A Numerical and Experimental Methodology to Characterize the Gaseous Cavitation in Spool Valves with U-notches

2021 ◽  
Author(s):  
Emma Frosina ◽  
Gianluca Marinaro ◽  
Amedeo Amoresano ◽  
Adolfo Senatore
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Control Valve ◽  
Experimental Methodology ◽  
Area Of Interest ◽  
Sound Levels ◽  
Directional Control ◽  
Upstream Pressure ◽  
Spool Valves

Abstract The performance of spool valves can deteriorate and noise can occur due to cavitation. The noise sound levels caused by cavitation are influenced by many parameters, among which the most important is not-optimal geometry of components. In this paper, a 2 ways - 2 positions directional control valve was studied using experimental and numerical approaches. Tests were performed on a plexiglass body and steel spool analyzing the cavitating area that develops in U-notches. A dedicated test rig was equipped with a high-speed camera placed directly in front of the area of interest where cavitation occurs. Different working conditions were tested by varying the upstream pressure to encourage the development of cavitation. Images were acquired and post-processed, focusing the contour extraction between the liquid and gaseous phases. The images were compared with results from three-dimensional CFD numerical simulations performed using commercial software. The numerical estimation of flow characteristics corroborated the results from investigations carried out using a fast camera, including periodic cavitation structures. This study demonstrates the importance and usefulness of using a three-dimensional CFD approach during the prototyping phase to create quieter component designs.

scholarly journals Flow-Induced Vibration on the Control Valve with a Different Concave Plug Shape Using FSI Simulation

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Akram Zeid ◽  
Mohamed Shouman
Keyword(s):  
High Efficiency ◽  
Complex Structure ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Flow Simulation ◽  
Control Valve ◽  
Low Noise ◽  
Flow Induced Vibration ◽  
Nonlinear Characteristics ◽  
Flow Phenomena

Control valves have always been recognised as being among the most crucial control equipment, commonly utilised in versatile engineering applications. Hence, the need has arisen to identify the flow characteristics inside the valve, together with the incurred vibration induced as a result of the flow passing through the valve. Thanks to the tangible and fast progress made in the field of the flow simulation and numerical techniques, it has become possible to better observe the behavior of the flow passing inside a valve with view to examining its performance. Hence, the paper at hand is mainly concerned with introducing the modeling and simulation of a control valve. On the contrary, the flow system in a control valve is marked by a complex structure and nonlinear characteristics. The reasons for those qualities could be attributed to its construction as well as the fluid flow phenomena associated with it. It is especially for the sake of investigating and observing the flow characteristics, pertaining to a control valve equipped with different concave plug shapes and different openings, that the three-dimensional FSI simulation is conducted. In addition, it would be possible to make use of the obtained results relating to the three-dimensional analysis to achieve low noise and high efficiency improvement. Furthermore, all results will be validated on experimental grounds.

PIV Measurements in Diffuser of the Radial Pump

2015 ◽  
Author(s):  
Sung Yong Jung ◽  
Young Uk Min ◽  
Kyung Lok Lee
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Operating Conditions ◽  
Internal Flows ◽  
Piv Measurements ◽  
Image Velocimetry ◽  
Acquisition Device ◽  
Field Information ◽  
Radial Pump

The performance characteristics of the radial pump commonly used as a multistage (8 or 10 stage) pump have been investigated experimentally. Due to the complex three-dimensional geometries, the hydraulic performance of multistage pumps is closely related to the internal flows in diffuser and return vanes. In order to investigate the flow characteristics in these regions by Particle Image Velocimetry (PIV) technique, a transparent pump is designed. A 532 nm continuous laser and a high-speed camera are used as a light source and an image acquisition device, respectively. The velocity field information in a diffuser of the radial pump is successfully obtained by two-dimensional PIV measurements at various operating conditions.

