scholarly journals Numerical study of the switching mechanism of a jet valve using the meshless method

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110300
Author(s):  
Jun Zhang ◽  
Yuanding Wang ◽  
Junjie Tan ◽  
Guiping Zhu ◽  
Jing Liu
Keyword(s):  
Meshless Method ◽  
Optimization Design ◽  
Moving Boundary ◽  
Numerical Study ◽  
Applied Pressure ◽  
Jet Flow ◽  
Vital Role ◽  
Switching Mechanism ◽  
Orbit Control ◽  
Force Direction

This study numerically investigates fluid dynamics of a jet flow at supersonic speed. The meshless method and the overlapping point cloud method are used to handle the moving boundary problems. The interaction between the jet flow and a moving ball-shaped plug is numerically solved, which has been rarely done in the published literature. The switching mechanism of a novel designed jet valve in an attitude and orbit control system (AOCS) is analyzed. It is found out that applied pressure to the control inlets of the jet valve must be high enough in order to successfully drive the plug to move and subsequently change the force direction acting on the jet valve. Then the switching mechanism of AOCS can be triggered. The initial fluid condition also plays a vital role and it significantly influences the response time of the switch. This study explores the underlying physics of the jet flow on its deflection, wall attachment, and interaction with the ball-shaped plug. It contributes to the optimization design of the jet valve in the AOCS with a fast and efficient response.

Numerical study of multi-dimensional hyperbolic telegraph equations arising in nuclear material science via an efficient local meshless method

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Imtiaz Ahmad ◽  
Aly R. Seadawy ◽  
Hijaz Ahmad ◽  
Phatiphat Thounthong ◽  
Fuzhang Wang
Keyword(s):  
Meshless Method ◽  
Material Science ◽  
Numerical Study ◽  
Research Work ◽  
Time Integration ◽  
Three Dimensional ◽  
Nuclear Material ◽  
Telegraph Equations ◽  
Model Equations ◽  
Derivatives Of

Abstract This research work is to study the numerical solution of three-dimensional second-order hyperbolic telegraph equations using an efficient local meshless method based on radial basis function (RBF). The model equations are used in nuclear material science and in the modeling of vibrations of structures. The explicit time integration technique is utilized to semi-discretize the model in the time direction whereas the space derivatives of the model are discretized by the proposed local meshless procedure based on multiquadric RBF. Numerical experiments are performed with the proposed numerical scheme for rectangular and non-rectangular computational domains. The proposed method solutions are converging quickly in comparison with the different existing numerical methods in the recent literature.

Numerical study of jet flow generated by impact on weakly compressible liquid

2006 ◽  
Vol 18 (3) ◽  
pp. 032108 ◽  
Author(s):  
Alexander A. Korobkin ◽  
Alessandro Iafrati
Keyword(s):  
Numerical Study ◽  
Jet Flow ◽  
Compressible Liquid ◽  
Weakly Compressible

Numerical Study on 3D Coupled Heat Transfer of Thrust Chamber with Regenerative Cooling

2011 ◽  
Vol 52-54 ◽  
pp. 1057-1061
Author(s):  
Tao Nie ◽  
Wei Qiang Liu
Keyword(s):  
Heat Transfer ◽  
Optimization Design ◽  
Numerical Study ◽  
Computing Time ◽  
Three Dimensional ◽  
Geometrical Model ◽  
Performance Estimation ◽  
Transfer Model ◽  
Empirical Formulas ◽  
Coupled Heat Transfer

To obtain temperature distribution in regenerative-cooled liquid propellant rocket nozzle quickly and accurately, three-dimensional numerical simulation employed using empirical formulas. A reduced one-dimensional model is employed for the coolant flow and heat transfer, while three dimensional heat transfer model is used to calculate the coupling heat transfer through the wall. The geometrical model is subscale hot-firing chamber. The numerical results agree well with experimental data, while temperature field in nozzle obtained. In terms of computing time and accuracy of results, this method can provide a reference for optimization design and performance estimation.

scholarly journals A Meshless Solution Method for Unsteady Flow with Moving Boundary

