High-speed Valve Research Articles

Numerical Study on the Internal Flow Field Characteristics of a Novel High-Speed Switching Control Valve

Numerical Study on the Internal Flow Field Characteristics of a Novel High-Speed Switching Control Valve

Design and performance analysis of high-speed on/off valve based on energy-coupled actuator

The development digital hydraulics demands higher performance on high-speed on/off valves. In order to fully exploit the energy saving advantages of digital hydraulics, advanced high-speed valves are expected to possess a fast response and a large nominal flow rate simultaneously. Energy-coupled-actuator (ECA) utilizes the shear working mode of magnetic rheological fluid to achieve reciprocating motion of the valve spool through the coupling/decoupling of a pair of disks and a translational piece and its driving force is not affected by the valve spool’s position. The reported advantages of ECA meets the design requirements of actuators for high-speed on/off valve. This study gives the detailed design proposal of high-speed valve based on ECA (ECAV). The work also established a multi-physics coupled model for ECAV, calculated the key parameters of the valve driving system, and predicted the switching performance of ECAV. Finally, a prototype of ECAV with updated sealing solution between the actuator and valve block was fabricated and experimental tested. The results indicate that for current ECAV prototype successfully established 40 l min−1@5 bar (1.5 mm stroke) using response time less than 7 ms. Moreover, the prototype only consumed 14 ms to reach a long stroke of 5 mm with a significantly increased ratio of stroke over response time.

Performance optimization and testing of a novel energy coupled actuated high-speed valve based on peak-and-hold driving strategy

High-speed on/off valve acts as critical enabling component of digital hydraulics, which has been challenging the traditional hydraulic system by providing efficient and effective hydraulic control solutions. The high-speed on/off valve that ideally fits the digital hydraulic system is expected to achieve fast response and long stroke with affordable energy consumption. This not only requires developing advanced actuation mechanism but also demands extensive study on the driving strategy. This study focuses on investigating the Peak-and-hold driving strategy applied to a novel high speed on/off valve-energy coupling actuated valve (ECAV), in order to achieve target performance with optimized energy consumptions. This work has developed an electro-mechanical coupled physics model based on commercial finite element solver COMSOL. This model helps to investigate the performance of ECAV under different peak-and-hold driving parameters and thereby recommend the optimal peak-and-hold driving strategy. Then, the experimental testing on the prototype ECAV has been conducted to validate the simulated performances. The measurement results showed that the prototype ECA using the optimal peak & hold solution demonstrated significant advantage in energy saving targeting at response of 10 ms for 1.5 mm stroke, especially compared to a typical step input signal.

Magnetron sputtering thruster operated with a compact gas feeding system using double pulsed valves

A continuous injection of gaseous water propellant into a magnetron-type sputtering propulsion device is performed in a pseudo manner by using a combination of two high-speed solenoid-type pulsed valves and a low-pressure gas reservoir . The gas injection system provides a temporally averaged gas flow rate of about 5–10 sccm with adjustment of the repetition frequencies of the pulsed valves, while the previously used single valve system attached to a liquid water tank has caused excessive gas injection. A discharge is sustained by a high voltage dc power supply; the discharge current has pulsation synchronized with the pulsed valve repetition. A temporally averaged force induced by the magnetron sputtering thruster and exerted on a pendulum plate downstream of the thruster is measured; the results are in good agreement with the previously reported force measurement under precisely controlled gas flow rate using a commercial mass flow controller. Therefore, the precise control of the gaseous water propellant with the compact gas feeding system is achieved, while maintaining a similar thruster performance to that with the mass flow controller.

AVD-YOLOv5: a new lightweight network architecture for high-speed aortic valve detection from a new and large echocardiography dataset.

