Study On Generational Mechanism And2-D Numerical Flume Model Of Internal Waves

The ocean contains abundant resources, such as mineral, oil-gas and marineproducts...etc.. Along with the rapid development of the global economy, countries areincreasingly concerned about the development of ocean resources. With the increasingdevelopment of ocean resources technology development, marine engineering structures isincreasingly the direction of the large-scale development, but which has becomeincreasingly severe environmental conditions. The internal wave in the ocean is one of themain environment disasters in the development of ocean resources. In recent years, theresearch of the generation mechanism of internal wave and its influence to the structures hasbecome a forward-looking study at home and abroad currently, which has importantacademic significance and practical value.On the basis of reviewing and summarizing the progress of this study in internal wave,the works of numerical simulation of internal waves and its influence to the marine riser inthe paper are presented as follows:(1) From potential flow theory, the mathematical model of internal wave in two-layerdensity-stratified and incompressible ideal fluid is built up. Then the paper gets the linearwave solutions under first-order approximation and the solitary wave solutions and cnoidalwave solutions from nonlinear long internal wave equation-Kdv equation. Based on thismathematical model and finite volume method, the RANS equations closed by employingthe k-ε two-equation turbulence model, a numerical two-dimensional internal wave flume isdeveloped on the platform of FLUENT software in this study with a method of generatinginternal waves based on the improvements of flat slapping piston wave-making technology.Through the analysis towards the characteristic of wave-making system, the paper gets thebest dimensions of the wave-making system with the largest wave-making ability. Byanalyzing the flow field of internal periodic wave and internal solitary wave, thedependence of the environmental parameters, such as the depth ratio of the fluids, thedensity ratio of the fluids is discussed. Comparing with theoretical results and thesimulation results, the correctness of numerical internal wave flume is proved.(2) Based on the established numerical two-dimensional internal wave flume, the paperestablished a three-dimensional numerical model used to study internal waves effect on therigid piles, includes internal periodic wave and internal solitary wave. With a numerical simulation and analysis on the characteristics of the periodic and solitary waves flow fieldand the force on the rigid piles, the feasibility of this numerical internal wave flume is beverified respectively.(3) Taking into account that making stable stratified fluid system quickly is aprerequisite and key in physics internal wave experiments, the stratified fluid productionprocess is preliminary numerically simulated and physics experimented based on this theoryof density current and typical gate-type density current phenomena, providing somereference for the physics internal wave experiments.The simulation results of this paper need to be further improved. So, the author putsforward the future direction of the study, excepting for better achievement.