Experimental Study Of Focusing Wave Action On Spar Platform

AbstractWith the onshore and offshore oil and gas resources depleted, the exploration of oil and gas transfer to deep-sea gradually and various offshore platforms that adapt to the deep ocean environment have been designed recently. For its excellent movement performances and lower construction cost, spar platform has become the first choice for the ocean engineers. In the thesis, in order to provide some basis for the design of deep-sea platform, wave force and mooring force that act on the spar platform by focusing waves are studied under physical model test, then some analysis of the motion character of the platform are made.First, systematic investigations of the focusing wave forces acting on the fixed platform are conducted. By comparing the biggest wave force and wave force spectra among three platforms, how the heave plates and helical strakes affect the force that act on the platform can be gotten:the helical strakes can increase the horizontal force of the platform; heave plates almost affect the horizontal force little; both the heave plates and helical strakes can decrease the vertical force performed on the platforms.Then, on the basis of the focusing waves action on floating platform test, analysis of the platform's motion response and mooring force are conducted, so as to the motion response spectra. The result shows that the helical strakes can weaken the platform's motions of pitch and surge, but it may intensify the floating platform's vertical motion; the heave plates can diminish the platform's vertical motion effectively; when the focusing waves period equals the natural period of the platform, the amplitude of the motion will increase by a few times, and it can last for a long time.Experimental study and numerical simulation are two major ways for scientific research. In the thesis, based on Fluent software, the numerical wave tank is established and a better result is gotten.