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Numerical Simulation of Internal Flow Field in Two Types of nozzle of Police Pulsed Anti-riots Water Cannon

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Numerical Simulation of Internal Flow Field in Two Types of ...

Computational Analysis of Flow Field on the Propulsion nozzle of a Micro-Turbojet Engine

2010 3rd IEEE International Conference on Computer Science and Information Technology—ICCSIT 2010

作者： ZHAN Ren-Jun Key Laboratory of Non-lethal Weapons of APF, Engineering College of APF, Xi’an 710086,China WANG Song Key Laboratory of Non-lethal Weapons of APF, Engineering College of APF, Xi’an 710086,China LIU Lei Key Laboratory of Non-lethal Weapons of APF, Engineering College of APF, Xi’an 710086,China

Two types of new-style nozzle are designed according to jet structure of Police Pulsed Anti-riots Water Cannon, and the LES model of Fluent6.2.16 is used for simulation. The result shows that the maximum velocity value would happen in the shrinking section, and the velocity and pressure would change rapidly. The jet could be accelerated because of the L of nozzle, so nozzle is better than nozzle at the area of increasing inlet velocity, and this would have a good use of increasing the maximum range of water cannon. The conclusion in this article would surely have action to direct the design of the experimental model.

关键词： Police Pulsed anti-riots water cannon nozzle numerical simulation maximum range

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Engineering（科研） 2012年第1期4卷 1-5页

作者： Jorge Luis Garrido-Téllez Miguel Toledo-Velázquez Samuel Alcántara-Montes José ángel L. Ortega-Herrera Arturo Reyes-León 不详

The purpose of this paper is to analyze the flow field on the propulsion nozzle of a micro-turbojet engine in function of the velocity. The 2D axisymmetric numerical simulation was made by using commercial software FLUENT?. A micro-turbojet engine was also employed for this study and it has the following characteristics: 100 N thrust, 130,000 rpm, mass flow rate 0.2650 kg/s, weight 1.2 kg. This engine is operating in Mexico city under the following conditions: P0, 78,000 Pa T0, 300 K, πc, 2.1 and a turbine entry temperature of 1000 K;it is considered that the nozzle is not choked. For this study, the viscous standard k- model, a semi-empirical model based on transport model equations for the turbulent kinetic energy (k) and its dissipation rate, is used. The transport model equation for k is derived from the ex-act equation, while the transport model equation for is obtained by using physical reasoning and bears resemblance to its mathematically exact counterpart. The employed grids are structured and the boundary conditions are obtained from a thermodynamic analysis. The results that are obtained show an increment of the velocity of 6.25% to the exit propulsion nozzle.

关键词： Propulsion nozzle Model Transport Equation Numerical Simulation Small Micro Turbine

Limits of Riemann Solutions for Isentropic MHD in a Variable Cross-Section Duct as Magnetic Field Vanishes

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Chinese Annals of Mathematics,Series B 2024年第4期45卷 637-660页

作者： Wancheng SHENG Tao XIAO Department of Mathematics Shanghai University Shanghai Aircraft Design and Research Institute

The stability for magnetic field to the solution of the Riemann problem for the polytropic fluid in a variable cross-section duct is discussed. By the vanishing magnetic field method, the stable solutions are determined by comparing the limit solutions with the solutions of the Riemann problem for the polytropic fluid in a duct obtained by the entropy rate admissibility criterion.

关键词： Variable duct Magnetogasdynamics Riemann problem Stability Vanishing magnetic field method ELEMENTARY WAVE INTERACTIONS FLUID EQUATIONS nozzle FLOWS

TRANSONIC SHOCK SOLUTIONS TO THE EULER SYSTEM IN DIVERGENT-CONVERGENT nozzleS

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Acta Mathematica Scientia 2022年第4期42卷 1536-1546页

作者：段犇兰傲罗珍 School of Mathematical Sciences Jilin UniversityChangchun 130012 China School of Mathematics Dalian University of TechnologyDalian116024China School of Mathematical Sciences Xiamen UniversityXiamen 361005China

In this paper,we study the transonic shock solutions to the steady Euler system in a quasi-one-dimensional divergent-convergent *** a given physical supersonic inflow at the entrance,we obtain exactly two non-isentropic transonic shock solutions for the exit pressure lying in a suitable *** addition,we establish the monotonicity between the location of the transonic shock and the pressure downstream.

