Transient flow field characteristic analysis of poppet valve based on dynamic mesh 6DOF technique

2015 ◽  
Author(s):  
Guo Xiao-xia ◽  
Huang Jia-hai ◽  
Quan Long ◽  
Wang Sheng-guo
Keyword(s):  
Flow Field ◽  
Transient Flow ◽  
Dynamic Mesh ◽  
Characteristic Analysis ◽  
Field Characteristic ◽  
Poppet Valve

A new dynamic mesh algorithm for studying the 3D transient flow field of tilting pad journal bearings

2016 ◽  
Vol 230 (12) ◽  
pp. 1470-1482 ◽  
Author(s):  
Mengxuan Li ◽  
Chaohua Gu ◽  
Xiaohong Pan ◽  
Shuiying Zheng ◽  
Qiang Li
Keyword(s):  
Flow Field ◽  
Equilibrium Position ◽  
Transient Flow ◽  
Journal Bearings ◽  
Dynamic Mesh ◽  
Static Equilibrium ◽  
Time Step ◽  
Tilting Pad ◽  
Grid Nodes ◽  
Tilting Pad Journal Bearings

A new dynamic mesh algorithm is developed in this paper to realize the three-dimensional (3D) computational fluid dynamics (CFD) method for studying the small clearance transient flow field of tilting pad journal bearings (TPJBs). It is based on a structured grid, ensuring that the total number and the topology relationship of the grid nodes remain unchanged during the dynamic mesh updating process. The displacements of the grid nodes can be precisely recalculated at every time step. The updated mesh maintains high quality and is suitable for transient calculation of large journal displacement in FLUENT. The calculation results, such as the static equilibrium position and the dynamic characteristic coefficients, are consistent with the two-dimensional (2D) solution of the Reynolds equation. Furthermore, in the process of transient analysis, under conditions in which the journal is away from the static equilibrium position, evident differences appear between linearized and transient oil film forces, indicating that the nonlinear transient calculation is more suitable for studying the rotor-bearing system.

Numerical Simulation Based on CFD for the Movement Field of the Hydraulic Poppet Valve

2012 ◽  
Vol 466-467 ◽  
pp. 1266-1270
Author(s):  
Xiong Shi ◽  
Jun Chen
Keyword(s):  
Numerical Simulation ◽  
Numerical Modeling ◽  
Flow Field ◽  
Numerical Method ◽  
Dynamic Mesh ◽  
Intake Rate ◽  
Poppet Valve ◽  
Concave Corner ◽  
Simulation Based ◽  
Movement Field

Based on the physical numerical modeling of the hydraulic poppet valve, the inside flow field was simulated by numerical method of the dynamic mesh technology of Fluent. The analysis results indicate that the intake rate and flux are reduced by minishing the poppet. And the eddy section’ s length of the intake and the concave corner of the valve core is gradually minished and disappeared at last.

Research of transient flow field real time interferogram acquisition system

2007 ◽  
Author(s):  
Jiao Liang ◽  
Yongying Yang ◽  
Dong Liu ◽  
Yongmo Zhuo ◽  
Jianhua Hui ◽  
...  
Keyword(s):  
Flow Field ◽  
Real Time ◽  
Transient Flow ◽  
Acquisition System

scholarly journals Role of Transient Characteristics in Fish Trajectory Modeling

2020 ◽  
Author(s):  
zhu gao ◽  
zu hao zhou ◽  
Helge I Andersson
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Turbulent Flow ◽  
Transient Flow ◽  
Simultaneous Recording ◽  
Fish Locomotion ◽  
Vertical Slot ◽  
Turbulent Flow Structure ◽  
General Method

In this paper, we analyzed the live fish trajectory recorded from an experiment in an experimental vertical slot fishway. Combined with a numerical simulation, we demonstrated that randomness shown in fish trajectory might not merely be attributed to fish's random choices in its swimming, also could be an adaption consequence to the bulk unsteady turbulent flow structure. Simple superposing the fish trajectory on the time-averaged flow field obtained either by interpolating on discrete point measurements or numerical simulation is not an ideal method for fish movement description in fishway engineering. How to model the fish paths in transient flow and the necessity of simultaneous recording of the flow field and the fish locomotion are challenging topics. The suggested spectrum analysis of the flow field may provide a new general method to reproduce the fish trajectory in a complex turbulent flow.

scholarly journals Calibration Routine for Quantitative Three-Dimensional Flow Field Measurements in Drying Polymer Solutions Subject to Marangoni Convection

2019 ◽  
Vol 3 (1) ◽  
pp. 39
Author(s):  
Max Tönsmann ◽  
Fabian Kröhl ◽  
Philipp Cavadini ◽  
Philip Scharfer ◽  
Wilhelm Schabel
Keyword(s):  
Flow Field ◽  
Particle Tracking Velocimetry ◽  
Transient Flow ◽  
Marangoni Convection ◽  
Three Dimensional ◽  
Field Measurements ◽  
Calibration Procedure ◽  
Cover Glass ◽  
Spread Function ◽  
Multifocal Lens

Surface-tension induced flows may have a significant impact on the surface topography of thin films or small printed structures derived from polymer solution processing. Despite a century of research on Marangoni convection, the community lacks quantitative experimental flow field data, especially from within drying solutions. We utilize multifocal micro particle tracking velocimetry (µPTV) to obtain these data and show a calibration routine based on point spread function (PSF) simulations as well as experimental data. The results account for a varying sample refractive index, beneficial cover-glass correction collar settings as well as a multifocal lens system. Finally, the calibration procedure is utilized exemplarily to reconstruct a three-dimensional, transient flow field within a poly(vinyl acetate)-methanol solution dried with inhomogeneous boundary conditions.

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