Study of Flow Characteristics and Control Circuit on High-Speed Solenoid Valve

2012 ◽  
Vol 619 ◽  
pp. 107-110 ◽  
Author(s):  
Wen Hua Li ◽  
Wen Lin Shao
Keyword(s):  
High Speed ◽  
Flow Characteristics ◽  
Pulse Signal ◽  
Solenoid Valve ◽  
Control Circuit ◽  
Duty Ratio ◽  
Time Sharing ◽  
Small Current ◽  
Wide Range ◽  
And Control

Through the analysis of the flow characteristics of the high-speed solenoid valve, the conclusions that the PWM signal duty ratio is the main factor affecting the solenoid valve flow is obtained, a new available any PWM pulse signal and control circuit are proposed. Further, circuit schematic is simulated by means of SIMULINK tools in MATLAB environment and Verify its stability. A time-sharing drive circuit is design based on the PWM drive mode. The driver circuit have function which is high-current open, small current maintain. Open current and maintain current of Solenoid valve can be adjusted through this circuit. Therefore, the circuit can adapt to different parameters of the solenoid valve. A wide range of applications.

Research on Intelligent Actuation Control Technology of High-Speed Solenoid Valve

2014 ◽  
Vol 678 ◽  
pp. 388-391
Author(s):  
Yuan Chang ◽  
Guang Yao Ouyang ◽  
Zhen Ming Liu
Keyword(s):  
High Speed ◽  
Finite State Machine ◽  
Control Method ◽  
Low Voltage ◽  
Solenoid Valve ◽  
Control Circuit ◽  
Time Sharing ◽  
Current Feedback ◽  
Finite State ◽  
Common Rail Injector

In order to develop actuation circuit for high pressure common rail injector solenoid valve, the high and low voltage time-sharing actuation control method based on current feedback was researched. A finite state machine tool called stateflow was used to establish the actuation model of solenoid, and the intelligent actuation control circuit was developed according to the model and MCU. The driving current can be adjusted automatically according to “Peak-High-Low” three-stage current, and the circuit can troubleshoot the state of solenoid. Driving Experiments on solenoid and injector were carried out and the results show the good performance of the intelligent actuation control circuit.

Flow Characteristics of Rectangular Liquid Jets Injected Into Low Subsonic Crossflow

2019 ◽  
Author(s):  
M. Tadjfar ◽  
A. Jaberi ◽  
R. Shokri
Keyword(s):  
High Speed ◽  
Flow Characteristics ◽  
Combustion Efficiency ◽  
Liquid Jets ◽  
High Speed Photography ◽  
Aspect Ratios ◽  
Jet Trajectory ◽  
Wide Range ◽  
Circular Holes ◽  
Subsonic Crossflow

Abstract Perpendicular injection of liquid jets into gaseous crossflow is well-known as an effective way to obtain good mixing between liquid fuel and air crossflow. Mostly, injectors with circular holes were used as the standard method of fuel spraying. However, recently a great attention to injectors with non-circular holes has emerged that aims to improve the quality of fuel mixing and consequently combustion efficiency. In the present work, rectangular injectors with different aspect ratios varying from 1 to 4 were experimentally studied. Using a wind tunnel with maximum air velocity of 42 m/s, tests were performed for a wide range of flow conditions including liquid-to-air momentum ratios of 10, 20, 30 and 40. Backlight shadowgraphy and high speed photography were employed to capture the instantaneous physics of the liquid jets discharged into gaseous crossflow. The flow physics of the rectangular liquid jets were investigated by means of flow visualizations. Different regimes of flow breakup including capillary, arcade, bag and multimode were observed for rectangular jets. Moreover, a new technique was used to calculate the trajectory of the liquid jets. It was shown the nozzle’s shape has no significant effect on jet trajectory. Also, the momentum ratio was found to has a profound effect on jet trajectory.

Phenomenon of Fog Formation and Flow Characteristics of Droplet-Vapor-Gas Mixture in a Cooler-Condenser

2019 ◽  
Author(s):  
Hongfang Gu ◽  
Qiwei Guo ◽  
Changsong Li ◽  
Qing Zhou
Keyword(s):  
Experimental Data ◽  
Numerical Analysis ◽  
High Speed ◽  
Flow Characteristics ◽  
Saturation Temperature ◽  
Bulk Temperature ◽  
Dropwise Condensation ◽  
Operation Conditions ◽  
Droplet Transport ◽  
Wide Range

Abstract Fog formation occurs in the process of condensation in the presence of non-condensable gas if the bulk temperature is lower than its saturation temperature (supersaturated). The phenomena of fogging is the formation of small condensate particles mixing with the vapor/gas stream, which creates potential problems of the vapor/gas/condensate separation and environmental pollution. Therefore, understanding of fogging mechanism and prevention of fog droplet entrainment are one of technical concerns for design and operation of cooler-condensers in the process industry. This paper presents the experimental study and numerical simulation of shell-side condensation with fog formation using a mixture of steam/non-condensable gas. The experimental data were collected on the two tube bundles (modified plastic tubes and stainless steel tubes). Using a high-speed photograph technique, the phenomenon of fog formation and flow characteristics of vapor/droplet transport were recorded over a wide range of test conditions. The numerical analysis of film and dropwise condensation, fog formation and droplet particle transport were simulated using different tube geometry and material, and flow velocity of air/droplet mixture. Based on simulation results, a new droplet trapping parameter is proposed to assess the optimal parameters of heat exchanger structural and operation conditions. Comparisons show that the numerical analysis results have a good agreement with experimental data and observations. These findings provide fundamental approach to account for the effect of fog formation, film and dropwise condensation, and droplet transport crossflow in cooler-condensers.

