Liu Z.,State Key Laboratory of Ocean Engineering |
Lin Z.,State Key Laboratory of Ocean Engineering |
Liao S.,State Key Laboratory of Ocean Engineering |
Liao S.,Shanghai JiaoTong University |
Liao S.,King Abdulaziz University
Wave Motion | Year: 2014
The nonlinear interaction between the unidirectional bichromatic wave-train and exponentially sheared current in water of an infinite depth is investigated. The model is based on the vorticity transport equation and the exact free surface conditions, without any assumptions for the existence of small physical parameters. Earlier works of the wave-current interaction were mainly restricted to either current acted on the monochromatic wave or irregular waves limited to irrotational current. Different from these previous works, no constraint is made in our model for amplitudes of the primary wave, and the current owns an exponential type profile along the vertical line. To ensure that the effect of vorticity on the phase velocity is consistent with earlier derivation, the case of a small amplitude wave traveling on the exponentially sheared current is examined firstly. Then the effect of nonlinearity on the phase velocity of primary waves in a bichromatic wave-train is considered. Accurate high-order approximations of the phase velocity are obtained under consideration of both the nonlinear wave self-self and mutual interactions. Finally, the combined effect of vorticity and nonlinearity on the phase velocity is investigated through the case of a bichromatic wave-train propagating on an exponentially sheared current. It is found that the characteristic current slope determines the effect of vorticity on the phase velocity caused by nonlinear wave self-self and mutual interactions, and the surface current strength may amplify/reduce this effect. © 2014 Elsevier B.V.
Yao B.,State Key Laboratory of Ocean Engineering |
Yao B.,Shanghai JiaoTong University |
Wu G.,University College London
International Journal of Heat and Mass Transfer | Year: 2015
The boundary layer flow over a shrinking sheet into a slot with power-law velocity is analytically studied by a newly developed technique namely homotopy analysis method (HAM). The present work provides analytically new solution branch in different solution areas with the aid of an introduced transformation. The analytical results show that quite complicated behaviors controlled by mass transfer parameters f0 exist, including the known algebraically decaying solution, additional dual solutions and unique solution, which greatly differ from the continuously stretching surface problem. The new analytical solution branch enriches the solution family of the boundary layer flow over a shrinking sheet into a slot with power-law velocity, and helps to understand it deeply. © 2015 Elsevier Ltd. All rights reserved.
Guo J.-H.,Shanghai JiaoTong University |
Lu C.-J.,Shanghai JiaoTong University |
Lu C.-J.,State Key Laboratory of Ocean Engineering |
Chen Y.,Shanghai JiaoTong University |
Cao J.-Y.,Shanghai JiaoTong University
Journal of Hydrodynamics | Year: 2010
Based on a suite of CFD code, a homogeneous, multiphase, Reynolds averaged Navier-Stokes solver coupled with a transport cavitation model and a local linear low-Reynolds-number k-ε turbulence model closure was used to simulate the ventilated cavitating flows around a wedge hydrofoil. The gas leakage regimes at the aft of ventilated cavities were investigated. Three gas leakage regimes were observed, and corresponding to each regime, ventilated cavities exhibited a different morphology. The numerical results were compared to corresponding experimental results in qualitative manner. It was found that the general characteristics of the gas leakage regimes and cavity morphology were very reasonably predicted. © 2010 Publishing House for Journal of Hydrodynamics.
Liao S.J.,State Key Laboratory of Ocean Engineering |
Liao S.J.,Shanghai JiaoTong University |
Liao S.J.,King Abdulaziz University |
Wang P.F.,CAS Institute of Atmospheric Physics
Science China: Physics, Mechanics and Astronomy | Year: 2014
Using 1200 CPUs of the National Supercomputer TH-A1 and a parallel integral algorithm based on the 3500th-order Taylor expansion and the 4180-digit multiple precision data, we have done a reliable simulation of chaotic solution of Lorenz equation in a rather long interval 0 ≤ t ≤ 10000 LTU (Lorenz time unit). Such a kind of mathematically reliable chaotic simulation has never been reported. It provides us a numerical benchmark for mathematically reliable long-term prediction of chaos. Besides, it also proposes a safe method for mathematically reliable simulations of chaos in a finite but long enough interval. In addition, our very fine simulations suggest that such a kind of mathematically reliable long-term prediction of chaotic solution might have no physical meanings, because the inherent physical micro-level uncertainty due to thermal fluctuation might quickly transfer into macroscopic uncertainty so that trajectories for a long enough time would be essentially uncertain in physics. © Science China Press and Springer-Verlag Berlin Heidelberg 2014.
Hu X.,Shanghai JiaoTong University |
Chen J.-J.,Shanghai JiaoTong University |
Chen J.-J.,State Key Laboratory of Ocean Engineering
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2015
An FEM model for a single pile embedded in a saturated seabed is proposed to study the interactive behavior between pile and seabed soil. Fluid-soil coupling and contact behavior on interface is considered, and the quasi-static method is adopted to simulate the crested short wave-induced load on seabed surface. Based on the numerical results, responses of pore water pressure and stress seabed soils under the wave load are investigated, and the deformation and internal force of the single pile are discussed. Two different methods to simulate the pile-soil interface are discussed with a comparison to the greenfield seabed model. The results show that the pore water pressure increases obviously near the bottom of pile, and the lateral displacement of pile is mainly affected by soil. Moreover, the pore water pressure and stress are overestimated by the pile-soil coupled model, and the stress concentration at bottom of pile is more obvious than that by the pile-soil contact model. ©, 2015, Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering. All right reserved.