Flow Analysis of Spray Jet and Direct Jet Nozzle for Fire Water Monitor

2010 ◽  
Vol 139-141 ◽  
pp. 913-916 ◽  
Author(s):  
Guo Liang Hu ◽  
Wei Gang Chen ◽  
Zhi Gang Gao
Keyword(s):  
Flow Analysis ◽  
Flow Characteristics ◽  
Flow Simulation ◽  
Jet Flow ◽  
Extended Length ◽  
Jet Nozzle ◽  
Simulation Results ◽  
Steady Velocity ◽  
Nozzle Structure

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.

scholarly journals Defects Analysis Using E Foundry and Flow Simulation for Crank Case Casting

10.29007/xl1j ◽  
2018 ◽  
Author(s):  
Yogin Vekariya ◽  
Trushant Desai ◽  
Rakesh Barot ◽  
Balkrushna Sharma
Keyword(s):  
Molten Metal ◽  
Computer Technology ◽  
Metal Flow ◽  
Flow Analysis ◽  
Flow Characteristics ◽  
Flow Simulation ◽  
Casting Process ◽  
Gating System ◽  
Dross Formation ◽  
Defects Analysis

Casting process deals with the metal in the molten state. When the molten metal is poured into the mold box, Smooth and turbulence less flow with appropriate velocity is need to be ensured. Type of flow while pouring the molten metal has significant influence on the end characteristics of casting. Inefficient metal flow can result in error beyond altering the desired characteristics of casting. Dross formation while pouring the metal has direct connection with the type of flow of molten metal. In short, one cannot neglect the flow of molten metal on other hand expecting sound casting formation. Gating characteristics directly deals with the type of flow expected while pouring. To provide desired flow is one of the functions of efficient gating system. But it is very difficult to consider the flow characteristics while actually designing the gating system. Computer technology has taken leap to aid foundry engineer in control of metal flow. Simulation soft-wares have been equipped with provision of flow analysis while designing the Gating system.

Study on the eccentric jet-flow characteristics induced by the opening regulation with a gate valve

2021 ◽  
pp. 095440622199488
Author(s):  
De-sheng Chen ◽  
Yong-xiang Wang ◽  
Qi Liu ◽  
Zhe Lin ◽  
Zu-chao Zhu ◽  
...  
Keyword(s):  
Cross Sections ◽  
Axial Velocity ◽  
Gate Valve ◽  
Flow Characteristics ◽  
Flow Simulation ◽  
Jet Flow ◽  
Valve Opening ◽  
Induced Flow ◽  
And Control ◽  
Small Valve

Valve-induced flow characteristics were often concerned in many fluid transportation and control industries. In this paper, the eccentric jet-flow characteristics induced by a gate valve have been studied by considering the influence of valve opening regulation. The experimental setup of monitoring the downstream pressures along the pipeline was developed, and corresponding numerical simulation was employed. The downstream-monitoring pressure distribution caused by valve opening regulation was investigated to verify the flow simulation. The generation mechanism of eccentric jet-flow was revealed as a strong pressure gradient caused by the throttling effect at the valve throat. It was found that the eccentric jet-flow evolved in the pipeline was accompanied by shearing vortices, extremely under a small valve opening. The pressure and axial velocity distributions at various downstream cross-sections of the eccentric jet-flow evolving in the pipeline were analyzed. The axial velocities on four monitoring lines in downstream cross-sections were extracted, and the radial location of the maximum axial velocity was derived to assess the eccentric characteristics of jet-flow. A dimensionless parameter of velocity eccentric ratio was introduced to quantify the eccentric intensity of the evolving jet-flow in the downstream pipeline, and its correlation with the pipeline length could be adequately expressed by a natural decreasing exponential curve via fitting analysis. By virtue of that correlation, the critical pipeline length was proposed that can be used as the judgment to the terminal of the eccentric jet-flow evolving in the downstream pipeline. This study was helpful to characterize the valve-induced flow characteristics in scientific research and provide useful insight into fluid and mechanical engineering.

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
Keyword(s):  
Cfd Simulation ◽  
Flow Analysis ◽  
Flow Characteristics ◽  
Check Valve ◽  
The Body ◽  
Cfd Simulations ◽  
Valve Body ◽  
Main Research ◽  
Flow Channels ◽  
Simulation Results

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%.

scholarly journals Estimation of Injection Molding Process for a Thin Fresnel lens By Plastic Flow Simulation

2019 ◽  
Vol 8 (10) ◽  
pp. 3276-3282
Keyword(s):  
Injection Molding ◽  
Plastic Flow ◽  
Flow Analysis ◽  
Flow Simulation ◽  
Fresnel Lens ◽  
Injection Molding Process ◽  
Molding Process ◽  
Manufacturing Defects ◽  
Simulation Results ◽  
Plastic Parts

This paper is based on the plastic flow simulation of a thin Fresnel lens to estimate the injection molding process. Nowadays Fresnel lenses are made of transparent plastics materials instead of silica-based glass to reduce handling and processing cost. For mass manufacturing of plastic parts, the injection molding process is best suited. Thus in this study plastic flow analysis of a thin Fresnel lens is carried for the evaluation of injection molding process. Plastic flow analysis helps in estimating how molten plastic will flow during the process Plastic flow analysis is also very helpful in evaluating the manufacturing defects such as air traps and weld lines without real-time experimentation. The simulation results evaluate the values of the parameters such as fill time, filing pressure, pack pressure, etc. Also, the manufacturing defects observed by the simulation results are reasonable and met the design requirement.

