Session K.pdf - Clarkson University

consist in indemnification of the increased durability by smaller thickness of an icecover. It is possible to allocate the part of ice resistance connected to destruction of iceexperimentally. For a nature, resistance of destruction is recalculated on the dependencesreceived with use of the theory of similarity and dimensions [2, 5]:R4 3 −1 3 3 2= ; υ n = λ υm; hn= λ λЕ = λ hm,n 3 md λ R dwhere λЕ– the relation of modules of elasticity of natural and thin fresh-water ice.For check of an opportunity of such modeling in ice pool tests of a scale series of the icebreaker of project É-47, the ice breaker of the project 1105, the international model ofR-class and others have been carried out. Scales of models varied from 1:13,5 till 1:50.Results of tests have shown satisfactory convergence with the natural data. Recalculationof resistance for a scale series of ice breaker R-47 has not revealed significant scaleeffect. Besides satisfactory results turned out at essential reduction in labour input andcost of tests. Visual supervision, the analysis of a photo and filmings have shown, thatthe geometrical sizes of fragments of ice and their form, and also process of interactionfor courts with traditional forms is close to observable in natural conditions. This way ofmodeling is not opposed more strict, based on selection of model of an ice cover adequatematerial. However it allows to expand volume of researches with use of the inexpensiveequipment, has simple technology, and is, in essence, unique at test seminaturalmodels in open reservoirs. The resulted dependences can be used for recalculation of iceresistance from the prototype. But this way is not ideal. In particular, the parity betweengravities and elasticity of an ice plate is not kept, energy of local destruction of an edgeof ice is unsatisfactorily modeled at contortion.Searches of models of an ice cover more full satisfying conditions of similarity and possessinghigh adaptability to manufacture have led to creation of composite constructionof ice model (1071515 and 1559593).Modeling ice represents multi-row layer of polythene granules of high pressure (granularpolyethelene ice – GP-ice), in regular intervals distributed on water surface and exposedto frost on a part of the thickness (fig. 1).Fig. 1. Composite model of an ice cover:1 – particles of polythene; 2 – natural fresh-water ice; 3 – waterThe surface of water in the pool with the help of the mechanized dosing out device becomescovered by a layer of the granulated polythene of a high pressure, and then is ex-373