Pubblicazione scientifica

Influence of Water on Collisions of Floating Ice Blocks

FILONE TECNOLOGICO	TEMA
economia circolare e sostenibilità

RIASSUNTO

ABSTRACT

In this paper we describe experimental investigations of ice blocks collisions. Ice blocks of pyramidal and cubical shapes sawn from natural sea ice were used in the in-situ experiments. The accelerations of ice blocks colliding in the air and water environments were recorded by the accelerometer with 1.6 kHz sampling frequency and video. Mathematical models describing the interaction of ice blocks in water environment are formulated and the experimental results are reproduced by numerical simulations. Significant reduction of ice blocks accelerations and ice loads are identified in the experiments on ice blocks collisions in water environment.

INTRODUCTION

Melting of sea ice in the Arctic is anticipated to result in an increase in navigational activity in this region. Correspondingly, the risk of collisions between non ice-class vessels with floating ice may also increase. Such collisions can potentially result in significant damage to ship hulls. Therefore, experienced captains will usually reduce the vessel speed to a minimal value of about 2 knots when they operate in ice covered waters to avoid high speed collisions with floating ice. The presence of water may have a dissipative effect and reduce the contact loads during vessel collisions with floating ice blocks of relatively small sizes, as compared with ice loads during vessel impacts on larger floes. Such damping occurs due to momentum transfer to the water between the ice and vessel hull (Fig. 1a). Similar processes have been studied by Gagnon (2004), and Gagnon and Wang (2012), who performed numerical simulations using the software LS-Dyna to model collisions between a tanker with a bulbous bow (1,700,000 t displacement) and bergy bits with mass of 13000 t.

The presence of water between the ice floes may also influence the damping of surface waves due to the production of water jets between floes as they collide. Figure 1b shows water jets caused by floes interacting under compression during the propagation of swells below drift ice in the Barents Sea in April 2006 (Marchenko et al, 2015).

DATA

Data di pubblicazione: 16/06/2019

AUTORI

MARCHENKO ALEKSEY
MARKOV VLADIMIR
TAYLOR ROCKY

ENTE DI AFFERENZA

UNIV CTR IN SVALBARD
LOMONOSOV MOSCOW STATE UNIV INST MECHANICS
MEMORIAL UNIV NEWFOUNDLAND

RIVISTA

ISOPE International Ocean and Polar Engineering Conference, Honolulu, Hawaii, USA

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