Fluidic Control Method for Improving the Self-Starting Ability of Hypersonic Inlets

2016 ◽  
Vol 32 (1) ◽  
pp. 153-160 ◽  
Author(s):  
Jian-Yong Wang ◽  
Lv-Rong Xie ◽  
Hao Zhao ◽  
Yu-Lin Teng ◽  
Guang-Fu Ma
Keyword(s):  
Control Method ◽  
The Self ◽  
Fluidic Control ◽  
Hypersonic Inlets

Bleeding Control for Improving Internal Waverider Inlet Self-Starting ability

2019 ◽  
Vol 36 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Zuo Fengyuan ◽  
Huang Guoping ◽  
Xia Chen
Keyword(s):  
Numerical Simulation ◽  
High Performance ◽  
Control Mechanism ◽  
Control Method ◽  
Separation Bubble ◽  
Three Dimensional ◽  
The Self ◽  
Bleeding Control ◽  
Fluidic Control ◽  
The Impact

Abstract Internal waverider inlets (IWIs) are novel three-dimensional (3D) high-performance inward turning inlets. However, they possess poor self-starting capacity when applied in a fixed-geometry inlet for ramjets. Firstly, this paper presents an analysis of self-starting capacity for IWIs to demonstrate that IWIs face more difficult challenges when used as ramjet inlets than they do as scramjet inlets. Self-starting capacity must be taken into account when designing ramjet inlets. Secondly, the impact of a fluidic control method on a fixed-geometry IWI was studied by numerical simulation of fluid flow. The numerical results show that the fluidic control mechanism improved the self-starting capacity of the IWI at low Mach numbers: the minimum Mach number of self-starting capacity was reduced from M3.8 to M3.2; furthermore, the compression ratio was increased from 29.9 with no fluidic control to 31.9. By analyzing two different groups of fluidic control positions, it was determined that bleeding before the separation bubble has no impact on the IWI self-starting capacity.

Stabilization of a flexible pipe conveying fluid with an active boundary control method

2020 ◽  
Vol 26 (19-20) ◽  
pp. 1824-1834
Author(s):  
Beiming Yu ◽  
Hiroshi Yabuno ◽  
Kiyotaka Yamashita
Keyword(s):  
Flow Velocity ◽  
Control Method ◽  
Bending Moment ◽  
The Self ◽  
Pipe Conveying Fluid ◽  
Stabilization Method ◽  
Critical Flow Velocity ◽  
Complex Eigenvalues ◽  
Excited Oscillation ◽  
Conveying Fluid

A method of stabilizing the self-excited oscillation of a cantilevered pipe conveying fluid because of non–self-adjointness is proposed theoretically and experimentally. Complex eigenvalues denoting the natural frequency and damping of the system vary with an increase in the flow velocity. When the flow velocity exceeds a critical value, the flow-generated damping becomes negative and the pipe is dynamically destabilized. The complex eigenvalues with respect to flow velocity are affected by boundary conditions. We, thus, propose a stabilization control actuating the boundary condition. The stabilization method is carried out by applying a bending moment proportional to the bottom displacement of the pipe. The effect of the proposed control method is shown by investigating the stability for the three lowest modes of the system depending on the feedback gain. It is theoretically clarified that the critical flow velocity is increased by the proposed control method. Furthermore, experiments are performed using a fluid conveying pipe with two piezoactuators at the downstream end. The piezoactuators apply a bending moment at the downstream end of the pipe according to the theoretically proposed method. Experimental results verify that the proposed stabilization method suppresses the self-excited oscillation.

