scholarly journals Design and Flow Analysis of an Adjustable Check Valve by Means of CFD Method

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2237
Author(s):  
Grzegorz Filo ◽  
Edward Lisowski ◽  
Janusz Rajda

The article presents results of research on an adjustable check valve. In particular, the article deals with improvement of flow characteristics and reduction in pressure losses of an existing valve design. The subject of the research was the valve body in the form of a steel block intended for mounting a typical cartridge valve insert. Two variants of the valve body were analysed: a standard one, which is currently in production, and the proposed new solution, in which the geometry was modified based on the results of CFD simulations. The main research task was to properly shape and arrange holes and flow channels inside the body, between the cartridge valve and the connecting plate. Using CFD analyses, a solution for minimising the flow resistance was sought and then the method of modifying flow channels geometry was developed. The CFD simulation results showed a significant reduction in pressure loss, up to 40%. The obtained simulation results were verified on a test bench using a prototype of the proposed valve block. A high degree of consistency in the results of CFD simulations and laboratory experiments was achieved. The relative difference between simulation and experimental results in the entire considered range of the flow rate did not exceed 6.0%.

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
Semi Kim ◽  
Junyoung Park ◽  
Bumseok Choi ◽  
Jehyun Baek

The objectives of the present study were to investigate the flow structure and assess the accuracy of loss correlations in the symmetric volute of a turbo-blower using 3D steady flow analysis methods. To accurately model the flow field in the volute, an impeller with a single blade, a diffuser with 13 vanes, and a volute were used as the calculation domains for the computational fluid dynamics (CFD) simulations. Numerical results were validated by comparison with experimental results for the performance of a turbo-blower operated under three operating conditions: high (0.38 kg/s), normal (0.3 kg/s), and low (0.23 kg/s) mass flow rates. The accuracy of the loss correlation sets reported in four previous studies was compared with the CFD simulation predictions. These comparisons showed that the correlation sets did not accurately represent the total pressure loss in the symmetric volute of a turbo-blower, and a modified correlation set that included adjustments for the loss coefficients was proposed. Detailed investigations of the simulated flow fields were compared to understand the flow characteristics in the volute under the designed operating conditions.


2010 ◽  
Vol 139-141 ◽  
pp. 913-916 ◽  
Author(s):  
Guo Liang Hu ◽  
Wei Gang Chen ◽  
Zhi Gang Gao

In order to investigate the influence rules between the jet nozzle of fire water monitor and the jet performances, two typical jet nozzle, the spray jet and direct jet nozzle was designed to analysis the jet flow characteristics. Flow simulation of the jet nozzle was completed using fluent kits. The outlet velocity of the spray jet nozzle and direct jet nozzle were investigated in detail, and the influence rules of the nozzle structure on the outlet velocity was also discussed. The simulation results show that the steady velocity of the jet nozzle is about 34m/s that coinciding the contour magnitude, and the better extended length of the direct jet nozzle is about 50mm length that can improve the jet performances. The results can verify the reasonableness of the designed nozzle, it also can optimize the nozzle structure and increase the jet performance of the fire water monitor.


2018 ◽  
Vol 180 ◽  
pp. 02044 ◽  
Author(s):  
Roman Klas ◽  
Vladimír Habán ◽  
Pavel Rudolf

Several modifications were developed when designing the nozzle valve. This study offers an assessment of the properties of new modifications of the nozzle valve design. The main operating characteristics, such as loss and flow coefficients, were determined using a CFD methods. Besides mentioned coefficients, the forces acting on the valve disc are also decisive for the behavior of the valve, both in its steady and unsteady operation. It is important to examine the possible simplification and matching of CFD simulation results from 2D and 3D geometries in terms of subsequent dynamic analysis of the valve. This will be taken into consideration by comparing the above-mentioned operating characteristics, by analyzing the forces acting on the valve disc and comparing the velocity and pressure fields.


Telecom ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 285-301
Author(s):  
Mariella Särestöniemi ◽  
Marko Sonkki ◽  
Sami Myllymäki ◽  
Carlos Pomalaza-Raez

This paper describes the development and evaluation of an on-body flexible antenna designed for an in-body application, as well as on-body communications at ISM and UWB frequency bands. The evaluation is performed via electromagnetic simulations using the Dassault Simulia CST Studio Suite. A planar tissue layer model, as well as a human voxel model from the human abdominal area, are used to study the antenna characteristics next to human tissues. Power flow analysis is presented to understand the power flow on the body surface as well as within the tissues. Simulation results show that this wearable flexible antenna is suitable for in-body communications in the intestinal area, e.g., for capsule endoscopy, in the industrial, scientific, and medical (ISM) band and at lower ultra-wideband (UWB). At higher frequencies, the antenna is suitable for on-body communications as well as in-body communications with lower propagation depth requirements. Additionally, an antenna prototype has been prepared and the antenna performance is verified with several on-body measurements. The measurement results show a good match with the simulation results. The novelty of the proposed antenna is a compact size and the flexible substrate material, which makes it feasible and practical for several different medical diagnosis and monitoring applications.


Author(s):  
Hui Ding ◽  
Benjamin Greenfield

Abstract This paper describes how CFD simulations were used to help evaluating a centrifugal pump performance. The simulated pump was designed totally from scratch. Many aspects of pump performance characteristics were predicted based on the geometry generated using a pump design software. Especially the effects of the free spin of the 3rd rotor in a 3 stage pump assembly on overall performance were evaluated. Pump models, simulation techniques, and simulation approaches will be presented in detail. Simulation results will be discussed and compared with available test data.


Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2186
Author(s):  
Yong-Jie Zeng ◽  
Sheng-Jye Hwang ◽  
Yu-Da Liu ◽  
Chien-Sheng Huang

A motor core is formed by stacking iron sheets on top of each other. Traditionally, there are two stacking methods, riveting and welding, but these two methods will increase iron loss and reduce usage efficiency. The use of resin is the current developmental trend in the technology used to join iron sheets, which has advantages including lowering iron loss, smoothing magnetic circuits, and generating higher rigidity. The flow behavior of resin in gluing technology is very important because it affects the dipping of iron sheets and the stacking of iron sheets with resin. In this study, a set of analytical processes is proposed to predict the flow behavior of resin through the use of computer-aided engineering (CAE) tools. The research results are compared with the experimental results to verify the accuracy of the CAE tools in predicting resin flow. CAE tools can be used to predict results, modify modules for possible defects, and reduce the time and costs associated with experiments. The obtained simulation results showed that the filling trend was the same as that for the experimental results, where the error between the simulation results for the final dipping process and the target value was 0.6%. In addition, the position of air traps is also simulated in the dipping process.


2015 ◽  
Author(s):  
Hans Jørgen Mørch ◽  
Thomas Larsen ◽  
Erik Mostert ◽  
Karl Marius Norschau ◽  
Gunnar Semb

Through use of state of the art tools for flow analysis the aims to establish a methodology to determine the performance of a high speed planing craft both in calm water and in waves. Verification against full scale measurements is conducted. The ability to maintain speed in waves is of great interest -both with respect to added resistance and with respect to safe operation and loads on the crew from accelerations. Full scale measurements and CFD (Computational Fluid Dynamics) were conducted on a Norsafe Magnum 850fast patrol boat. The measurements have been conducted during a boat challenge along the Iberian coast. The challenge was run in advance of the HSBO (High Speed Boat Forum) which was held in Lisbon, Portugal, May2015.CFD simulations at similar conditions to the measurements are used for validation. It is further shown how CFD can be used to expand operational envelopes beyond the point where full scale measurements are applicable. This is especially relevant for the acceleration loads on the crew which is often the limiting factor of small HSC (High Speed Crafts). Pressure loads are extracted from the CFD and are evaluated against the current standards for life boats. Various criteria are discussed and the most relevant are analyzed for the measurement results and the CFD simulation. An operational envelope where the different criteria are combined is suggested.


1997 ◽  
Vol 119 (2) ◽  
pp. 192-198 ◽  
Author(s):  
K. K. Botros ◽  
B. J. Jones ◽  
O. Roorda

In the design of natural gas compressor stations, a check valve is a critical element which is commonly placed on the discharge side of the compressor to prevent reverse flow that can cause serious damage to the compressor itself and other components such as seals and bearings. One of the selection criteria of the check valve for this particular application is the valve flow characteristics in steady flow, and its dynamic characteristics in unsteady flow operation. With regards to steady flow valve Characteristics, current models for the determination of the check valve open angle versus mean flow velocity are based on semi-empirical data obtained from water tests, which were found to deviate from measurements involving fluids of relatively higher compressibility. This paper presents results of steady flow testing of an NPS 4 swing type check valve in air. Mean flow velocities versus disk angles were measured together with several local pressure measurements at the back side of the valve disk. Comparison of these results with the EPRI model and Rahmeyer’s model revealed that these two models underestimate the mean flow velocity for a given disk angle in air. A model was thus developed based on further refinement of Rahmeyer’s model, but more suitable for fluids of relatively higher compressibility, and accounts for both torque contributions: (i) from jet velocity impingement (Kv), and (ii) from back pressure distribution (Kp). The work presented here points out the need for better design of the disk shape, particularly at the lower lip, and/or the valve body in order to create a lower disk back pressure to improve the disk lifting torque at lower mean flow velocity.


Author(s):  
Ronald Farrell ◽  
L. Ike Ezekoye ◽  
Mark Rain

Computational Fluid Dynamics (CFD) is increasingly being used as a reliable method for determining flow characteristics of a wide range of flow situations. This paper presents an investigation on the application of CFD to characterize the opening and closing of check valves. Specifically, using CFD results, a procedure was developed to determine valve flow coefficients (CV) as a function of disk lift positions as well as to determine the flow rate required to achieve full open or predict intermediate disk lift positions. The method could be used for a wide range of check valves such as swing check valves, lift check valves, tilting disk check valves, or inline check valves. Using CFX which is a part of the ANSYS suite of finite element programs, examples of the predictive nature of CFD to characterize check valve performance are presented to address swing check and lift check valve designs. It is shown that balancing flow-induced forces on the disk and considering the disk assembly weight in the process is sufficient to model the valve lift behavior. Analysis results from this approach were compared with available test data of the modeled valves. The comparison showed good agreement, thus validating that both flow coefficients (CV) and flow rates across the valves at different disk lift positions can be reasonably predicted with this approach. The results of this study suggest that this approach can be used for valve design optimization and flow analysis of check valves. However, it should be pointed out that CFD is an evolving technology and is not a substitute for testing. The use of this tool compliments testing and, if carefully managed, can save valve development cost.


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