2014 ◽  
Vol 6 ◽  
pp. 209575 ◽  
Author(s):  
Jun Zhang ◽  
Deng-feng Ren ◽  
Xin-jian Ma ◽  
Jun-jie Tan ◽  
Xiao-wei Cai
Keyword(s):  
Flow Field ◽  
Unsteady Flow ◽  
Meshless Method ◽  
Moving Objects ◽  
Moving Boundary ◽  
Initial Position ◽  
Piston Problem ◽  
Naca0012 Airfoil ◽  
Moving Body ◽  
Moving Points

Using the concept of overlapping mesh method for reference, a new method called as Overlapping Clouds of Points Method (OCPM) is firstly proposed to simulate unsteady flow with moving boundary problems based on meshless method. Firstly, a set of static background discrete points is generated in the whole calculation zone. Secondly, moving discrete points are created around moving body. According to the initial position of moving object in the flow field, the two sets of discrete points can be overlapped. With the motion of moving objects in the calculation field, moving discrete points around the moving body will inherently move. The exchange of flow field information between static points and moving points is realized by the solution of the clouds of points made up of static and moving discrete points using weighted meshless method nearby overlapping boundary. Four cases including piston problem, NACA0012 airfoil vibration flow around a moving sphere in supersonic and multibody separation are given to verify accuracy and practicability of OCPM. The numerical results agree well with exact solution and experimental results, which shows that the proposed OCPM can be applied to the simulation of unsteady flow problem.

Numerical Study of a Turbulent Offset Jet Flow

2015 ◽  
pp. 703-711 ◽  
Author(s):  
Ali Assoudi ◽  
Sabra Habli ◽  
Nejla Mahjoub Saïd ◽  
Philippe Bournot ◽  
Georges Le Palec
Keyword(s):  
Numerical Study ◽  
Jet Flow ◽  
Offset Jet

scholarly journals A Numerical Study of Axisymmetric Wave Propagation in Buried Fluid-Filled Pipes for Optimizing the Vibro-Acoustic Technique when Locating Gas Pipelines

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3707 ◽  
Author(s):  
Liu ◽  
Habibi ◽  
Chai ◽  
Wang ◽  
Chen
Keyword(s):  
Wave Motion ◽  
Numerical Study ◽  
Acoustic Method ◽  
Vital Role ◽  
Pipe Material ◽  
Water Pipes ◽  
Axisymmetric Wave ◽  
Pipeline Systems ◽  
Buried Gas Pipeline ◽  
Effective Radiation

Buried pipeline systems play a vital role in energy storage and transportation, especially for fluid energies like water and gas. The ability to locate buried pipes is of great importance since it is fundamental for leakage detection, pipeline maintenance, and pipeline repair. The vibro-acoustic locating method, as one of the most effective detection technologies, has been studied by many researchers. However, previous studies have mainly focused on vibro-acoustic propagation in buried water pipes. Limited research has been conducted on buried gas pipes. In this paper, the behavior of gas-dominated wave motion will be investigated and compared against water-dominated wave motion by adapting an established analytical model of axisymmetric wave motion in buried fluid-filled pipes. Furthermore, displacement profiles in spatial domain resulting from gas-dominated wave in buried gas pipeline systems will be analyzed, and the effects of pipe material, soil property, as well as mode wave type will be discussed in detail. An effective radiation coefficient (ERC) is proposed to measure the effective radiation ability of gas-dominated wave and water-dominated wave. It is observed that the gas-dominated wave in gas pipes cannot radiate into surrounded soil as effectively as water-dominated wave in water pipes because of the weak coupling between gas and pipe-soil. In this case, gas-dominated wave may not be the best choice as the target wave for locating buried gas pipes. Therefore, the soil displacements result from the shell-dominated wave are also investigated and compared with those from gas-dominated wave. The results show that for buried gas pipes, the soil displacements due to radiation of shell-dominated wave are stronger than gas-dominated wave, which differs from buried water pipe. Hence, an effectively exciting shell-dominated wave is beneficial for generating stronger vibration signals and obtaining the location information. The findings of this study provide theoretical insight for optimizing the current vibro-acoustic method when locating buried gas pipes.

A comprehensive numerical study of jet flow impingement over flat plates at varied angles

2001 ◽  
Author(s):  
Junxiao Wu ◽  
Lin Tang ◽  
Edward Luke ◽  
Xiao-Ling Tong ◽  
Pasquale Cinella
Keyword(s):  
Numerical Study ◽  
Jet Flow ◽  
Flat Plates
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