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.

scholarly journals Synchronization and Anti-Synchronization of Two Identical Hyperchaotic Systems Based on Active Backstepping Design

2011 ◽  
pp. 117-122
Author(s):  
Atefeh Saedian ◽  
Hassan Zarabadipoor
Keyword(s):  
Numerical Simulations ◽  
Active Control ◽  
Chaos Control ◽  
Control Method ◽  
Design Method ◽  
Backstepping Design ◽  
Backstepping Technique ◽  
Control Approach ◽  
Hyperchaotic Systems

This paper presents an active backstepping design method for synchronization and anti-synchronization of two identical hyperchaotic Chen systems. The proposed control method, combining backstepping design and active control approach, extends the application of backstepping technique in chaos control. Based on this method, different combinations of controllers can be designed to meet the needs of different applications. Numerical simulations are shown to verify the results.

Seismic Response Control for Four High-Rise Building Structures Using Connected Control Method

2007 ◽  
Author(s):  
Kazuto Seto ◽  
Chinori Iio ◽  
Shigeru Inaba ◽  
Shingo Mitani ◽  
Fadi Dohnal ◽  
...  
Keyword(s):  
Seismic Response ◽  
Active Control ◽  
Control Method ◽  
Control Force ◽  
Building Structures ◽  
Response Control ◽  
Control Approach ◽  
Seismic Response Control ◽  
High Rise ◽  
Lq Control

This paper presents a vibration control method for multiple high-rise buildings against large earthquake motion. This method is called as “Connected Control Method (CCM)” and has the merit of obtaining enough control force to protect high-rise buildings from large earthquakes using passive and semiactive devices. In this paper, first a modeling approach for four scaled building structures is shown and effectiveness of the CCM using LQ control approach for them is demonstrated by seismic response control results. Next, in order to reduce the supplied power, a semi-active control approach in place of active control is applied for the CCM. For this purpose, a new MR damper is developed and designed to have a close performance with results of the LQ control. This performance is verified by measured frequency responses.

scholarly journals Cooperative Control Method of Active and Semiactive Control: New Framework for Vibration Control

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Kazuhiko Hiramoto
Keyword(s):  
Vibration Control ◽  
Active Control ◽  
Cooperative Control ◽  
Control Method ◽  
Design Method ◽  
Control Object ◽  
Control Device ◽  
Semiactive Control ◽  
Control Input ◽  
Control Approach

A new control design framework for vibration control, the cooperative control of active and semiactive control, is proposed in the paper. In the cooperative control, a structural system having both of an actuator and a semiactive control device, for example, MR damper and so forth, is defined as the control object. In the proposed control approach, the higher control performance is aimed by the cooperative control between the active control with the actuator and the semiactive control with the semiactive control device. A design method to determine the active control input and the command signal to drive the semiactive control device based on the one-step prediction of the control output is proposed. A simulation example of a control system design for a benchmark building is presented to show the effectiveness of the proposed control framework.

scholarly journals Research and Analysis of Damping Control Technology in Civil Engineering Construction Process

2014 ◽  
Vol 8 (1) ◽  
pp. 406-406
Author(s):  
Yonggang Bao ◽  
Qingwei Meng ◽  
Ki Bae Seo
Keyword(s):  
Active Control ◽  
Passive Control ◽  
Civil Engineering ◽  
Control Method ◽  
Rapid Development ◽  
Rational Approach ◽  
Engineering Structures ◽  
Engineering Construction ◽  
Engineering Structure ◽  
Civil Engineering Structure

With the rapid development of society and the economy, people's life and property safety importance is also more and more high. Especially the occurrence of the Wenchuan earthquake, people on whether the application of civil engineering construction damping scientific and rational approach was questioned. How to ensure the quality of civil engineering construction, to avoid in the event of earthquakes and other natural disasters, the emergence floor crash event, is an issue for all engineering designers and builders focus on. Because of the relationship with all life safety, so how to use rational scientific method damping to the construction of civil engineering structures is very important and necessary. This study from the passive control, active control, semi-active control and hybrid control methods start with four damping research and analysis, combining their research status. The Benchmark problem of structure control has carried on the simple introduction. Focusing on civil engineering structure vibration control method of systematic review, so as to the future of civil engineering structure suspension construction provides the certain reference function

The Optimal Control Method of Impulse Response in Prosthetic Leg

2014 ◽  
Vol 915-916 ◽  
pp. 1181-1185
Author(s):  
Xin Yi Xiao ◽  
Han Bin Xiao
Keyword(s):  
Optimal Control ◽  
Active Control ◽  
Impulse Response ◽  
Passive Control ◽  
Control Method ◽  
Control Variable ◽  
The Body ◽  
Control Techniques ◽  
Suspension Systems ◽  
Optimal Control Method

Passive control and semi-active control of vibration in mechanical systems have recently successfully been used in automobiles and airplanes suspension systems. These control techniques are able to guarantee the performances of all vibration structures. Unfortunately, the knowledge and data has not been readily applied to human prosthetics. The information collected can be directly applied to accelerate research into dampening for prosthetics. A focus of this paper is on modeling and controlling vibrations by a given impulse onto prosthetic legs. Simulations of using passive control and idealized skyhook dampening are using Matlab to complete. Through model analysis, control variable, simulation procedures and comparison of two modeling, the models have been refined and with idealized skyhook dampening suspension provide significant improvement of the body characteristics compared with passive suspensions.