Heart disease detection is currently gaining widespread attention as a means to enhance the accuracy of cardiologists' diagnoses from cardiac images and reduce diagnosis time. Although high-resolution computed tomography (CT) images are typically favored for heart disease detection, the drawbacks of cost and radiation exposure to patients necessitate alternative approaches. In this context, utilizing ultrasound images becomes pivotal to mitigate radiation risks and maintain cost-effectiveness. In this paper, we propose a novel lightweight model, AVD-YOLOv5, designed for automated aortic valve detection on echocardiography images. This model incorporates several enhancements to the YOLOv5 architecture. Notably, the depth-wise separable convolution significantly contributes to the model's lightweight design by reducing the number of parameters while maintaining precision. We have also created a new and larger dataset comprising 260 echocardiography images specifically for aortic valve detection. Experimental results indicate that the precision value of the modified ADV-YOLOv5 model stands at 94.3%, with a recall value of 86.8%. The model also demonstrates a notable 67% reduction in inference time compared to the original YOLOv5 model. Although there is a marginal reduction in precision by 0.94%, the model's efficiency is significantly increased. The proposed system can be used by cardiologists for more efficient and reliable diagnosis.

Improvement of dynamic response and energy conversion ratio of a global type solenoid for high-speed valve by using an innovative magnet ring

The transient behavior and energy transmission of a global type solenoid for high-speed valve (HSV) depend upon the magnetic force acting on the sphere. Rapid responses are challenging to achieve because of the limited power supply energy, which makes it hard to optimize the magnetic force through its own structural characteristics for HSV. Aiming to obtain higher magnetic force without increasing the input electric power, an innovative magnet radial ring is presented and a relative evaluation of magnetic forces exerted on a global type solenoid for HSVs is conducted. A hollow-plunger-type magnet radial ring is engineered as a novel magnet ring form. The magnetic forces and transient action time of the conventional HSV and innovative HSV are evaluated by means of finite element method (FEM) analysis and demonstrated by verification of the experimental data. The assessment of the magnetic forces involves every solenoid with a diverse magnet ring shape with the variation of height and thickness. The suggested novel magnet ring successfully increases the magnetic force applied to the sphere by changing the internal magnetic connection structure and increasing the mechanical energy conversion ratio, according to a methodical comparison of the two HSVs' transient performances. Meanwhile the innovative magnet ring can reduce the strength of iron loss occurred in the magnetic field of HSV to realize the reduction of useless power loss. At the magnetization position at the attraction, the magnetic force is 17.35 N, while the magnetic ring increases the magnetic force to 28.84 N. Also, the maximum rising speed of the magnetic force is improved from 14945 N/ms to 38904 N/ms, and the transient action time is reduced from 3.74 ms to 1.30 ms. For the mechanical energy and iron loss energy in energy conversion occurred in solenoid, the mechanical energy ratio increases from 16.2 % (conventional valve) to 27.8 % (innovative valve) with height 26 mm and thickness 3.5 mm, while the iron loss energy ratio decreases from 40.7 % (conventional valve) to 31.8 % (innovative valve) synchronously.

Temporally resolved measurement of a force induced by a pulsed water-fuelled magnetron sputtering source

A high-speed solenoid-type pulsed valve is applied to a water-fuelled magnetron sputtering thruster, which can lead a compact and neutralizer-free electric propulsion device by generating a thrust due to the ejection of the sputtered target material, in order to minimize the size of the gas feeding system. The pulsed valve is opened for approximately 5 msec and the gaseous water is introduced into the source via a gas line connected to the source. A dc high voltage is firstly applied between the cathode and the anode; then the discharge is sustained for the period in which a gas pressure enough for the discharge is maintained and a change in the discharge mode is observed during the discharge pulse. To investigate the impact of the mode change on the thrust generation, a temporally resolved measurement of the force is equivalently performed by installing a pulsed voltage power supply and by changing the pulse width of the discharge voltage. The results show the temporal reduction of the thrust-to-power ratio during a pulsed discharge due to the nonlinear correlation between ion energy and sputtering yield. It is suggested that the use of a pulsed valve would be useful for downsizing of the electric propulsion system, while an optimization to properly control the gas flow rate is needed for further development.