关键词： Euler system transonic shocks steady solutions nozzle

Three-dimensional flow field simulation of steady flow in the serrated diffusers and nozzles of valveless micro-pumps

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Journal of Hydrodynamics 2019年第2期31卷 413-420页

作者： Ying-hua Xu Wei-ping Yan Kai-rong Qin Tun Cao School of Energy and Power Engineering Dalian University of TechnologyDalian 116024China School of Optoelectronic Engineering and Instrumentation Science Dalian University of TechnologyDalian 116024China

This paper presents a three-dimensional flow field simulation of the steady flows through diffusers and nozzles with straight or serrated-sided walls to analyze the effect of the channel structure on the flow *** pressure and velocity profiles in the diffusers and the nozzles as well as the net volumetric flow rate are *** simulation demonstrates that the pressure and velocity profiles in the serrated diffuser/nozzles are more complicated than those with the straight-sided wall,while the net steady flow rate with the straight-sided wall increases monotonically with the increase of the pressure difference,the steady flow rate with serrated sided walls increases gradually to reach a maximum and then decreases with the increase of the pressure *** results suggest that the number of the sawteeth plays a significant role in optimizing the design of serrated diffusers and nozzles for improving the transport efficiency of valveless micro-pumps.

关键词： Valveless micro-pump steady flow diffuser and nozzle serrated-sided wall three-dimensional flow field simulation

Combustion performance of nozzles with multiple gas orifices in large ladles for temperature uniformity

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Journal of Iron and Steel Research(International) 2018年第4期25卷 387-397页

作者： Fei Yuan Hong-bing Wang Pei-ling Zhou Anojun Xu School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing Beijing 100083 China School of Computer and Communication Engineering University of Science and Technology Beijing Beijing 100083 China State Key Laboratory of High-Efficient Mining and Safety of Metal Mines Ministry of Education University of Science and Technology Beijing Beijing 100083 China

In order to improve the baking temperature uniformity of the large ladle in steelmaking plants, the flame combustion characteristics of nozzles with different inner structures were numerically simulated with the finite volume method code Fluent. The flow field and premixed combustion reaction inside and outside the nozzle with multiple gas orifices were exhibited. Meanwhile, the influences of the gas injecting angle and the number of gas orifices on temperature, velocity, and pressure fields were studied. The results show that the flame length and width at the rear of flame temperature field reach the maximum values in the nozzle with the gas injecting angle of 20° and 4 gas orifices for the control of premixed combustion inside the nozzle, which could provide better temperature uniformity in ladles. The length of the 1273 K isothermal surface is 4.89 m, and the cross-section area at 4 m away from the outlet of the nozzle is 0.13 m2. The pressure losses of different types of nozzles range from 112.2 to 169.4 Pa and decrease with the decrement in gas injecting angle and the number of gas orifices. The ladle bottom preheating temperature is increased by 320-360 K for the optimized nozzle. The inner surface temperature differences between wall and bottom of the ladle are less than 10%. There is good baking temperature uniformity after the application of optimum structurally designed nozzles.

关键词： Ladle nozzle Preheating Flame Combustion performance Gas orifice Temperature uniformity

DRILLING CHARACTERISTICS OF COMBINATIONS OF DIFFERENT HIGH PRESSURE JET nozzleS

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Journal of Hydrodynamics 2011年第3期23卷 384-390页

作者： ZHANG Yu-ying LIU Yong-wang XU Yi-ji REN Jian-hua College of Petroleum Engineering China University of Petroleum （East China） Dongying 257061 China