Study on Left-Turning Traffic Flow Characteristics under Different Pedestrian Violation Rates at Signalized Intersection

2015 ◽  
Vol 744-746 ◽  
pp. 2053-2058
Author(s):  
Chang Hai Wei ◽  
Yu Huan Wang ◽  
Xu Wang
Keyword(s):  
Traffic Flow ◽  
Flow Characteristics ◽  
Flow Simulation ◽  
Signalized Intersection ◽  
Traffic Flow Simulation ◽  
Pedestrian Accidents ◽  
Traffic Flow Characteristics ◽  
Simulation Results ◽  
Update Rules ◽  
The Impact

Conflicts between left-turning vehicles and pedestrians are common at signalized intersection in most developing countries. A new cellular automaton model is proposed to characterize left-turning traffic flow. New status update rules and driving behavior in affected areas and nonaffected areas are defined. Indexes of density, average speed and volume under different pedestrian violation rates are compared to quantify the impact of conflicts on left-turning traffic flow. Simulation results illustrate that pedestrian violations have a great impact on left-turning traffic flow and capacity of the intersection. Therefore, taking countermeasures will improve vehicle maneuvers, reduce the number of pedestrian accidents and increase the capacity of the intersection.

Flow Analysis of a Shrouded Aerosol Sampling Inlet

2013 ◽  
Vol 347-350 ◽  
pp. 3903-3906
Author(s):  
Bao Qing Wang ◽  
Shu Yao ◽  
De Qing Wang ◽  
Zhi Peng Bai ◽  
Xin Hua Wang
Keyword(s):  
High Speed ◽  
Cfd Simulation ◽  
Flow Analysis ◽  
Flow Characteristics ◽  
Flow Simulation ◽  
Aerosol Sampling

A shrouded aerosol sampling inlet has been designed from high-speed aircraft. The sampling inlet was conducted using the CFD to perform a flow simulation. The shroud diameter is 150 mm. The inlet is located 180mm from the shroud entrance plane. The shroud is 300 mm long. Results are presented graphically, showing the shrouds have provided significant improvements in flow characteristics. Straighten the streamlines of gas of sampling inlet for flow angles up to five degrees. It is suggested that CFD simulation can be useful for improving the optimum a shrouded aerosol sampling inlet.

scholarly journals Flow Simulation Using 2D Hydrodynamic Model at the Palu Estuary Based on National DEM (DEMNAS) Source Data

2021 ◽  
Vol 16 (6) ◽  
pp. 709-715
Author(s):  
Muh. Galib Ishak ◽  
I Gede Tunas ◽  
Rudi Herman ◽  
Setiyawan ◽  
Yassir Arafat
Keyword(s):  
Survey Data ◽  
Flow Characteristics ◽  
Flow Simulation ◽  
Poor Performance ◽  
Time Range ◽  
Observation Data ◽  
Discharge Data ◽  
Geometry Model ◽  
Simulation Results ◽  
Hourly Observation

2D hydrodynamic simulation is very important to be performed to interpret the flow characteristics of a river segment. The success of this simulation is determined not only by the input boundary data, but also by the quality of the data used to create the geometry model, such as terrestrial survey data, digital elevation model (DEM) or data from other sources. This paper aims to assess the use of National DEM data (DEMNAS) as the basis for constructing a 2D geometry model for flow simulation in the downstream segment of the Palu River, Sulawesi, Indonesia. The simulation results using this DEM were compared with simulations based on geometry generated from terrestrial survey data. The hourly observation discharge data at Point P3 and tidal observation data at Point P1 in the period March 17th – 18th, 2021 were assigned as the inputs at the upstream and downstream boundaries, respectively. The performance of the two model scenarios was evaluated by comparing the water surface elevation observed and simulated during the time range at Point P2 using the efficiency of Nash–Sutcliffe (NSE). The simulation results show that the two geometry-forming data provide different performance against NSE. The terrestrial survey data shows a fairly good performance, while the DEMNAS data indicates a poor performance with a negative NSE. Based on the NSE of these two scenarios, it can be interpreted that the DEMNAS data is still not sufficient to construct the model geometry for the case in this area. This is not only related to the DEMNAS resolution, especially the vertical resolution, but is also related to the very low topographical slope in the estuary of the river. However, the use of these data in areas of higher slope can be re-evaluated.