Active Control of Fluid Pressure Pulsation in Hydraulic Pipe System by Bilateral-Overflow of Piezoelectric Direct-Drive Slide Valve

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Guan Changbin ◽  
Jiao Zongxia ◽  
Wu Shuai ◽  
Shang Yaoxing ◽  
Zheng Fanggang
Keyword(s):  
Active Control ◽  
High Speed ◽  
Pressure Pulsation ◽  
Control Method ◽  
Fluid Pressure ◽  
Slide Valve ◽  
Single Frequency ◽  
Direct Drive ◽  
Dual Frequency ◽  
Pipe System

In this paper, a novel active control of fluid pressure pulsation (ACFPP) is proposed, which meets the need of the high-pressure and high-speed hydraulic pipe system. A piezoelectric direct-drive slide valve (PDDSV) is designed and used as the active vibration absorber. Two ports of the PDDSV both connect to a bypass near the pump outlet and the other two ports both connect to the oil tank. By the bilateral-overflow through the shoulder of the PDDSV, the overflow wave generated in one cycle of spool motion can cancel two cycles of flow ripple. An adaptive-optimum control method based on the rotate-vector optimization method (RVOM) is adopted to adjust the control parameters in order to minimize the amplitude of the pressure pulsation. The biggest advantage of the proposed ACFPP is that it can eliminate the pressure pulsation when PDDSV only works at half of the pressure pulsation's frequency. The simulation and experimentation both verify the proposed ACFPP. By the proposed ACFPP, the suppression for the single-frequency component and dual-frequency components of the pressure pulsation have been both realized.

scholarly journals Enhanced remote astronomical archive system based on the file-level Unlimited Sliding-Window technique

2021 ◽  
Vol 21 (10) ◽  
pp. 253
Author(s):  
Cong-Ming Shi ◽  
Hui Deng ◽  
Feng Wang ◽  
Ying Mei ◽  
Shao-Guang Guo ◽  
...  
Keyword(s):  
Flow Control ◽  
Control Method ◽  
Sliding Window ◽  
Radio Observation ◽  
Observation Data ◽  
Bandwidth Utilization ◽  
Data Archiving ◽  
Control Approach ◽  
Archive System ◽  
Communication Time

Abstract Data archiving is one of the most critical issues for modern astronomical observations. With the development of a new generation of radio telescopes, the transfer and archiving of massive remote data have become urgent problems to be solved. Herein, we present a practical and robust file-level flow-control approach, called the Unlimited Sliding-Window (USW), by referring to the classic flow-control method in the TCP protocol. Based on the USW and the Next Generation Archive System (NGAS) developed for the Murchison Widefield Array telescope, we further implemented an enhanced archive system (ENGAS) using ZeroMQ middleware. The ENGAS substantially improves the transfer performance and ensures the integrity of transferred files. In the tests, the ENGAS is approximately three to twelve times faster than the NGAS and can fully utilize the bandwidth of network links. Thus, for archiving radio observation data, the ENGAS reduces the communication time, improves the bandwidth utilization, and solves the remote synchronous archiving of data from observatories such as Mingantu spectral radioheliograph. It also provides a better reference for the future construction of the Square Kilometer Array (SKA) Science Regional Center.

Hybrid vibro-acoustic active control method for vehicle interior sound quality under high-speed

2022 ◽  
Vol 186 ◽  
pp. 108419
Author(s):  
X.L. Wang ◽  
Y.C. Song ◽  
T.Z. Wang ◽  
Y.S. Wang ◽  
N.N. Liu
Keyword(s):  
Active Control ◽  
High Speed ◽  
Control Method ◽  
Sound Quality ◽  
Vehicle Interior ◽  
Active Control Method

Passive boundary layer control of oblique disturbances by finite-amplitude streaks

2014 ◽  
Vol 749 ◽  
pp. 1-36 ◽  
Author(s):  
Shahab Shahinfar ◽  
Sohrab S. Sattarzadeh ◽  
Jens H. M. Fransson
Keyword(s):  
High Speed ◽  
Passive Control ◽  
Control Method ◽  
Three Dimensional ◽  
Finite Amplitude ◽  
Transition To Turbulence ◽  
Spanwise Direction ◽  
Passive Flow Control ◽  
Tollmien Schlichting ◽  
Streamwise Streaks

AbstractRecent experimental results on the attenuation of two-dimensional Tollmien–Schlichting wave (TSW) disturbances by means of passive miniature vortex generators (MVGs) have shed new light on the possibility of delaying transition to turbulence and hence accomplishing skin-friction drag reduction. A recurrent concern has been whether this passive flow control strategy would work for other types of disturbances than plane TSWs in an experimental configuration where the incoming disturbance is allowed to fully interact with the MVG array. In the present experimental investigation we show that not only TSW disturbances are attenuated, but also three-dimensional single oblique wave (SOW) and pair of oblique waves (POW) disturbances are quenched in the presence of MVGs, and that transition delay can be obtained successfully. For the SOW disturbance an unusual interaction between the wave and the MVGs occurs, leading to a split of the wave with one part travelling with a ‘mirrored’ phase angle with respect to the spanwise direction on one side of the MVG centreline. This gives rise to $\Lambda $-vortices on the centreline, which force a low-speed streak on the centreline, strong enough to overcome the high-speed streak generated by the MVGs themselves. Both these streaky boundary layers seem to act stabilizing on unsteady perturbations. The challenge in a passive control method making use of a non-modal type of disturbances to attenuate modal disturbances lies in generating stable streamwise streaks which do not themselves break down to turbulence.

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