Cyclic Impact Test with the Hopkinson Bar: Application to Granite

A laboratory scale cyclic impact loading test was developed by modifying a Hopkinson Bar test setup. The modifications involve placing a special shank piece between the striker and the rest of the setup. The shank transmits the impact loading and enables the use of compressed air for rapid reloading of the striker. The short shank is in direct contact with the specimen, i.e., there is no long input bar. With this configuration residual wave motion and reloading of the specimen is avoided. Behind the striker an output bar and momentum trap bar are placed for specimen loading measurement and removal of the wave motion in the system, respectively. The trap bar is stopped by a pneumatic actuator, which also resets the bars and the specimen before the next impact loading. The compressed air flow driving the striker is controlled by high-speed electropneumatic valves connected to a control unit and operated in simple open-loop control. Numerical simulations of both the striker motion by compressed air and dynamic loading wave propagation during impact were used in the design phase as well as setting up the test parameters. The test setup is able to produce stable cyclic impact loading at a frequency of up to 10 impacts per second with striker velocity up to 9 m/s. The feasibility of the test method is demonstrated by providing data from cyclic Brazilian disc experiments on Balmoral Red granite at both impact and quasi-static cyclic loading.

Investigation of mass transfer in valve-controlled gas–liquid segmented flow

Segment flow is widely employed in gas–liquid microreactor systems owing to its enhanced mass transfer through the biphasic interface. Previous studies evaluating an increased fluid flow rate (F) have reported an increased volumetric mass transfer coefficient (kLa) and reduced segment length (L). In a conventional microsystem, manipulating L without varying the residence time of the fluids is challenging. Hence, the relationship between kLa and L has not been systemically investigated under the same F. In this study, L control without changing F is implemented by introducing a high-speed valve into a gas–liquid microchannel system, and the influence of L on kLa is investigated by altering the valve frequency (f). The results indicate that kLa in the segmented flow is negatively correlated with L at constant F and reaches 0.149 s–1 (332.6 times larger than that in the bubble), whereas the specific area (a) of the segmented flow increases with increasing f before the liquid phase is saturated. Moreover, a and instinct kLa can be predicted using f, F, and the microchannel diameter. The outcomes of this research will improve the understanding of the mass transfer phenomenon in gas–liquid segmented flows and provide support for the design of microreactor systems.

A fully automated Lab-on-a-Disc platform integrated a high-speed triggered siphon valve for PBMCs extraction

Human Peripheral Blood Mononuclear Cells (PBMCs) are isolated from peripheral blood and identified as any blood cell with a round nucleus that exhibits immune responses and undergoes immunophenotypic changes upon exposure to various pathophysiological stimuli. Obtaining high-recovery and clinical-grade PBMCs without decreasing cell viability and causing stress is crucial for disease diagnosis and successful immunotherapy. However, traditional manual PBMCs extraction methods rely on manual intervention with less recovery rate and reliability. In this study, we introduced a novel and efficient strategy for the fully automated extraction of PBMCs based on a Lab-on-a-Disk (LoaD) platform. The centrifugal chip used percoll as density gradient media (DGM) for separation and extraction on account of the density difference of cells in whole blood, without labeling and any additional extra cellular filtration or cell lysis steps. Above all, we proposed a high-speed triggered siphon valve, which was closed under the speed of cell sedimentation and subsequently opened by increasing speed to complete the extraction of PBMCs. It can avoid the problem that previous siphon valves rely on unstable hydrophilic surface treatment and prime under low/zero speed conditions. With valves and the clock channel integrated on the chip, users can achieve fully automated collection of PBMCs. Compared with the clinical laboratory results, the recovery rate of extracted PBMCs was 80 %. The experimental results prove that the high-speed triggered siphon valve improves the extraction efficiency of PBMCs. The robust chips, which are not only simple to manufacture and assemble but also stable and reliable to use, have great potential in biomedical and clinical applications.