Dynamic Analysis and Control of High Speed and High Precision Active Magnetic Bearings

1992 ◽  
Vol 114 (4) ◽  
pp. 623-633 ◽  
Author(s):  
K. Youcef-Toumi ◽  
S. Reddy
Keyword(s):  
Time Delay ◽  
High Speed ◽  
Dynamic Stiffness ◽  
Magnetic Bearing ◽  
Magnetic Bearings ◽  
Successful Operation ◽  
Highly Nonlinear ◽  
Wide Range ◽  
And Control ◽  
Digital Time

The successful operation of actively controlled magnetic bearings depends greatly on the electromechanical design and control system design. The function of the controller is to maintain bearing performance in the face of system dynamic variations and unpredictable disturbances. The plant considered here is the rotor and magnetic bearing assembly of a test apparatus. The plant dynamics consisting of actuator dynamics, rigid rotor dynamics and flexibility effects are described. Various components of the system are identified and their corresponding linearized theoretical models are validated experimentally. Tests are also run to identify the coupling effects and flexibility modes. The highly nonlinear behavior of the magnetic bearings in addition to the inherent instability of such a system makes the controller design complex. A digital Time Delay Controller is designed and its effectiveness evaluated using several simulations based on linear and nonlinear models for the bearing including bending mode effects. This controller is implemented as an alternative to an existing linear analog compensator. Several experiments are conducted with each controller for spinning and nonspinning conditions. These include time responses, closed loop frequency responses and disturbance rejection responses. The experimental results and comparisons between those of a digital Time Delay Controller and an analog compensator indicate that the Time Delay Controller has impressive static and dynamic stiffness characteristics for the prototype considered. The Time Delay Controller also maintains almost the same dynamic behavior over a significantly wide range of rotor speeds.

scholarly journals Efficient SMA Actuation—Design and Control Concepts

Proceedings ◽  
2020 ◽  
Vol 64 (1) ◽  
pp. 20
Author(s):  
Paul Motzki
Keyword(s):  
High Speed ◽  
Thermal Activation ◽  
Energy Savings ◽  
Form Factors ◽  
High Energy ◽  
Innovative Design ◽  
Wide Range ◽  
Millisecond Range ◽  
And Control ◽  
High Energy Consumption

The versatility of the form factors of thermal shape memory alloys (SMA) in combination with their unique actuation and sensing abilities allow for the design and construction of innovative multifunctional systems. Despite the considerable number of advantages, such as their exceptional energy density, only a few SMA-based actuator systems are commercially available. One of the main reasons for this is their inefficient thermal activation and the resulting high energy consumption. The efficiency of SMA-based actuator systems can be improved by innovative design and control approaches. In the first part of this paper, the intelligent combination of SMA actuator wires with bi-stable, nonlinear spring elements is described. This combination eliminates the commonly quoted disadvantages of SMAs—slow actuation and energy inefficiency—for a wide range of applications. In particular, two energy-free actuator configurations are realized, which can be applied to any non-proportional actuation tasks. The second approach for the realization of high-speed actuation and energy efficiency is the activation of SMA wires with high voltage pulses, which leads to actuation times in the millisecond range and energy savings of up to 80% in comparison to the suppliers’ recommendations. It is shown that even high AC voltages such as typical mains supplies can be directly used for highly efficient SMA activation.

New proposal of cylinder velocity control circuit by using PWM drive with high speed solenoid valve

2018 ◽  
Vol 2018 (0) ◽  
pp. YC2018-087
Author(s):  
Masaru KOUNO ◽  
Eiji MURAYAMA ◽  
Yukio KAWAKAMI ◽  
Akiyoshi HORIKAWA ◽  
Koji SHIOTA
Keyword(s):  
High Speed ◽  
Solenoid Valve ◽  
Control Circuit ◽  
Velocity Control

scholarly journals High-speed imaging of ice nucleation in water proves the existence of active sites

2019 ◽  
Vol 5 (2) ◽  
pp. eaav4316 ◽  
Author(s):  
Mark A. Holden ◽  
Thomas F. Whale ◽  
Mark D. Tarn ◽  
Daniel O’Sullivan ◽  
Richard D. Walshaw ◽  
...  
Keyword(s):  
High Speed ◽  
Active Sites ◽  
Complex Problem ◽  
Ice Nucleation ◽  
Crystal Formation ◽  
High Speed Imaging ◽  
Wide Range ◽  
Nanoscale Topography ◽  
Salient Factor ◽  
And Control