Experimental and Numerical Study of Hydrodynamic Cavitation of Orifice Plates with Multiple Triangular Holes

2012 ◽  
Vol 256-259 ◽  
pp. 2519-2522 ◽  
Author(s):  
Zhi Yong Dong ◽  
Qi Qi Chen ◽  
Yong Gang Yang ◽  
Bin Shi
Keyword(s):  
Velocity Profile ◽  
High Speed ◽  
Numerical Study ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Orifice Plate ◽  
Hydrodynamic Cavitation ◽  
High Speed Photography ◽  
Hydraulic Characteristics ◽  
Image Velocimetry

Hydraulic characteristics of orifice plates with multiple triangular holes in hydrodynamic cavitation reactor were experimentally investigated by use of three dimensional particle image velocimetry (PIV), high speed photography, electronic multi-pressure scanivalve and pressure data acquisition system, and numerically simulated by CFD software Flow 3D in this paper. Effects of number, arrangement and ratio of holes on hydraulic characteristics of the orifice plates were considered. Effects of arrangement and ratio of holes and flow velocity ahead of plate on cavitation number and velocity profile were compared. Distribution of turbulent kinetic energy and similarity of velocity profile were analyzed. And characteristics of cavitating flow downstream of the orifice plate were photographically observed by high speed camera. Also, a comparison with flow characteristics of orifice plate with hybrid holes (circle, square and triangle) was made.

Computer Aided Design of Mixed Flow Turbines for Turbochargers

1979 ◽  
Vol 101 (3) ◽  
pp. 440-448 ◽  
Author(s):  
N. C. Baines ◽  
F. J. Wallace ◽  
A. Whitfield
Keyword(s):  
Mass Flow ◽  
Computer Aided Design ◽  
High Speed ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Design Procedure ◽  
Mixed Flow ◽  
Computer Aided ◽  
Design Calculations ◽  
Aided Design

The paper describes a comprehensive computer aided design procedure and its use to investigate mixed flow turbines for automotive turbocharger applications. The outside dimensions of rotor and casing as well as blade angles are determined from one-dimensional design and off design calculations, the detailed blade shape from quasi-three-dimensional analysis and mechanical stressing and vibration programs, and geometric data are presented as outside views and sections of the rotor by a graphics subroutine. The procedure consists of a series of separate programs rather than a single program, so that the designer’s intervention at each stage of the process can be applied. Two mixed flow rotors were designed, manufactured and tested in a specially designed high speed dynamometer. The first was intended to achieve a substantial increase in mass flow over the reference radial rotor without loss of efficiency, while the latter was intended as a direct replacement of the reference radial rotor, but should give more favorable pulse performance when operating in conjunction with an engine due to changes in the operating map viz: a) lower tip speeds for best efficiency, and b) flatter mass flow characteristics. Both effects were predicted by analysis and confirmed by tests.

3D Numerical Simulation of the Airflow in a Pneumatic Splicer

2011 ◽  
Vol 130-134 ◽  
pp. 2345-2348
Author(s):  
Xiao Xing ◽  
Guo Ming Ye
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
Air Flow ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Swirling Flows ◽  
Computational Results ◽  
Cfd Model ◽  
3D Numerical Simulation ◽  
Computational Fluid Dynamics Cfd

To investigate the effect of air flow in an pneumatic splicer on splicing performance, a computational fluid dynamics (CFD) model has been developed to simulate the air flow characteristics in an splicing chamber. Three-dimensional numerical simulation is conducted and standard K-ε turbulence model is used. Velocity distributions in the chamber are presented and analyzed. The computational results show that the velocities in the chamber are transonic. The air flows in the chamber are two swirling flows with opposite directions. This work also shows that CFD technique can provide a better understanding of the behavior of the high speed air flow in the air splicing chamber.

The Three-Dimensional Unsteady Numerical Analysis of the Internal Flow Field of the New Control Valve

2014 ◽  
Vol 980 ◽  
pp. 112-116
Author(s):  
Dong Yue Qu ◽  
Jia Lei Xu ◽  
Yang Yang Huang ◽  
Xiao Zeng Xie
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Control Valve ◽  
Internal Flow ◽  
Pulse Frequency ◽  
Computational Fluid Dynamics Cfd ◽  
Steam System ◽  
Normal Work ◽  
Vibration Noise

