Study of algorithms of new slender ship theory of wave resistance

In this paper, Noblesse's New Slender-Ship Wave-Making Theory was investigated numerically. Detailed expressions of zeroth and lst order wave resistance have been derived and calculation programs have also been compiled. In the single and double integral terms of Green function, the kernel function of wave resistance expression, special function expansion method and Chebyshev polynomials approach have been adopted respectively, which greatly simplify the calculation and increase the convergence speed.

On the development of ice-water-structure interaction

Ice-water-structure interaction (IWSI) is a novel extension of the fluid-structure interaction (FSI), which is significant fordesign and operating of polar ship and offshore structures. It involves multi-media and multi-interfaces and thus is quite complicated tosolve, no matter from mathematical or mechanical perspectives. Although IWSI is complex and still very new, researchers try todevelop various methods to deal with it and relevant literature starts to bloom. This paper aims to provide concise descriptions oftypical analytical numerical and experimental methods to solve IWSI, together with a review of their major applications to date. Lastly,we succinctly highlight some development tendencies and some pieces of work to be investigated for each method.

Joint Characteristics and Corrosion Properties of Bypass-Current Double-Sided Arc-Welded Aluminum 6061 Alloy with Al–Si Filler Metal

Sheets of aluminum 6061 alloy were welded using bypass-current double-sided arc welding with Al-Si filler wire to investigate the effect of Al-Si intermetallic compounds on the microstructure, microhardness and corrosion behavior of weld joint. Experimental results indicated that the Al4.5FeSi phase in the topside of the weld joint was finer than that in the backside and newly formed phase of Al0.5Fe3Si0.5 was observed in the backside. The formation of reinforcing phases of Al-Fe-Si in the weld improved the microhardness of the weld by about 18%. The corrosion resistance of the weld zone was greater than that of the base metal, while the corrosion current displayed opposite, and the corrosion resistance of the weld region was better than that of the base metal.

Comparative Study of Bypass-Current MIG Welded–Brazed Aluminum/Galvanized Steel and Aluminum/Stainless Steel

A bypass-current metal inert-gas welding-brazing technology has been developed to join aluminum/galvanized steel and aluminum/stainless steel. Microstructure, intermetallic compounds and hardness distribution of the joints were studied by optical microscopy, scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction analysis and microhardness tests. Comparative study on both types of joints was carried out. During aluminum to galvanized steel assembling, finer seam was obtained under a more stable process. A uniform interfacial reaction layer with a thickness of 2-4 μm was formed. During aluminum to stainless steel assembling, an uneven interfacial reaction layer with a thickness of 5-45μm was formed. Intermetallic compounds at the interface of aluminum/galvanized steel were identified as Fe-Al- Si-Zn complex phases, while Fe-Al-Cr-Ni complex phases were found at the aluminum/stainless steel interface. Microhardness of interfacial layer increases rapidly within reaction layer due to possible brittle intermetallic compounds.