Parameters deduced from the pressuremeter test

2002 ◽  
Vol 39 (6) ◽  
pp. 1333-1340 ◽  
Author(s):  
A Fawaz ◽  
M Boulon ◽  
E Flavigny

This paper presents a study of the pressuremeter test and the results that can be obtained from this test. Hostun's fine sand was chosen as the material upon which to perform the experimental study of the pressuremeter. Numerical simulations of the pressuremeter tests have been made with the commercially available PLAXIS software. The numerical results have been compared with the experimental ones. The variation of the parameters resulting from an applied surcharge was studied experimentally and numerically. Finally, the relationship between the magnitude of the deformation and the pressuremeter modulus was analyzed.Key words: sand, pressuremeter, triaxial, pressure, modulus, deformation, numerical simulation.

Author(s):  
Mojtaba Fardi ◽  
Yasir Khan

The main aim of this paper is to propose a kernel-based method for solving the problem of squeezing Cu–Water nanofluid flow between parallel disks. Our method is based on Gaussian Hilbert–Schmidt SVD (HS-SVD), which gives an alternate basis for the data-dependent subspace of “native” Hilbert space without ever forming kernel matrix. The well-conditioning linear system is one of the critical advantages of using the alternate basis obtained from HS-SVD. Numerical simulations are performed to illustrate the efficiency and applicability of the proposed method in the sense of accuracy. Numerical results obtained by the proposed method are assessed by comparing available results in references. The results demonstrate that the proposed method can be recommended as a good option to study the squeezing nanofluid flow in engineering problems.


2012 ◽  
Vol 161 ◽  
pp. 53-57 ◽  
Author(s):  
He Li Peng ◽  
Ming Zhe Li ◽  
Peng Xiao Feng

Flexible DCSF technology was put forward, and its forming character was described. The flexible DCSF machine was developed and related stretching experiment were carried out. The experimental photos show the DCSF technology is feasible and the DCSF machine is practicable. The FE model of flexible DCSF was set up, and extensive numerical simulations for spherical parts, saddle parts and S-type parts were carried out by Abaqus. The numerical results show that the longer the transitional length is, the more homogeneous the stretching strain and the thickness become. The smaller the friction coefficient is, the more homogeneous the stretching strain and the thickness become. The larger the clamp number is, the better the fit degree becomes. This work may provide useful guidance on the flexible DCSF process.


2015 ◽  
Vol 28 (24) ◽  
pp. 9501-9506 ◽  
Author(s):  
Liguang Wu ◽  
Wei Tian ◽  
Qingyuan Liu ◽  
Jian Cao ◽  
John A. Knaff

Abstract Tropical cyclone (TC) size, usually measured with the radius of gale force wind (34 kt or 17 m s−1), is an important parameter for estimating TC risks such as wind damage, rainfall distribution, and storm surge. Previous studies have reported that there is a very weak relationship between TC size and TC intensity. A close examination presented here using satellite-based wind analyses suggests that the relationship between TC size and intensity is nonlinear. TC size generally increases with increasing TC maximum sustained wind before a maximum of 2.50° latitude at an intensity of 103 kt or 53.0 m s−1 and then slowly decreases as the TC intensity further increases. The observed relationship between TC size and intensity is compared to the relationships produced by an 11-yr seasonal numerical simulation of TC activity. The numerical simulations were able to produce neither the observed maximum sustained winds nor the observed nonlinear relationship between TC size and intensity. This finding suggests that TC size cannot reasonably be simulated with 9-km horizontal resolution and increased resolution is needed to study TC size variations using numerical simulations.


2011 ◽  
Vol 130-134 ◽  
pp. 1568-1572
Author(s):  
Hui Wang ◽  
Jie Gang Mu ◽  
Miao Yin Su ◽  
Shui Hua Zheng ◽  
Jin Jing Zhao ◽  
...  

The paper studies the relationship between axial force and breadth of back blade by numerical simulation and experiment. On the basis of the RNG k-ε turbulence model and technology of compact local grids and regional computing, three dimensional numerical simulations to 100HZ165-250 centrifugal pump with various breadths were carried out. Through comparing and analyzing of the flow field, it can be seen that the axial force reduces with the increase of the back blade breadth. After that, the simulation results were verified by the experimental data got from different test devices, and it shows that the conclusions are reliable.


2014 ◽  
Vol 532 ◽  
pp. 447-451
Author(s):  
Li Sheng Zhang ◽  
Jin Jiang ◽  
Zhi Huai Xiao ◽  
Yan Hui Li

In this paper, the relationship between impeller design parameters and performance of a partial emission pump is studied by numerical simulation. Nine straight radial impellers with different blade ratio γ (short blade length to long blade length ratio, γ=50%, 70% and 90%) and different front inclination angle β (β=8, 12 and 16 degree) were designed, while the rest geometric parameters of the pump were kept unchanged. All the numerical simulations were carried out by using the commercial software FLUENT V12.1 based on the Realizable k-ε turbulent model. The results showed that with increasing of front inclination angle, the capacity-head curve drops, the maximum head all appears at blade ratio γ=90%. The static pressure increases with increasing radius. A separation bubble can be observed at the outlet of diffuser tube.


Author(s):  
Lars Andersson ◽  
Per Andersson ◽  
Jan Lundwall ◽  
Jan Sundqvist ◽  
Pascal Veber

This paper presents a comparison between experimental results and numerical simulations of a reactor pressure vessel internals response due to a rapid depressurization associated to a pipe break. The experiment is designed to fulfil conditions relative to a Pressurised Water Reactor (PWR). The numerical simulation is performed with the computer program package ADINA. The calculations are performed both with and without Fluid Structure Interaction (FSI) effects. It is shown that FSI effects are very important for this problem. The comparison between experimental and numerical results is performed for local pressure in the water and displacements and strains in the reactor vessel and internals. Our experience is that good numerical results can be achieved for this type of loading for all compared quantities. Note that the experiment was set up to show the importance of FSI-phenomena, the effect of this could then be stronger in the experiment compared to a “real” case.


2013 ◽  
Vol 631-632 ◽  
pp. 1001-1005
Author(s):  
Shao Bo Wang ◽  
Shen Guang Fang ◽  
Li Qin Cui

Turbulent Prandtl number used in numerical simulation has effect on exact prediction of velocity and heat transferring with two dimensional buoyant mathematical models. Various Prandtl number values advised by experiments are used to study its effect on numerical results approaching to real ones with model under axisymmetric coordinate. It shows that axial velocities can’t be affected by using various values of of Prandtl number in numerical simulations and can be predicted well. However, it affects the exact prediction of axial concentration to extent, and a smaller value of Prandtl number tends to forecast a smaller axial concentration than real one, and vice versa. A reasonable range of turbulent Prandtl number for various Reynold numbers was suggested.


2011 ◽  
Vol 308-310 ◽  
pp. 2340-2344 ◽  
Author(s):  
Xiao Yu Wang ◽  
Zong Xi Cai ◽  
Peng Cheng Su ◽  
Hai Feng Zhao ◽  
Yi Lan Kang

In order to determine the normal force acting on the TBM disc cutter, a 3-D FEM model is established to simulate the cutting process, with the failure effect of the rock. Afterwards, by using this model, a series of numerical simulations are performed. Based on the numerical simulation results, via modifying Evans formula, an improved formula is given. The modified formula indicates the relationship between the normal force acting on a single disc cutter and the penetration depth, and contains the influence of formation stress and wear.


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