High throughput continuous synthesis of size-controlled nanoFe3O4 in segmented flow

NanoFe3O4, a magnetic nanoparticle, boasts wide-ranging applications, from magnetic separation to imaging, labeling, and remote control of targeted drug delivery. However, the conventional nanoFe3O4 synthesis in a batch reactor is time- and energy-intensive. In the currently developed continuous synthesis strategies, the complexity of the rotating packed bed reactor and the low capacity of the microfluidic chip impedes the application of these devices for the fabrication of nanoFe3O4. Hence, for the continuous synthesis of nanoFe3O4, a simple and convenient device with high throughput is urgently required. Microfluidic technology presents promising approaches that can enhance mass and heat transfer in segmented flow, surpassing the limitations of conventional methods. In this study, continuous synthesis of nanoFe3O4 was achieved in segmented flow within a microchannel, utilizing the coprecipitation method. The influence of iron concentration, reaction temperature, and the Fe2+:Fe3+ ratio on the synthesis of nanoFe3O4 were investigated thoroughly. Based on the results, analyzed through X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), this segmented flow synthesis strategy was proved to be capable of fabricating nanoFe3O4 of approximately 6 nm. Moreover, by increasing the high-speed valve frequency, thus reducing the segment length, the size distribution range of nanoparticles was reduced and uniform nanoparticles were synthesized. The continuous synthesis method developed through our research offers significant advantages over other existing technologies in terms of productivity and manufacturing cost. Therefore, it offers a promising pathway for the industrial-scale continuous synthesis of nanoFe3O4.

Dynamic Design of a Novel High-Speed Piezoelectric Flow Control Valve Based on Compliant Mechanism

Piezoelectric actuators are particularly interesting in high-speed precision flow control valves due to their fast dynamic response and simple structure. However, concurrently improving the dynamic bandwidth and flow rate has been a challenging issue. In this article, a novel two-stage flow control valve driven by amplified piezoelectric actuator is proposed, fabricated, and tested with the step response time of 5 ms, flow rate of 70 L/min, and the dynamic bandwidth of 155 Hz at the supply pressure of 30 bar. An improved rhombus-type compliant mechanism with double output ports is proposed to amplify the microstroke of piezostacks with a relatively high resonance frequency. Two pilot sliding spools are differentially actuated moving the main spool back and forth, modulating the flow rate and direction. The coupling dynamics of the piezohydraulic valve is also formulated on the Laplace domain with the concept of two-port dynamic stiffness model and control theory. The influence of key structural parameters on the flow characteristics is analytically calculated, and the optimal static and dynamic performances are obtained. The theoretical prediction is in reasonable agreement with the experimental results in the closed-loop control, proving that the operational concept is viable.

Controlling gas–liquid segment length in microchannels using a high-speed valve

Segmented flow, one of the most important flow patterns in microchannels, has been widely employed in gas–liquid microreactor systems because it enhances mass transfer through the biphasic interface. The segment length is determined by the channel parameters (e.g., size, material type), fluid flow rate, and fluid properties. Thus, it is difficult to manipulate the gas–liquid segment length without affecting the residence time of the fluid. In this work we successfully achieved regularly segment length control by introducing a high-speed valve into a gas–liquid microchannel system while varying the frequency of the valve installed in the gas-phase tube to allow gas and liquid segment lengths to be controlled within a large range. In contrast, the segment lengths were almost constant under the same conditions without the high-speed valve. Furthermore, a gas/liquid flow rate ratio in the range of 0.7–1.2 was deemed necessary for steady segmented flow. Finally, a correlation was proposed to predict the segment length using parameters such as valve frequency and fluid flow rate, and it matched the experimental data well. This segment length control strategy will improve the performance of gas–liquid reactions in microreactors and advance the design of microreactor systems.

