Self-propelled Test And Resistance Numerical Analysis Of Jack-up Platform

With the continuous promotion of China’s Marine power strategy,offshore wind power generation is favored by many countries and developed more and more vigorously.Self-propelled jack-up survey platform is an offshore wind power installation equipment with autonomous navigation capability and free lifting.After completing the scheduled work of the station,it does not need towing and can sail to the next working point independently,which improves the work efficiency.In the design stage of self-propelled jack-up platform,the determination and selection of main engine power is particularly important.At the initial stage of design,in order to determine the power of the main engine of the platform,the navigation resistance of the platform should be measured first,and the power of the main engine of the platform should be further calculated based on the resistance.In this thesis,the combined method of test and CFD numerical calculation is used for analysis.Firstly,the scale scale model of the platform hydrostatic resistance towing test and self-propelled test are carried out to measure the total hydrostatic resistance at different speeds and the power of the main engine at the self-propelled point of the platform.Secondly,CFD numerical calculation method is used to calculate the total hydrostatic resistance of the scale ratio model and the real scale model,and the results are compared and analyzed to calculate the power of the main engine of the platform.Finally,the CFD numerical calculation method is used to calculate the wave resistance increase under the regular wave of the real scale platform,so as to determine the total power of the actual platform.The main contents of the thesis are as follows:(1)The main engine power of the platform is preliminarily estimated by model test.Firstly,the scale ratio of the platform is determined according to the main scale of the target platform and the size of the test pool.The resistance test and self-propelled test scheme are formulated.The total static resistance of the platform model and the power of the main engine at the self-propelled point are measured at different speeds.The total static water resistance of the model is converted to the total static water resistance of the actual platform by using the two-factor resistance conversion method,and the power of the main engine of the platform is preliminarily calculated according to the two tests and empirical formulas.(2)The total static water resistance of the platform is calculated by CFD numerical method.On the basis of the resistance test,the CFD numerical method is used to calculate the hydrostatic resistance of the scale model of the platform,and the effects of different mesh sizes,different turbulence models and different time steps on the resistance results are analyzed.The optimal parameters are selected to obtain good calculation results and efficient calculation efficiency.The results agree well with the experimental values.Further,the numerical calculation of hydrostatic resistance of the real-scale platform is carried out to analyze the ratio of each resistance component in the surrounding waveform and total hydrostatic resistance of the platform during navigation.The calculation results are compared with the binary resistance converted into the actual total hydrostatic resistance of the platform to determine the total engine power of the platform during navigation in still water.(3)Aiming at the resistance performance of platform in wave environment,CFD numerical calculation method is used to simulate the real scale platform under regular wave.The wave drag increase and motion of the platform under different speed and wavelength conditions in the fifth order regular wave were analyzed,and the main engine power required by the platform sailing in the regular wave was determined,which provided a basis for the study of the hydrodynamic performance of such platform.