature and actual temperature in heating oven is larger than threshold value, the improved Bang-Bang controller is employed in rapidly reducing the error; to decrease the system overshoot, the basic fuzzy controller is used; to reduce the steady-state error of basic fuzzy controller, the auxiliary fuzzy controller is applied. The steady-state error of improved fuzzy controller for oven temperature is less than 0.5°C, which is better than the Chinese National Standards for moisture content measurement.

Passive control of deep cavity shear layer flow at subsonic speed

2017 ◽  
Vol 95 (10) ◽  
pp. 894-899
Author(s):  
Mouhammad El Hassan ◽  
Laurent Keirsbulck
Keyword(s):  
Shear Layer ◽  
Passive Control ◽  
Control Method ◽  
Leading Edge ◽  
Layer Growth ◽  
Cavity Resonance ◽  
Passive Flow Control ◽  
Acoustic Coupling ◽  
Deep Cavity ◽  
Layer Flow

Passive control of the flow over a deep cavity at low subsonic velocity is considered in the present paper. The cavity length-to-depth aspect ratio is L/H = 0.2. particle image velocimetry (PIV) measurements characterized the flow over the cavity and show the influence of the control method on the cavity shear layer development. It is found that both the “cylinder” and the “shaped cylinder”, placed upstream from the cavity leading edge, result in the suppression of the aero-acoustic coupling and highly reduce the cavity noise. It should be noted that the vortical structures impinge at almost the same location near the cavity downstream corner with and without passive control. The present study allows to identify an innovative passive flow control method of cavity resonance. Indeed, the use of a “shaped cylinder” presents similar suppression of the cavity resonance as with the “cylinder” but with less impact on the cavity flow. The “shaped cylinder” results in a smaller shear layer growth than the cylinder. Velocity deficiency and turbulence levels are less pronounced using the “shaped cylinder”. The “cylinder” tends to diffuse the vorticity in the cavity shear layer and thus the location of the maximum vorticity is more affected as compared to the “shaped cylinder” control. The fact that the “shaped cylinder” is capable of suppressing the cavity resonance, despite the vortex shedding and the high frequency forcing being suppressed, is of high interest from fundamental and applied points of view.

Control of a Buckled Beam Subjected to a Compressive Force

2001 ◽  
Author(s):  
Hiroshi Yabuno ◽  
Kazuya Ando ◽  
Nobuharu Aoshima
Keyword(s):  
Steady State ◽  
Disturbance Observer ◽  
Coulomb Friction ◽  
Control Method ◽  
Compressive Force ◽  
Restoring Force ◽  
Velocity Feedback ◽  
Stabilization Control ◽  
Buckled Beam ◽  
Position Feedback

Abstract In this paper, we deal with a stabilization control for the buckled beam subjected to a compressive force. It is easily predicted that by applying a restoring force to the beam (P control), which is proportional to the deflection, the critical compressive force for the buckling is increased. However it is theoretically and experimentally clarified in our former study that in the neighborhood of the critical point, the effect of Coulomb friction at the supporting points is relatively increased even if it is very slight. It follows that the beam cannot be stabilized to the trivial steady state only by using the position feedback control and also velocity feedback. In this paper, we propose a stabilization control method of the beam to the trivial steady state by the aid of disturbance observer. Furthermore, the validity of the theoretically proposed method is experimentally confirmed.

HVAC System Energy Minimization via Optimization of Lumped System Models

2010 ◽  
Author(s):  
Aaron P. Wemhoff
Keyword(s):  
Steady State ◽  
Energy Savings ◽  
Control Method ◽  
The United States ◽  
New Method ◽  
Hvac System ◽  
Household Energy ◽  
Variable Air Volume ◽  
Load Distributions ◽  
Lumped Parameter

Heating, ventilating, and air conditioning (HVAC) systems comprise nearly one third of annual household energy consumption in the United States. Energy savings can be gained by optimizing HVAC performance using a system of controls. This study applies a novel control method towards a system with an arbitrary steady-state load distribution. The new method applies multi-dimensional interpolation of optimized control configurations for various steady-state load distributions. These optimal configurations are derived using a lumped parameter simulation of the HVAC system. The new method is applied to a three-room HVAC system to demonstrate a power savings of 40% compared to an uncontrolled system. These savings compare favorably to predictions using the Variable-Air-Volume (VAV) method (37% power savings) and VAV with chiller control (33% power savings).

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