Design and performance research on the actuator of high-speed valve based on shear working mode of magnetorheological fluid

The high-speed valve with advanced performance, which is expected to possess characteristics of large nominal flow and fast response at the same time, plays an important role in enabling efficient digital hydraulics. In order to solve the tradeoff between a large rated flow and less response time, this paper proposed a novel design of high-speed valve actuator called energy coupler actuator (ECA) based on the shear working mode of magnetorheological fluid. The ECA allows a rotary energy source couple/decouple the translational valve spool for fast and long stroke on/off switching. This work developed a multi-physics model of ECA to study its performance and simulation work based on response surface method has been conducted to optimize the ECA design parameters. An ECA prototype with the optimal design solution has been manufactured and experimentally tested. The testing results shows that driven by the power level similar to off-the-shelf solenoid valves, this ECA prototype only took 5 ms to achieve 1.5 mm stroke, which provide a flow area equivalent to a nominal flow of 100 l min−1@5 bar. This prototype also demonstrated the ECA’s design feature of long stroke with quick response by achieving 7 mm stroke in just 16 ms.

Double duty ratio PWM control method for a novel HSV actuator with low power consumption

This paper presents a novel high speed valve (HSV) actuator with low power consumption. The structure design of tapered armature and control method of double duty ratio pulse width modulation (PWM) are proposed in the HSV actuator to improve steady and transient characteristics. The electric-magneto-mechanical model of the HSV actuator is established and investigated by theoretical analysis. Parameters improvement of the HSV actuator is analyzed by the model, and optimized results for a prototype actuator have been obtained. The experimental and simulation curves agree well with the changing trend, and show that the opening time of the HSV actuator is 7.3 ms, the closing time is 20 ms, and power consumption in maintenance stage is 1.35 W, within the stroke of 2.5 mm. Compared with normal driving method, the proposed structure and method have the advantages of opening time reduced by 37%, closing time reduced by 29%, and steady-state power consumption reduced by 93.5%. The proposed structure and method in the HSV actuator are available to meet the driving requirements of both steady and transient performance in fluid control systems better, especially in power shortage or power supply inconvenient engineering.

Multi-mode soft haptic thimble for haptic augmented reality based application of texture overlaying

This paper presents a novel thimble-shape haptic display for multi-mode tactile feedback at fingertips. The device has two special characteristics. Multi-mode feedback, i.e., static pressure, high-frequency vibration, and impact force, can be generated via a single actuator mechanism of a pneumatic chamber controlled by high-speed valves. Additionally, the actuator’s softness makes this device a “feel-through” tactile display where the user simultaneously feels responses from a real object and synthetic feedback. This makes the device a fit for haptic augmented reality-based display where real and virtual touch feedback is merged into single feedback that haptically “augments” the real world.A layered combination of flexible and non-flexible silicone membrane surrounds the air- cavity for desired efficiency, and systematic valve control algorithms are developed for rich haptic effects. The experiments confirmed that the system generated a static force up to 7 N, acceleration magnitude up to 1.4 G, and frequency up to 250 Hz. The device exhibits two realistic tactile signals, i.e., virtual textures and button clicks, based on real signals and a physical surface that are augmented with two haptic signals.The user studies revealed that the participants found the virtually overlaid textures and buttons to be perceptually similar to their real counterparts.

Simulation Research on Thermal Characteristics and Experimental Study on Electronic Control Board of the Miniature High-Speed Digital Valve

The miniature high-speed digital valve is essentially a kind of miniature system that contains many nonlinear factors and involves multifield coupling among electromagnetic, mechanical, and liquid ones. In this study, the dimension of an electromagnetic structure is normalized into a unified variable, and the numerical analysis method is used to optimize the values of each parameter size on the premise of satisfying the requirements. The electronic control board is the control signal input equipment of the valve. The input changes of voltage and current directly affect the thermal characteristics of the valve. The electronic control board is the power source of the digital valves, and their high speed partially depends on the characteristics of the electronic control board. In this study, a control board for miniature digital valves was developed, which realizes the rapid rise and fall of current and meets the design requirements. A new electronic control board is manufactured, and a control platform for the electronic control board is built. Experiments demonstrate that there is no delay in the current rise and fall, showing that the valve achieves its dynamic response target. Using the finite element analysis software Workbench to simulate it numerically, the temperature field distribution in the original structure is not uniform, which affects the magnetic properties of the electromagnetic field. To address this disadvantage, this study proposes to insulate the heat source with thermal insulation material, which will not affect the temperature distribution of the entire electromagnetic components. The simulations show that the proposed method is effective and reliable.