Understanding how surfaces direct nucleation is a complex problem that limits our ability to predict and control crystal formation. We here address this challenge using high-speed imaging to identify and quantify the sites at which ice nucleates in water droplets on the two natural cleavage faces of macroscopic feldspar substrates. Our data show that ice nucleation only occurs at a few locations, all of which are associated with micron-size surface pits. Similar behavior is observed on α-quartz substrates that lack cleavage planes. These results demonstrate that substrate heterogeneities are the salient factor in promoting nucleation and therefore prove the existence of active sites. We also provide strong evidence that the activity of these sites derives from a combination of surface chemistry and nanoscale topography. Our results have implications for the nucleation of many materials and suggest new strategies for promoting or inhibiting nucleation across a wide range of applications.

scholarly journals Internal flow characteristics in scaled pressure-swirl atomizer

2018 ◽  
Vol 180 ◽  
pp. 02059 ◽  
Author(s):  
Milan Malý ◽  
Marcel Sapík ◽  
Jan Jedelský ◽  
Lada Janáčková ◽  
Miroslav Jícha ◽  
...  
Keyword(s):  
High Speed ◽  
Laser Doppler Anemometry ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Liquid Sheet ◽  
Wide Range ◽  
Swirl Atomizer ◽  
Pressure Swirl ◽  
Pressure Swirl Atomizer ◽  
Working Liquid

Pressure-swirl atomizers are used in a wide range of industrial applications, e.g.: combustion, cooling, painting, food processing etc. Their spray characteristics are closely linked to the internal flow which predetermines the parameters of the liquid sheet formed at the discharge orifice. To achieve a better understanding of the spray formation process, the internal flow was characterised using Laser Doppler Anemometry (LDA) and high-speed imaging in a transparent model made of cast PMMA (Poly(methyl methacrylate)). The design of the transparent atomizer was derived from a pressure-swirl atomizer as used in a small gas turbine. Due to the small dimensions, it was manufactured in a scale of 10:1. It has modular concept and consists of three parts which were ground, polished and bolted together. The original kerosene-type jet A-1 fuel had to be replaced due to the necessity of a refractive index match. The new working liquid should also be colourless, non-aggressive to the PMMA and have the appropriate viscosity to achieve the same Reynolds number as in the original atomizer. Several liquids were chosen and tested to satisfy these requirements. P-Cymene was chosen as the suitable working liquid. The internal flow characteristics were consequently examined by LDA and high-speed camera using p-Cymene and Kerosene-type jet A-1 in comparative manner.

Learning From the Fins of Ray-Finned Fish for the Propulsors of Unmanned Undersea Vehicles

2011 ◽  
Vol 45 (4) ◽  
pp. 65-73 ◽  
Author(s):  
James L. Tangorra ◽  
Timo Gericke ◽  
George V. Lauder
Keyword(s):  
High Speed ◽  
The Body ◽  
External Disturbances ◽  
Pectoral Fins ◽  
Autonomous Regulation ◽  
Wide Range ◽  
Sensorimotor Systems ◽  
And Control ◽  
Vortex Perturbations

AbstractAdvanced propulsors are required to help unmanned undersea vehicles (UUVs) overcome major challenges associated with energy and autonomy. The fins of ray-finned fish provide an excellent model from which to develop propulsors that can create forces efficiently and drive a wide range of behaviors, from hover to low-speed maneuvers to high-speed travel. Although much is known about the mechanics of fins, little is known about the fin’s sensorimotor systems or how fins are regulated in response to external disturbances. This information is crucial for implementing propulsive and control systems that exploit the same phenomena as the biological fins for efficiency, effectiveness, and autonomous regulation. Experiments were conducted to evaluate the in vivo response of the sunfish and its pectoral fins to vortex perturbations applied directly to the fish and to the fins. The fish and the fins responded actively to perturbations that disturbed the motion of the fish body. Surprisingly, perturbations that deformed the fins extensively did not cause a reaction from either the fins or the body. These results indicate that the response of the pectoral fins to large deformations is not reflexive and that fin motions are regulated when it is necessary to correct for disturbances to the motion of the fish. The results also demonstrate a benefit of compliance in propulsors, in that external perturbations can disturb the fins without having its impact be transferred to the fish body.

High-Speed Atomic Force Microscope Technology：A Review

2021 ◽  
Vol 17 ◽  
Author(s):  
Ke Xu ◽  
Qiang An ◽  
Peng Li
Keyword(s):  
High Resolution ◽  
Atomic Force Microscope ◽  
High Speed ◽  
Control Method ◽  
Scanning Speed ◽  
Atomic Force ◽  
Wide Range ◽  
Working Principle ◽  
And Control ◽  
Dynamics Process

: The atomic force microscope (AFM) is widely used in many fields such as biology, materials, and physics due to its advantages of simple sample preparation, high-resolution topography measurement and wide range of applications. However, the low scanning speed of traditional AFM limits its dynamics process monitoring and other further application. Therefore, the improvement of AFM scanning speed has become more and more important. In this review, the working principle of AFM is first proposed. Then, we introduce the improvements of cantilever, drive mechanism, and control method of the high-speed atomic force microscope (HS-AFM). Finally, we provide the next developments of HS-AFM.

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