Research On Resistance Performance And Structure Of Manned Pressure Hull Of The Third-generation Full-ocean-depth Manned Submersible

Developed countries headed by USA and Japan are challenging11000m abyss of sea. So far,American manned submersibles, Trieste and Deepsea Challenger, have successfully reached11000m seabed. And American companies, DOER Marine, Triton and Hawkes OceanTechnologies, are trying to develop and manufacture their full-ocean-depth manned submersibles.According to the report of Japan’s Yomiuri Shimbun on January7,2014, the Japanese Ministryof Education has set Shinkai12000submersible as Japan’s state-level basic technological projectgiven the highest priority in May,2013, and Shinkai12000’s sea trial was arranged in2023. Onthe other hand, currently, the second-generation deep-sea manned submersible needs to beimproved urgently due to its slow diving speed. Under such background, the third-generationfull-ocean-depth manned submersible (TFMS), which dives much faster, emerged.In this thesis, a summary of technological concepts of TFMS is given first, which set up atechnological frame for TFMS. Based on that, the thesis focuses on two key technologies ofTFMS—that is, submersible’s resistance performance and structural design of new mannedpressure hull. For submersible’s resistance performance, the resistance performance ofDeepsearch submersible is analyzed based on the previous studies on Deepsea Challenger andDeepflight Chanllenge. Firstly, Deepsearch submersible’s shape is parameterized. Then,approximate formula is set up which can calculate Deepsearch’s resistance and volume, usingOptimal Latin hypercube design method, response surface model and CFD method. Finally, thesubmersible’s shape is optimized using genetic algorithm and a series of optimized designs ispresented.According to the analysis of Deepsearch’s resistance performance, it is concluded thatreducing maximum diameter and increasing length-diameter ratio is the most effective way toreduce resistance. To reduce maximum diameter of submersible, radial size of manned pressurehull needs to be reduced. Double intersecting spheres pressure hull may be a good choice forTFMS, since it has small radial size and big length-diameter ratio.For the new design of manned pressure hull, this thesis firstly gives a preliminary structuraldesign of full-ocean-depth spherical pressure hull based on FEM calculation and the ultimatestrength formula proposed by Pan Binbin and his co-workers. Effect of initial imperfection onspherical pressure hull’s ultimate strength is also discussed. Then, based on structural designs fora spherical pressure hull of800mm radius and a spherical pressure of650mm radius, a reasonable structural design of double intersecting spheres is provided. Finally, the relationshipbetween the parameters of connecting channel and the ultimate strength of the whole pressurehull and the relationship between parameters of connecting channel and the stress level of highstress areas of connecting channel is discussed.The present research on TFMS’s resistance performance and structural design of mannedpressure hull will provide a basis for more in-depth study and development of TFMS.