Switching characteristics of a high-speed rotary valve for switched inertance hydraulic converters

The switched inertance hydraulic converter is a sub-domain of digital hydraulics which relies on digital switching to adjust pressure or flow instead of the dissipation of power by throttling, providing an energy-efficient alternative to conventional proportional or servo valve-controlled systems. The high-speed switching valve is a key component to realise the digital switching and its switching characteristics has significant effects on the performance of switched inertance hydraulic converters. In this article, the switching characteristics of a high-speed rotary valve are investigated. The switching orifice area of the valve is calculated based on the movement of the valve components with a consideration of the design of the valve body and leakage. This is validated using the computational fluid dynamics model and in experiments. The valve is theoretically modelled considering the switching orifice, leakage, transition throttling and compressibility effect, and the results are validated by computational fluid dynamics and experimental tests. The valve is able to deliver a flow rate of 40 L/min at a pressure drop of 10 bar and switch at the maximum frequency of 317 Hz, with a switching transition time of about 1 ms, which shows promising performance for the use in digital hydraulics. The theoretical and computational fluid dynamics models can assist the design and optimisation of digital high-speed rotary valves, which can be very useful for understanding, analysing and optimising the characteristics and performance of switched inertance hydraulic converters in digital hydraulics.

Design and integrated stroke sensing of a high-response piezoelectric direct-drive valve enhanced by push-pull compliant mechanisms.

Enhancing the dynamic bandwidth of flow control valves based on piezoelectric actuators has attracted much attention in the field of precision fluid control. This paper reports a high-speed piezoelectric direct-drive flow control valve with an enhanced flow rate by introducing a new push-pull complementary compliant mechanism. An improved semi-rhombus compliant amplifying mechanism is designed to amplify the microstroke of piezo-stacks with an enhanced resonance frequency. To facilitate the design, the dynamic stiffness model of the compliant amplifying mechanism is derived and the structural parameters are optimized using the Pareto multi-objective optimization strategy. In addition, a polyvinylidene fluoride (PVDF) based high-response displacement sensor with an improved differential charge amplifier circuit is developed and integrated into the valve to measure the spool displacement in real time. A proof-of-concept prototype is fabricated, and the flow characteristics are experimentally tested in a closed-loop control with the PVDF sensor. The flow rate and dynamic bandwidth of the presented piezo-valve are evidently enhanced, reaching the dynamic bandwidth in excess of 920 Hz (-3 dB) and the flow rate of ±6 l/min (corresponding stroke is 0.2 mm) under the supply pressure of 70 bars.

Deep Learning Prediction for Rotational Speed of Turbine in Oscillating Water Column-Type Wave Energy Converter

This study uses deep learning algorithms to predict the rotational speed of the turbine generator in an oscillating water column-type wave energy converter (OWC-WEC). The effective control and operation of OWC-WECs remain a challenge due to the variation in the input wave energy and the significantly high peak-to-average power ratio. Therefore, the rated power control of OWC-WECs is essential for increasing the operating time and power output. The existing rated power control method is based on the instantaneous rotational speed of the turbine generator. However, due to physical limitations, such as the valve operating time, a more refined rated power control method is required. Therefore, we propose a method that applies a deep learning algorithm. Our method predicts the instantaneous rotational speed of the turbine generator and the rated power control is performed based on the prediction. This enables precise control through the operation of the high-speed safety valve before the energy input exceeds the rated value. The prediction performances for various algorithms, such as a multi-layer perceptron (MLP), recurrent neural network (RNN), long short-term memory (LSTM), and convolutional neural network (CNN), are compared. In addition, the prediction performance of each algorithm as a function of the input datasets is investigated using various error evaluation methods. For the training datasets, the operation data from an OWC-WEC west of Jeju in South Korea is used. The analysis demonstrates that LSTM exhibits the most accurate prediction of the instantaneous rotational speed of a turbine generator and CNN has visible advantages when the data correlation is low.