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.

Three-Dimensional Numerical Analysis of Horizontal and Vertical Coalescence of Bubbles at Two Submerged Horizontal Orifices on the Wall

2019 ◽  
Author(s):  
Z. P. Li ◽  
L. Q. Sun ◽  
X. L. Yao ◽  
Y. Piao
Keyword(s):  
Numerical Simulation ◽  
Internal Pressure ◽  
Three Dimensional ◽  
Ventilation Rate ◽  
Smoothing Technique ◽  
Dimensional Model ◽  
Mesh Smoothing ◽  
Three Dimensional Model ◽  
Coalescence Time ◽  
Ventilation Rates

Abstract In the process of bubbling from two submerged adjacent orifices, bubbles coalescence becomes inevitable. But the study of the evolution and interaction of bubbles from submerged orifices is little, especially numerical simulation. In this paper, combined with mesh smoothing technique, mesh subdivision technique and the technique of axisymmetric coalescence and 3D coalescence, a three-dimensional model of bubbles coalescence at two submerged adjacent orifices on the wall is established by the boundary element method. Then, numerical simulations were carried out for horizontal and vertical coalescence before detachment. Finally, by changing the ventilation rate and the Froude number, the effects of different ventilation rates and buoyancy on the process of bubbles coalescence at two adjacent orifices were investigated. The results show that for horizontal coalescence, the effect of ventilation rate is more pronounced than buoyancy. As the ventilation rate increases or the influence of buoyancy is decreased, the amplitude of internal pressure fluctuation of the bubble decreases and the coalescence time decreases. For vertical coalescence, the effect of buoyancy is more pronounced than ventilation rate. With the influence of buoyancy is decreased, the vertical coalescence time is increased, the internal pressure of the bubble is decreased. The influence of ventilation rate is similar to that of horizontal coalescence.

Numerical Simulation of Oblique Collision of Flier Plate

2013 ◽  
Vol 767 ◽  
pp. 192-195
Author(s):  
Akio Kira ◽  
Hideki Hamashima ◽  
Kazuyuki Hokamoto ◽  
Masahiro Fujita ◽  
Shigeru Itoh
Keyword(s):  
Numerical Simulation ◽  
High Pressure ◽  
High Velocity ◽  
High Explosive ◽  
Collision Process ◽  
Oblique Collision ◽  
New Device ◽  
The Difference ◽  
Metal Jet ◽  
Metal Block

The metal jet that is flowed out by the oblique collision between a metal flier plate and a metal block becomes a high velocity. We have been developing the device that makes a material extremely high pressure by using the metal jet. The flier plate of the previous device had been accelerated by using a high explosive. There were several problems in the collection and analysis of the material that had been made the high pressure. Therefore we thought up the new device of which the flier plate was accelerated by a powder gun. The collision process was examined by a numerical simulation because the collision process of the flier plate of this device differs from that of the previous device. LS-DYNA was used for a numerical simulation and the difference of the collision process was clarified.

Research on Pressure Field of Hydrostatic Center Rest

2013 ◽  
Vol 427-429 ◽  
pp. 262-265
Author(s):  
De Fan Zhou ◽  
Qi Hui Zhou ◽  
Xiu Li Meng ◽  
Xiao Dong Yu ◽  
Zhi Qiang Wang ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Pressure Distribution ◽  
Pressure Field ◽  
Rotation Speed ◽  
Three Dimensional ◽  
Mechanical Deformation ◽  
Cavity Pressure ◽  
Distribution Law

In order to solve the mechanical deformation of the hydrostatic center rest, a numerical simulation concerning pressure field of hydrostatic center rest is studied. CFX of ANSYS has been used to compute three-dimensional pressure field of gap fluid between workpiece and bearing pillow. This research analyzes the influence of rotation speed on the bearing pressure performance according to lubricating theory and computational fluid dynamics, and it has revealed its pressure distribution law of gap oil film. Results indicate that an improved characteristic will be affected by rotation speed easily, and oil cavity pressure increases by gradually with rotation speed enhancing. The reliability of a hydrostatic center rest can be predicted through this method.

Secondary Flow Control on Axial Flow Compressor Cascade Using Vortex Generators

2014 ◽  
Author(s):  
Ahmed M. Diaa ◽  
Mohammed F. El-Dosoky ◽  
Omar E. Abdel-Hafez ◽  
Mahmoud A. Ahmed
Keyword(s):  
Numerical Simulation ◽  
Secondary Flow ◽  
Three Dimensional ◽  
Axial Flow ◽  
Vortex Generator ◽  
Vortex Generators ◽  
Geometrical Parameters ◽  
Compressor Cascade ◽  
Flow Compressor ◽  
Flow Vortex

Axial flow compressors have a limited operation range due to the difficulty controlling the secondary flow. Vortex generators are considered to control the secondary flow losses and consequently enhance the compressor’s performance. In the present work, a numerical simulation of three-dimensional unsteady compressible flow has been developed in order to gain insight into the nature of this flow. Based on the numerical simulation, the effects of vortex generators with variable geometrical parameters and their application inside the cascade are investigated. The predicted flow fields with and without the vortex generators are presented and discussed. For each configuration of vortex generator, the total pressure and loss coefficient are calculated. The predicted velocity and pressure distributions at different locations are compared with the predicted and measured values available in the literatures.