The medium flow of control valve is a typical complex unsteady flow, the internal flow is very unstable which leads to trim or body with vibration of different amplitude, therefore, control valve has been a failure-prone components in the turbine inlet steam system. This paper take the new valve as the research object, by computational fluid dynamics (CFD) software, the numerical simulation of the internal steam steady state flow field of valve normal work a typical opening in the process of opening is made, and obtain the internal flow field visualization distribution and flow characteristics of control valve. Extract unstable place pressure pulsation of the flow field, get the pulse frequency, and provide the basis for the design, optimization and application of low vibration noise control valve.

scholarly journals Flow Characteristics of a Highly Rotating Turbine Cavity System With Discharge Hole

1999 ◽  
Author(s):  
D. J. Maeng ◽  
J. S. Lee ◽  
R. Jakoby ◽  
S. Kim ◽  
S. Wittig
Keyword(s):  
Flow Field ◽  
High Speed ◽  
Rotational Velocity ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Rotating Disk ◽  
Disk System ◽  
High Speed Rotation ◽  
Measured Flow ◽  
Cavity System

An experimental investigation is performed to analyze the flow characteristics of a turbine cavity system containing discharge holes installed in a rotating disk. The turbine cavity system is composed of a rotating disk and two stationary disks on both sides of the rotating disk. The air flow is induced into the upstream cavity, and then discharged into the downstream cavity through 8 discharge holes in the rotating disk. The flow field in each cavity at high-speed rotation of the rotor was measured by a three-dimensional LDV system. The measured flow field is analyzed to understand the flow structures, and further provide information for studying the heat transfer behaviors of the turbine disk system. The overall flow field in the upstream cavity shows a negligible axial velocity with a relatively small rotational velocity, less than 10% of the rotor speed. The downstream cavity flow has a high rotational velocity close to the rotational speed of the discharged jets, due to the direct circumferential momentum transfer from the discharged jets. The interaction between the discharged jet and the downstream stator disk induces an asymmetric development of the spreading wall jet, which results in a relative circumferential motion to the revolving discharged jet. The whole flow field in the downstream cavity is divided into several flow regions according to their features.

scholarly journals Development and Testing of Hydraulic ‘Bharath Valve’ to Control Multiple Actuators

2019 ◽  
Vol 9 (2) ◽  
pp. 2727-2737
Keyword(s):  
Hydraulic System ◽  
Outer Cylinder ◽  
Performance Testing ◽  
Control Valve ◽  
Directional Control ◽  
Direction Control ◽  
Cheap Alternative ◽  
And Performance ◽  
Multiple Actuators ◽  
Spool Valves

The Research is entitled “Design, Fabrication and Performance Testing of Directional Control Valve for Control of Multiple Actuators”. An indexing unit is a direction control valve used in Hydraulic system. This device shall be named ‘Bharath Valve’ (US10180190), as is the name of its Inventor. This valve can control more than one number of actuators. This valve consists of a hollow outer cylinder and inner cylinder. The inner cylinder fits in the hollow portion of outer cylinder; this inner cylinder is operated manually. The rotation of the inner cylinder inside the outer cylinder changes the direction of flow of liquid through the valve this control the movements of actuator. This Indexing valve can become a highly advantageous replacement of the conventional Spool valves that are used for controlling the actuator. In the present scenario one spool valve can control only one actuator thus the number spool valves used in a hydraulic system is equal to the number of actuators. However ‘Bharath’ valve can control more than one number of actuators, this in turn makes the number of system components less and also reduces the overall cost of hydraulic system. Even the controlling of movement of actuators can be easy. A computer interface if given can make this valve versatile and a very cheap alternative to the existing valves, taking number of components, construction, friction and efficiency into account. This research proves that ‘Bharath’ valve has more advantages than that of existing ones and some of the advantages are listed below,  One valve can control more than one actuators thus reduces the number of valves.  Construction of this indexing valve is simpler and parts involved in friction is less.  Reduction in the cost of manufacturing is highly significant.  This valve makes it possible to actuate the desired cylinder keeping the other at rest.  The modification in operating actuators of system can be easily changed by operating ON/OFF flow valve connected to the inlets of Indexing valve.

