Numerical Simulation of High Velocity Waterjet Characteristics and Impact Pressure

2011 ◽  
Vol 109 ◽  
pp. 551-556 ◽  
Author(s):  
Qun Luo ◽  
Kai He ◽  
He Mao ◽  
Jiu Hua Li ◽  
Quan Chang Li ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Pressure Distribution ◽  
High Velocity ◽  
Impact Pressure ◽  
Hydrodynamic Characteristics ◽  
Initial Region ◽  
Mixture Flow ◽  
Incremental Sheet Metal Forming ◽  
Pump Pressure ◽  
The Impact

This paper presents a numerical simulation approach to analyze high velocity waterjet characteristics and impact pressure. For the complexity of waterjet formation in air, multiphase mixture flow model is used, and the simulation is performed in FLUNET software. The simulation includes the hydrodynamic characteristics and pressure distribution of high velocity waterjet in air. The decay of pressure at different distance along centerline under different pump pressure is analyzed and the length of the initial region of waterjet is determined. In addition, the impact pressure of waterjet at different stand-off distance is also simulated, and the impact pressure distribution and its changing tendency with the stand-off distance are obtained. This paper provides theoretical parameters for waterjet incremental sheet metal forming.

scholarly journals Impact pressure distribution of inverted arch plunge pool for large discharge

2019 ◽  
Vol 20 (1) ◽  
pp. 209-218
Author(s):  
Yu Wang ◽  
Yaan Hu ◽  
Jinde Gu ◽  
Yu Peng ◽  
Yang Xue
Keyword(s):  
Pressure Distribution ◽  
High Water ◽  
Impact Pressure ◽  
Engineering Practice ◽  
Plunge Pool ◽  
Novel Approach ◽  
Water Head ◽  
Relative Errors ◽  
The Impact ◽  
Large Discharge

Abstract In view of high water head and large discharge in the release structures of hydraulic projects, the inverted arch plunge pool has been put forward due to higher overload capability and stability. Impact pressure on the bottom is a serious concern in design safety precautions, however, the quantitative impact pressure distribution in the inverted arch plunge pool is not yet elucidated. In this study, a novel approach is presented to estimate the impact pressure of an inverted arch plunge pool. Impact pressure characteristics are experimentally investigated under different hydraulic conditions. The results detailed the effect of relative discharge coefficient and the deflection angle relative to the vertical central axis of the plunge pool bottom. The predicting formulas of impact pressure distribution are derived within small relative errors, and the proposed approaches have good applicability in three case studies. The achievements of this investigation are used to define issuance parameters relevant for engineering practice.

The Establishment of Ninety Degree Gas Elbow Pipes Internal Pressure Distribution Model

2014 ◽  
Vol 670-671 ◽  
pp. 696-699 ◽  
Author(s):  
Xiao Yang Lu ◽  
Yong Zhou ◽  
Shi Ying Chen ◽  
Xin Guang Li ◽  
Hong Liang Zhu
Keyword(s):  
Numerical Simulation ◽  
High Pressure ◽  
Internal Pressure ◽  
Pressure Distribution ◽  
High Velocity ◽  
Three Dimensional ◽  
Distribution Model ◽  
Geometrical Parameters ◽  
Maximum Relative Error ◽  
Nonlinear Fitting

According to the principle of harmonious dimensions, the qualitative distribution model of the internal pressure on elbow pipes were determined; Through FLUENT numerical simulation, the internal pressure were given under 96 kinds of gas fluid conditions; By analyzing the variation of the internal pressure with flow and geometrical parameters, the variation of the internal pressure distribution within the elbow pipes has been studied; By means of 1stOpt nonlinear fitting package, the formula of three-dimensional internal pressure distribution was determined; Compared with the numerical results, the maximum relative error is 0.012%. The formula provides theoretical bases for strength check, the transport pipeline and wall thickness design of the high pressure, high velocity elbow.

Numerical Hull Resistance and Hydrodynamic Characteristics of an Independently Rotating Multi-Hull Vessel

2019 ◽  
Author(s):  
Sharath Srinivasamurthy ◽  
Hiroshi Sakamoto ◽  
Tatsuo Nishikawa ◽  
Yasunori Nihei
Keyword(s):  
Numerical Simulation ◽  
Pressure Distribution ◽  
Cfd Simulation ◽  
Hydrodynamic Characteristics ◽  
Cfd Simulations ◽  
Basic Framework ◽  
Wave Patterns ◽  
Experimental Findings ◽  
Hydrodynamic Effects ◽  
Simulation Scheme

