Investigation of influence of tunneling on existing building and tunnel: model tests and numerical simulations

2016 ◽  
Vol 11 (3) ◽  
pp. 679-692 ◽  
Author(s):  
Hossain Md. Shahin ◽  
Teruo Nakai ◽  
Kenji Ishii ◽  
Toshikazu Iwata ◽  
Shou Kuroi
Keyword(s):  
Numerical Simulations ◽  
Model Tests ◽  
Existing Building ◽  
Tunnel Model

Motions of a 5 MW floating VAWT evaluated by numerical simulations and model tests

2017 ◽  
Vol 144 ◽  
pp. 21-34 ◽  
Author(s):  
Liqin Liu ◽  
Ying Guo ◽  
Haixiang Zhao ◽  
Yougang Tang
Keyword(s):  
Numerical Simulations ◽  
Model Tests

Numerical vs. Experimental Predictions of Yaw Motion of Single Point Moored Vessel

2005 ◽  
Author(s):  
Mathieu Brotons ◽  
Philippe Jean
Keyword(s):  
Numerical Simulation ◽  
Differential Equations ◽  
Numerical Simulations ◽  
Time Domain ◽  
Model Tests ◽  
Linear Differential Equations ◽  
Integration Scheme ◽  
Engineering Model ◽  
Non Linear ◽  
Linear Differential

The accurate prediction of SPM vessel yaw motion is important to its mooring system design. Inconsistencies have been observed between the numerical and model test predictions of offloading responses. In some cases, the numerical simulation predicted unstable yaw behavior of the vessel (fishtailing) while the model tests did not show such instability. This discrepancy between experiment and theory casts doubt as to whether the numerical simulation predicts correctly the vessel yaw motion. The work presented in this paper investigates the following two hypotheses to possibly explain the non-expected fishtailing in the numerical simulations: The mooring software may not accurately integrate non-linear differential equations that describe the yaw motion of the SPM vessel. Some damping terms may be under-estimated in the software (user input issue). To validate the integration scheme of the system of non-linear differential equations as implemented in the mooring software, a stability analysis has been conducted on a shuttle tanker moored to a West Africa deep water buoy. Variations of parameters like the hawser length, its axial stiffness and the vessel’s drag coefficients have been studied to explore their impacts on the vessel yaw stability. The approach is to identify without performing any time domain simulations, the domains of stability by linearizing the differential equations of SPM vessel’s yaw motion around its equilibrium point. The validity of the developed approach is then confirmed by performing time domain simulations of the same case. The second conjecture which may explain the non-expected fishtailing in numerical simulations was that some damping terms may be under-estimated. A semi empirical formula for the drag moment can be derived from rotation tests and comparisons were performed with the engineering model implemented in the mooring analysis software. The results show that by calibrating this damping term with the one derived from the experiments, the numerical simulations would match the stable yaw motion behavior as predicted during model tests. Following the above findings, a tool has been developed to fit the yaw drag moment engineering model based on experimental measurements, for any case of mooring analysis.

Current Drag From Tow and Wind Tunnel Tests of a FLNG Hull

2016 ◽  
Author(s):  
Zhenjia (Jerry) Huang ◽  
Jang Kim ◽  
Hyunchul Jang ◽  
Scott T. Slocum
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Model Test ◽  
Cfd Simulation ◽  
Wind Tunnel Test ◽  
Model Tests ◽  
Additional Contribution ◽  
Wind Tunnel Model ◽  
Tunnel Model ◽  
Current Drag

In this paper, the current drag of a barge-shaped floating liquefied natural gas (FLNG) vessel was studied. Three model tests were performed — a wind tunnel model test, a submerged double-body tow test and a surface tow test. Computational fluid dynamics (CFD) simulations were carried out to gain further insights into the test results. During testing, the tow speed was kept low to avoid surface waves. When the current heading was around the beam current direction, the transverse drag coefficient measured from the wind tunnel test was significantly lower than those of the submerged tow and surface tow tests. The submerged tow and the surface tow provided similar drag coefficients. Results presented in this paper indicated that the difference between the wind tunnel test and the tow tests was caused by the wind tunnel boundary layer effect on the incoming wind profile and formation of a recirculation zone on the upstream side of the model, with a possible additional contribution from the wind tunnel floor constraint on the flow in the wake. Such effects are not accounted for with the simple corrections based on flow velocity reduction in the wind tunnel boundary layer. When conducting future wind tunnel model tests for barge-shaped FLNG hulls, one should consider the potential under-measurement of the transverse drag. In this paper, details of the FLNG model, test setup, test quality assurance (QA), measurement and CFD simulation results are presented, as well as discussions and recommendations for model testing.

scholarly journals Effects of combustion parameters on antiexplosion performance: model tests and numerical simulations

2020 ◽  
Vol 22 (3) ◽  
pp. 594-610
Author(s):  
Xianglian Xu ◽  
Mingxin Bai ◽  
Hongxing Yang ◽  
Meng Xiong ◽  
Wenqiang Zhu ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Model Tests ◽  
Performance Model

scholarly journals STUDIES ON THERMAL DIFFUSION AND VERIFICATION OF THE THIRD NUCLEAR POWER PLANT IN TAIWAN

1986 ◽  
Vol 1 (20) ◽  
pp. 198
Author(s):  
K.C. Tang ◽  
M.T. Tsai ◽  
Y.R. Hwang ◽  
H.H. Hwung
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Numerical Simulations ◽  
Thermal Diffusion ◽  
Nuclear Power ◽  
Field Measurements ◽  
Hydraulic Model ◽  
Model Tests ◽  
The Third ◽  
Made In

In general, hydraulic model tests and numerical simulations can be used for securing enough informations in order to assess the environmental impact by thermal discharge after the power plant operation. However, the numerical simulations should be verified by the consequence of hydraulic model tests or the field data. Then, the numerical model can be used as a prediction model to foresee the nature of thermal diffusion when the additional generators will be operated. The third nuclear power plant in Taiwan has been constructed in 1984. In order to protect the abundant corals which distributed on the rocky bottom around this power plant, a complete studies on thermal diffusion have been performed, accordingly, a verification with field measurements were also made in this paper.

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