Investigation of Swirl Ratio Impact on In-Cylinder Flow in an SIDI Optical Engine

2016 ◽  
Vol 138 (8) ◽  
Author(s):  
Hanyang Zhuang ◽  
David L. S. Hung ◽  
Jie Yang ◽  
Shaoxiong Tian
Keyword(s):  
High Speed ◽  
Soot Formation ◽  
Flow Characteristics ◽  
Engine Performance ◽  
Control Valve ◽  
Swirl Flow ◽  
Exhaust Emission ◽  
Swirl Ratio ◽  
Optical Engine ◽  
Cylinder Flow

Advanced powertrain technologies have improved engine performance with higher power output, lower exhaust emission, and better controllability. Chief among them is the development of spark-ignition direct-injection (SIDI) engines in which the in-cylinder processes control the air flow motion, fuel–air mixture formation, combustion, and soot formation. Specifically, intake air with strong swirl motion is usually introduced to form a directional in-cylinder flowfield. This approach improves the mixing process of air and fuel as well as the propagation of flame. In this study, the effect of intake air swirl on in-cylinder flow characteristics was experimentally investigated. High-speed particle image velocimetry (PIV) was conducted in an optical SIDI engine to record the flowfield on a swirl plane. The intake air swirl motion was achieved by adjusting the opening of a swirl ratio (SR) control valve which was installed in one of the two intake ports in the optical engine. Ten opening angles of the SR control valve were adjusted to produce an intake SR from 0.55 to 5.68. The flow structures at the same crank angle degree (CAD), but under different SR, were compared and analyzed using proper orthogonal decomposition (POD). The flow dominant structures and variation structures were interpreted by different POD modes. The first POD mode captured the most dominant flowfield structure characteristics; the corresponding mode coefficients showed good linearity with the measured SR at the compression stroke when the flow was swirling and steady. During the intake stroke, strong intake air motion took place, and the structures and coefficients of the first modes varied along different SR. These modes captured the flow properties affected by the intake swirl motion. Meanwhile, the second and higher modes captured the variation feature of the flow at various CADs. In summary, this paper demonstrated a promising approach of using POD to interpret the effectiveness of swirl control valve on in-cylinder swirl flow characteristics, providing better understanding for engine intake system design and optimization.

A 4/3-Way Flat Slide Valve With a Metallic Main Stage

2020 ◽  
Author(s):  
Stefan Aengenheister ◽  
Chao Liu ◽  
Felix Figge ◽  
Christoph Broeckmann ◽  
Katharina Schmitz
Keyword(s):  
Service Life ◽  
Test Bench ◽  
Control Valve ◽  
Slide Valve ◽  
Main Stage ◽  
Gap Formation ◽  
Directional Control ◽  
Technical Ceramics ◽  
Pressure Compensation ◽  
Spool Valves

Abstract Most proportional directional control valves currently in practical use are piston spool valves. A disadvantage of this type of design is the occurring leakage between spool and sleeve or housing. A second disadvantage is that the service life is limited by wear on the control edges. The ceramic flat slide valve is a promising concept, which allows to reduce the mentioned leakage and to increase service life. In contrast to piston spool valves, the main stage of the flat slide valve consists of three plates. Two control plates and a movable slide plate, which is located in between. An external force is applied to the plates by the so-called pressure compensation, which presses the plates together and thus counteracts a gap expansion and thereby an effective reduction of occurring leakage is accomplished. The plate-by-plate design of the main stage allows the use of technical ceramics, which are more resistance to abrasive wear and can thereby extend the service life of valves. A challenge in the realization of the flat slide valve is the design of the pressure compensation. If the force applied by the pressure compensation is not sufficient to prevent a gap formation between the plates, an increased leakage will occur, which results in a reduction of efficiency. In case the applied force is too high due to the pressure compensation, high frictional forces between the plates occur and an adjustment of the slide plate position through an actuator is no longer possible. Therefore, the design of the pressure compensation is essential for the success of the concept. This contribution presents the results of testing a main stage, which consists out of two metallic control plates and a slide plate made of special brass. The main stage is designed in such a way that a 4/3-way directional control valve with a proportional characteristic can be realized, as it is also achieved by valves currently available on the market. Therefore, in addition to the pressure forces, further influences on the resulting force of the pressure compensation were determined and their influence was estimated based on test bench results. With a program written in MATLAB, the forces prevailing in the valve can be calculated time-efficiently for different geometries and are validated with test bench trials.

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