Design and Realization of Two-Axis Horizontal Stabilized Platform Based on Self-Correction Control Method

2012 ◽  
Vol 152-154 ◽  
pp. 1276-1280
Author(s):  
Chang Song Qi ◽  
Hong Jun Pan ◽  
Yan Le Wang
Keyword(s):  
Real Time ◽  
Control Method ◽  
The Self ◽  
Zero Drift ◽  
System Error ◽  
The Real ◽  
Stabilized Platform ◽  
Platform System ◽  
Horizontal Stabilization ◽  
The Way

To enhance the accuracy of stabilization, this paper presents a design of two-axis horizontal stabilization platform system, which is based on the combination of gyroscope and inclinometer sensors. The self-correction control method is put forward to solve the system error caused by gyroscope zero drift in traditional gyro stabilized platform, which works in the way of revising the gyroscope zero coefficient, according to the real-time attitude information feed backed by inclinometer sensors fixed in objective platform.

Control Method for Elimination of Self–Excited Oscillations during Turning

2010 ◽  
Vol 164 ◽  
pp. 171-176 ◽  
Author(s):  
Tomáš Březina ◽  
Jan Vetiška ◽  
Petr Blecha ◽  
Pavel Houška
Keyword(s):  
Tool Wear ◽  
Computer Model ◽  
Pid Controller ◽  
Control Method ◽  
The Self ◽  
Machining Process ◽  
Geometric Accuracy ◽  
Turning Process ◽  
Machined Surface ◽  
Excited Oscillation

The oscillations occurring between the tool and the machined area during the turning process lead to degradation of the machined surface, cause poor geometric accuracy, accelerate tool wear and generate noise. This paper deals with the possibility of elimination of these self-excited oscillations by changing the parameters of the turning process. On the basis of the regenerative principle of self-excited oscillation generation, a computer model of the machining process was developed. Furthermore, a PID controller was proposed to control the compensation of the vibrations and its suitability for elimination of the self-excited oscillations was verified experimentally.

A novel fluidic control method for nanofluidics by solvent–solvent interaction in a hybrid chip

Lab on a Chip ◽  
2015 ◽  
Vol 15 (4) ◽  
pp. 1004-1008 ◽  
Author(s):  
Guangchun Fu ◽  
Zezhi Zheng ◽  
Xin Li ◽  
Yue Sun ◽  
Hong Chen
Keyword(s):  
Control Method ◽  
Phase Interface ◽  
Two Phase ◽  
Solvent Interaction ◽  
Fluidic Control ◽  
Solvent Solvent

A fluidic control method for nanofluidics is realized by the interaction between the solvents at the two-phase interface.

Numerical Study on Scale Effect of KCS

2019 ◽  
Author(s):  
Yujie Zhou ◽  
Liwei Liu ◽  
Xiao Cai ◽  
Dakui Feng ◽  
Bin Guo
Keyword(s):  
Scale Effect ◽  
Degrees Of Freedom ◽  
Control Method ◽  
Numerical Study ◽  
The Body ◽  
The Self ◽  
Body Motion ◽  
Propulsion Performance ◽  
Calm Water ◽  
Unsteady Rans

Abstract The key objective of this paper is to perform a fully nonlinear unsteady RANS simulation to predict the self-propulsion performance of KCS at two different scales. This simulations are performed at design speeds in calm water, using inhouse computational fluid dynamics (CFD) to solve RANS equation coupled with two degrees of freedom (2DOF) solid body motion equations including heave and pitch. The SST k-ω turbulence equation is discretized by finite difference method. The velocity pressure coupling is solved by PISO algorithm. Computations have used structured grid with overset technology. The single-phase level-set method is used to capture the free surface. The simulations of self-propulsion are based on the body-force method. The PID control method is applied to match the speed of KCS by changing the propeller rotation speed automatically. In this paper, the self-propulsion factors of KCS at two scales are predicted and the results from inhouse CFD code are compared with the EFD date, and then the reasons for the scale effect have been discussed.