scholarly journals Random pore structure and REV scale flow analysis of engine particulate filter based on LBM

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 881-896
Author(s):  
Chunrui Wu ◽  
Tiechen Zhang ◽  
Jiale Fu ◽  
Xiaori Liu ◽  
Boxiong Shen
Keyword(s):  
Single Channel ◽  
Flow Analysis ◽  
Flow Characteristics ◽  
Axial Direction ◽  
Particulate Filter ◽  
Random Structure ◽  
Structure Generation ◽  
Inlet Flow ◽  
Random Structures ◽  
Boltzmann Method

Abstract In this article, lattice Boltzmann method (LBM) is used to simulate the multi-scale flow characteristics of the engine particulate filter at the pore scale and the representative elementary volume (REV) scale, respectively. Four kinds of random wall-pore structures are considered, which are circular random structure, square random structure, isotropic quartet structure generation set (QSGS), and anisotropic QSGS, with difference analysis done. In terms of the REV scale, the influence of different inlet flow velocities and wall permeabilities on the flow in single channel is analyzed. The result indicates that the internal seepage laws of random structures constructed in this article and single channel are in accordance with Darcy’s law. Circular random structure has better permeability than square random structure. Isotropic QSGS has better fluidity than anisotropic one. The flow in single channel is similar to Poiseuille flow. The flow lines in the channel are complicated and a large number of vortices appear at the ends of channel with high inlet flow rate. With the increase of inlet velocity, the static pressure in channel gradually increases along the axial direction as well as the seepage velocity. The temperature field in the channel becomes more uniform as the flow velocity increases, and the higher temperature distribution appears on the wall of the porous media.

A NUMERICAL STUDY ON THE HEMODYNAMIC AND SHEAR STRESS OF DOUBLE ANEURYSM THROUGH S-SHAPED VESSEL

2015 ◽  
Vol 27 (04) ◽  
pp. 1550033 ◽  
Author(s):  
Mahdi Halabian ◽  
Alireza Karimi ◽  
Borhan Beigzadeh ◽  
Mahdi Navidbakhsh
Keyword(s):  
Blood Flow ◽  
Mechanical Behavior ◽  
Numerical Study ◽  
Flow Characteristics ◽  
Flow Simulation ◽  
The Body ◽  
Sweep Angle ◽  
Abdominal Aortic ◽  
Hemodynamic Characteristics ◽  
Refined Meshes

Abdominal aortic aneurysm (AAA) is a degenerative disease defined as the abnormal ballooning of the abdominal aorta (AA) wall which is usually caused by atherosclerosis. The aneurysm grows larger and eventually ruptures if it is not diagnosed and treated. Aneurysms occur mostly in the aorta, the main artery of the chest and abdomen. The aorta carries blood flow from the heart to all parts of the body, including the vital organs, the legs, and feet. The objective of the present study is to investigate the combined effects of aneurysm and curvature on flow characteristics in S-shaped bends with sweep angle of 90° at Reynolds number of 900. The fluid mechanics of blood flow in a curved artery with abnormal aortic is studied through a mathematical analysis and employing Cosmos flow simulation. Blood is modeled as an incompressible non-Newtonian fluid and the flow is assumed to be steady and laminar. Hemodynamic characteristics are analyzed. Grid independence is tested on three successively refined meshes. It is observed that the abrupt expansion induced by AAA results in an immensely disturbed regime. The results may have implications not only for understanding the mechanical behavior of the blood flow inside an aneurysm artery but also for investigating the mechanical behavior of the blood flow in different arterial diseases, such as atherosclerosis.

Study on the Cyclic Loading Effects to the Railway Ballast

2013 ◽  
Vol 724-725 ◽  
pp. 1736-1739
Author(s):  
Xue Jun Wang ◽  
Bin Hua ◽  
Yi Lin Chi ◽  
Xue Yu Zhao ◽  
Fu Yu Li
Keyword(s):  
Cyclic Loading ◽  
Research Method ◽  
Flow Simulation ◽  
Railway Ballast ◽  
Compaction Rate ◽  
Simulation Process ◽  
Loading Effects ◽  
Simulation Results ◽  
Frequency Changes ◽  
Particle Flow Simulation

When ballast materials are subjected to cyclic loading, as a result, the change of particles micromechanical properties will lead to ballast degradation, permanent deformations on the railways step by step. In this paper, it presented a coupling discrete particle-flow simulation model of the railway ballast for cyclic tamping loading. Tamping frequency changes from 25HZ to 60HZ in numerical simulation process. Simulation results that the ballast compaction rate increases linearly with frequency up to a characteristic frequency 35HZ and then it declines in inverse proportion to tamping frequency. The aim of this paper is to study on the effects on the railway ballast under cyclic loading. The study shows that the discrete element method is a valid method for investigation of the microscopic properties of railway ballast now, while we have no other better research method.

Sign in / Sign up

Export Citation Format

Share Document