Numerical Simulation of Internal Flow Field in Mixed Flow Fan

2013 ◽  
Vol 860-863 ◽  
pp. 1589-1593
Author(s):  
Yan Zhao Zhai ◽  
Hong Ming Zhang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Velocity Distribution ◽  
Pressure Distribution ◽  
Three Dimensional ◽  
Internal Flow ◽  
Field Structure ◽  
Mixed Flow ◽  
Flow Phenomenon ◽  
Impeller Outlet

The numerical simulation of internal flow field of a mixed-flow fan was carried out on the star-CD platform. Three-dimensional steady turbulent flow is calculated using the standard k-ɛ turbulence model, and the pressure distribution, velocity distribution and other important flow phenomenon inside the fan are obtained. The number of meshes has important influence on the result, meanwhile, fan inlet, impeller, outlet interact with each other. The results of numerical simulation can accurately analyze the fan flow field. The results of numerical simulation can accurately analyze the fan flow field structure, and provide guidance for further optimization and improvement of the fan.

3D-Modelling and Simulation of Physicochemical Transformations in a High-Pressure Turbine (HPT) of an Aircraft Engine

2014 ◽  
Author(s):  
T. H. Nguyen ◽  
F. Garnier
Keyword(s):  
High Pressure ◽  
Large Scale ◽  
Three Dimensional ◽  
Aircraft Engine ◽  
Navier Stokes ◽  
Geometrical Parameters ◽  
High Pressure Turbine ◽  
3D Design ◽  
Complex Interactions ◽  
Fluent Software

In this work, the 3D design of the stator, rotor of a turbine is performed. A one way coupling between a detailed physicochemical box model and multidimensional Navier-Stokes solver (FLUENT software) is used. Various series of three-dimensional calculations including approximately 500,000 elements are carried out to calculate aero-thermodynamics fields for a first stage of high-pressure turbine of the CFM56 aero-engine. The results show that blades of early turbine stages, directly downstream of combustor are subjected to relatively high levels of unsteadiness generated from complex significant three dimensional shear layers. The latter causes the formation of large-scale turbulent. By consequence, the complex interactions between the geometrical parameters, thermodynamical and chemical processes involving aerosol precursor formation in the turbine are analyzed and investigated.

scholarly journals Numerical Simulation of the Intra-Aneurysmal Flow Dynamics

2006 ◽  
Vol 12 (1_suppl) ◽  
pp. 49-52 ◽  
Author(s):  
M. Shojima ◽  
M. Oshima ◽  
K. Takagi ◽  
M. Hayakawa ◽  
K. Katada ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Three Dimensional ◽  
Cerebral Aneurysms ◽  
Computed Tomographic Angiography ◽  
Flow Dynamics ◽  
Patient Specific ◽  
Geometrical Parameters ◽  
Computed Tomographic ◽  
Tomographic Angiography ◽  
Middle Cerebral Artery Aneurysms

Intra-aneurysmal flow dynamics is analyzed qualitatively and quantitatively with numerical simulation technique, and presented for the future clinical application in embolizing cerebral aneurysms. From the volumetric data obtained by three-dimensional computed tomographic angiography, patient-specific vessel models were created for 16 middle cerebral artery aneurysms. Intra-aneurysmal flow dynamics was visualized and analyzed qualitatively, and the geometrical parameters of vessels and aneurysms that affect the intra-aneurysmal flow dynamics were determined quantitatively by correlation analysis. The flow velocity was delayed in the aneurysm cavity, especially at its tip where the rupture usually occurs. The intra-aneurysmal flow dynamics was considerably influenced by the geometrical parameters that are related to the width of the neck and the branching angle of larger branch artery. The intra-aneurysmal flow dynamics is complex, and the numerical flow simulations with patient-specific vascular models seems effective in understanding the flow dynamics and planning the endovascular treatment of cerebral aneurysms.

Formula for Calculating Pressure Distribution of Crude Oil Flowing through 180 Degree Bend

2017 ◽  
Vol 872 ◽  
pp. 209-216
Author(s):  
Xiao Yang Lu ◽  
Lu Lu Wang ◽  
Li Li Huang ◽  
Shao Bo Lu ◽  
Xiao Xiao Wang
Keyword(s):  
Crude Oil ◽  
Internal Pressure ◽  
Pressure Distribution ◽  
Working Condition ◽  
Safety Evaluation ◽  
Maximum Relative Error ◽  
Distribution Law ◽  
Long Distance ◽  
Bend Pipe ◽  
Fluent Software

FLUENT software was used to analyze the distribution of internal pressure P of elbow with the variation of outlet pressure P0, inlet velocity v, fluid density ρ and the degree of curvature k=R/D during the flow of crude oil in 180 degree bend pipe, to establish 135 kinds of working condition of internal pressure P distribution database. According to the distribution law of the pressure of the inner wall of the elbow under different parameters (P0, v, ρ, k), calculation formula of the internal pressure distribution of the pipe is analyzed and fitted by 1stOpt software. Through the numerical simulation results of 11 kinds of working condition of FLUENT, the calculation precision of the formula was verified (Maximum relative error). It provides basis for design of bend pipe and safety evaluation of pipeline in high pressure, high flow rate and long distance petroleum pipeline.

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