Stabilization of Self-Excited Oscillation in a Flexible Fluid-Conveying-Pipe by Position Feedback Control

2012 ◽  
Author(s):  
Hideaki Kosaki ◽  
Hiroshi Yabuno
Keyword(s):  
Control Method ◽  
Unstable Mode ◽  
Adjoint System ◽  
The Self ◽  
Flexible Pipe ◽  
Stabilization Control ◽  
Position Feedback ◽  
Excited Oscillation ◽  
Excitation Mechanisms ◽  
Points Of View

Resonances in flexible fluid-conveying-pipes have been theoretically and experimentally analyzed from the practical and physical points of view. The excitation mechanisms for the resonances have been given considerable attention. In contrast with the analysis of the resonance phenomena, there are few studies on the stabilization control method for the self-excited oscillation of a flexible fluid-conveying-pipe. In this paper, we propose a control method for the self-excited oscillation in a fluid-conveying-pipe theoretically and experimentally. The unstable mode of the fluid-conveying-pipe is not any eigenmodes of the flexible pipe without flow because it is non-self adjoint system. In this paper, by not using the eigenmodes of the flexible pipe without flow deriving the unstable mode shape exactly, we propose a stabilization control method which actuates the unstable mode directly. Therefore, under the proposed control method, the spillover is avoidable and only one sensor is required.

A Coordination Control Method of Generator Out-of-Step Protection Based on WAMS Transient Stability Prediction

2014 ◽  
Vol 568-570 ◽  
pp. 1811-1815
Author(s):  
Guo Lin Huang ◽  
Yan Jun Zhang ◽  
Zhao Chen ◽  
Peng Zhao ◽  
Qing Wang ◽  
...  
Keyword(s):  
Transient Stability ◽  
Control Method ◽  
Excess Energy ◽  
The Self ◽  
Protection Device ◽  
Stability Prediction ◽  
Coordination Control ◽  
Diagram Method ◽  
The Stability ◽  
Grid Side

The construction of ultra-high voltage grid and the input of large generating units make the out-of-step protection become increasingly important. Traditional out-of-step protection device can only judge from local perspective, no consideration to the global situation. In order to solve this problem, a coordination control method of generator out-of-step protection based on WAMS transient stability prediction is proposed, the coordination between grid side out-of-step protection and the generator out-of-step protection is achieved. Using the self-memory trajectory to predict the stability of grid, calculate excess energy of system based on EEAC theory, and utilize convexity-concavity of phase diagram method which is not affected by the change of network structure to judge the stability of system. Utilize double forecast strategy to improve the stability of the system further.

The Principle and System Design of Self-Cleaning Filter

2011 ◽  
Vol 383-390 ◽  
pp. 2550-2555
Author(s):  
Wei Sheng Liu ◽  
Zhi Qin Huang
Keyword(s):  
Software Design ◽  
Control Method ◽  
The Self ◽  
Transmission Control ◽  
Time Control ◽  
Filter Structure ◽  
Process Pressure ◽  
Pressure Transmission ◽  
Self Cleaning ◽  
Sewage Systems

This paper describes the self-cleaning filter structure, working principal and the main parameters, and it describes the hardware, control theory and software design process. Pressure transmission control method, time control, automatically open and close cleaning and sewage systems are used in automatic self-cleaning filter, which fully realizes unmanned operation, stable and reliable. There are some reference values in this article for the depth understanding of design and development the automatic cleaning filters.

Study on The Self-Adaptive Forecast and Optimal Control Method for Grinding Wheel Infeed

2007 ◽  
Vol 329 ◽  
pp. 87-92
Author(s):  
Gui Jie Liu ◽  
Ning Mei ◽  
Ya Dong Gong ◽  
Wan Shan Wang
Keyword(s):  
Optimal Control ◽  
Computer Simulation ◽  
Control Method ◽  
The Self ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Optimal Control Method ◽  
Grinding System ◽  
Self Adaptive

A self-adaptive forecast & optimal control method for grinding wheel in-feed is presented, it can control grinding wheel plunge by using the new program of grinding process, and can compensate availably the size errors produced by the elasticity deflection of the grinding system and the deference of work-pieces rough and the wear of the grinding wheel, et al. The result of computer simulation and real testing indicate that this method can improve grinding quality.

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