Abstract In this study, an attempt is made to understand the hydrodynamic characteristics of an automated multi-hull vessel named as Quadmaran. Firstly, a single hull of the Quadmaran vessel is considered and numerical CFD simulation is performed using OpenFOAM. Hull resistance predictions are compared with the experimental findings and numerical simulation is validated. After validating the simulation scheme, further CFD simulations are performed on two hulls with varying distance between them to understand the hydrodynamic characteristics of different configurations. Pressure distribution and wave patterns around the hulls are also summarized and discussed in the paper. Further, efforts are made to optimize the distance between the hulls for reducing hull resistance. A basic framework is suggested to carefully consider the hydrodynamic effects for multi-hull vessels.

scholarly journals High-Velocity Impact Performance of Aluminum and B4C/UHMW-PE Composite Plate for Multi-Wall Shielding

2020 ◽  
Vol 10 (2) ◽  
pp. 721 ◽  
Author(s):  
Yangyu Lu ◽  
Qingming Zhang ◽  
Yijiang Xue ◽  
Wenjin Liu ◽  
Renrong Long
Keyword(s):  
Numerical Simulation ◽  
High Velocity ◽  
Composite Plate ◽  
Composite Plates ◽  
Cylindrical Shape ◽  
High Velocity Impact ◽  
Velocity Impact ◽  
Impact Performance ◽  
Speed Range ◽  
The Impact

Three types of multi-wall shielding were experimentally investigated for their performances under the high-velocity impact of a cm-size cylindrical projectile by using a two-stage light-gas gun. The three shields contained the same two aluminum bumpers but different rear walls, which were 7075-T651 aluminum (Al) plate, boron carbide (B4C)/Al 7075-T651/Kevlar composite plate and B4C/ultra-high molecular weight polyethylene (UHMW-PE) composite plate. The impact test was carried out using a cylindrical shape of 6 g mass 7075-T651 Al projectile in a speed range (1.6 to 1.9 km/s) to achieve an effective shield configuration. A numerical simulation was undertaken by using ANSYS Autodyn-3D and the results of this were in good agreement with the experimental results. Meanwhile, both the experimental and the numerical simulation results indicated that B4C/UHMW-PE composite plates performed a better interception of the high-velocity projectiles within the specific speed range and could be considered as a good configuration for intercepting large fragments in shielding design.

scholarly journals Numerical and analytical simulation of ballistic projectile penetration due to high velocity impact on ceramic target

2020 ◽  
Vol 14 (54) ◽  
pp. 226-248
Author(s):  
Amin Moslemi Petrudi ◽  
Khodadad Vahedi ◽  
Masoud Rahmani ◽  
MohammadAli Moslemi Petrudi
Keyword(s):  
Numerical Simulation ◽  
High Velocity ◽  
High Performance ◽  
Ceramic Materials ◽  
Material Behavior ◽  
High Velocity Impact ◽  
Velocity Impact ◽  
Military Equipment ◽  
Equipment Construction ◽  
The Impact

Simulation and analysis of the projectile impact and penetration problem and its effects are among the practical topics that can be used to design bulletproof panel and military equipment, construction of impact and penetration resistant structures, design of projectiles with appropriate penetration strength and High performance noted. One of the most important parameters affecting penetration is the impact velocity of the projectile. The mechanism of penetration varies in different speed ranges. In this paper, Ansys Autodyn software is used for intrusion simulation. The simulation carried out in this study is based on the accuracy and physical conditions of the problem and the compatibility of numerical simulation with the governing analytical relationships indicates the validity and accuracy of the assumptions made in the simulation. In this study, we selected materials such as material behavior, grating, contact surfaces, and controls, as well as collision of the blunt projectile with angles of 0º,15º,30º,45º by of high velocity impact 1000 m/s with the same mass and diameter and shape of the projectile nose and properties. Ceramic materials are discussed. The result of the numerical simulation comparison shows relatively good agreement between them.

Influence of the Distribution of Dual Cascades on Double Vanes Based on the Solid-Liquid Two-Phase Flow

2015 ◽  
Vol 723 ◽  
pp. 186-189
Author(s):  
Fu Chun Liu ◽  
Jian Rong Zhang ◽  
Dong Wang
Keyword(s):  
Numerical Simulation ◽  
Pressure Distribution ◽  
Velocity Vector ◽  
Active Surface ◽  
Energy Performance ◽  
Phase Flow ◽  
Two Phase ◽  
Guide Vanes ◽  
Solid Liquid ◽  
The Impact

The relative positional relationship between the stay vanes and guide vanes is researched to analyze the impact on the hydraulic performance of the Turbine based on N-S equations and RNG k-ε turbulence model under the conditions of sandy water with the numerical simulation method.There are main five kinds of the relative positional relationship between the dual cascades is used to analyse the trends of the distribution about the pressure and velocity. The relative circumferential positions between the dual cascades have obviously effect on the flow verified.And the velocity vector and the pressure distribution on the surface of the guide vanes are studied further.The results show that energy performance is best if little circumferential position differences between the dual cascades in two typical conditions.However, thedistribution about the pressure and velocity is uneven on the active surface of guide vanes, exacerbating the local abrasion of the vanes.

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