The high speed fluid jet for directly or indirectly breaking rock is one of the most effective ways to improve the deep penetration rate. In order to maximize the efficiency of energy use, the flow characteristics of different combinations of high pressure jet nozzles are analyzed through numerical simulations. According to the velocity vectors at the bottom and the bottom hole pressure diagram, the effects of the high pressure nozzle combinations on the flow structure and the penetration rate are analyzed. It is shown that the combination of three vertical edge nozzles is very efficient, but inefficient in cleaning the bottom hole and eroding the wall. The jet velocity is 400 m/s and the radius is 5 mm, with a center nozzle added, the problem can be solved, but the high-pressure fluid displacement would increase. The center nozzle＇s jet velocity is 200 m/s and the radius is 8 ram, the combination of two vertical edge nozzles and a center tilt nozzle or that of a vertical edge nozzle and a center tilt nozzle would provide a flow structure favorable for drilling. The angle of inclination is 10°. To take advantage of high pressure jet energy to improve the efficiency of drilling, it is important to select a suitable nozzle combination according real conditions.

关键词： Rate Of Penetration (ROP) rock breaking high pressure jet nozzle combination numerical simulation energy use

Numerical simulation and experimental research on oscillation performance of disc-type jet oscillator

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Chinese Journal of Aeronautics 2023年第10期36卷 182-193页

作者： Wutekuer NUERMAIMAITI Xuewu LIU Pengze YAN Zongrui WANG Dapen HU School of Chemical Engineering Dalian University of TechnologyDalian 116024China

Based on active flow control technology,the two wall jets attached to a standard cylindrical surface due to the Coanda effect will output a detached jet when they *** direction of the output jets produced by this collision is very sensitive to small changes in the two wall ***,a new type of curved-wall supersonic compressible disc-type jet oscillator is proposed by using the oscillating feedback jet as the source of wall *** monitoring the internal flow field,the jet core’s pressure attenuation,the jet’s amplitude,and the wall pressure are *** results show that the disc-type jet oscillator model with a double-bend inlet has the best *** adding a multi-pipe outlet structure to the model,the oscillators with various disc diameters were simulated at different inlet pressures and air inlet frequencies to the wall-off control *** oscillation performance of the disc jet oscillator is better when the diameter of the disc is 32 mm and 20 mm,and the included angle between the wall-off control port and the horizontal direction is 45°.Two kinds of oscillators of the same diameter as the model are experimentally studied,and the results prove the feasibility of the disc-type jet oscillator.

关键词： Flow control nozzle Oscillations CFD Oscillating flow

Droplet spectra and high-speed wind tunnel evaluation of air induction nozzles

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Frontiers of Agricultural Science and Engineering 2018年第4期5卷 442-454页

作者： Qing TANG Liping CHEN Ruirui ZHANG Min XU Gang XU Tongchuan YI Bin ZHANG Beijing Research Center of Intelligent Equipment for Agriculture Beijing Academy of Agriculture and Forestry SciencesBeijing 100097China National Research Center of Intelligent Equipment for Agriculture Beijing 100097China Beijing Key Laboratory of Intelligent Equipment Technology for Agriculture Beijing 100097China

A series of air induction nozzles were tested in a high-speed wind *** size spectra were measured for four air induction nozzles(IDK-120-01,IDK-120-02,IDK-120-03 and IDK-120-04)each at three spray pressures(0.3,0.4 and 0.5 MPa)and seven different air velocities(121.7,153.4,185.5,218.4,253.5,277.5 and 305.5 km·h^(-1)).The measurement distance(0.15,0.25 and0.35 m)from the nozzle orifice was found to be important for the atomization of the *** response surface method was used to analyze the experimental *** results indicated that Dv_(0.1)and Dv_(0.5)of the droplets decreased quasi-linearly with increased wind speed,while Dv_(0.9)was affected by the quadratic of wind ***_(0.1),Dv_(0.5)and Dv_(0.9)of the droplets were all proportional to the orifice size,and were not markedly influenced by the spray *** percentage of the spray volume consisting of droplets with a diameter below 100 mm(%<100 mm)was found to be quadratically related to wind speed,and was not markedly influenced by the spray pressure and orifice ***,the effect of the orifice size on the %<200 mm could not be ignored.

关键词： air induction nozzle wind tunnel aerial spray droplet size spectra