学术报告：Modelling the Effects of Fluid Compressibility during Violent Wave Impacts on Structures

       报  告  人：Ling Qian, Reader in Computational Fluid Dynamics

 

                       Director of Centre for Mathematical Modelling and Flow Analysis,

 

                       School of Computing, Mathematics and Digital Technology,

  

                       Manchester Metropolitan University, UK

 

       报告时间：2016年3月18日上午9:30

 

       报告地点：严恺馆702

 

       主办单位：港口海岸与近海工程学院

 

       报告摘要：

 

       Violent wave impacts on coastal, offshore and ocean structures involve complex flow processes of free surface break-up and fragmentation, flow turbulence and air entrainment. An accurate prediction of the flow and the resulting wave loading on structures is therefore extremely challenging but of great importance for analysis of the reliability of existing structures and design of new structures such as LNG tanks, FPSO platforms, emerging wave and tidal energy converters as well as offshore fixed and floating wind turbine support structures. 

 

       To model free surface flows, traditionally the flow is assumed incompressible.  However, it has been revealed that the presence of air in water due to the entrapment of large air pockets or entrainment of small air bubbles during a violent wave impact event will alter the acoustic property of the underlying fluid and the effects of fluid compressibility may become important. Examples include the air cushioning effects during water entry of flat-bottomed structures and oscillatory nature of wave loading on coastal and offshore structures due to wave impacts by certain type of breakers.

 

        To consider these effects and to predict the impact forces accurately and reliably a compressible multi-phase flow solver should be applied at least locally at the region of the impact. In this talk, the recent work at Manchester Metropolitan University, UK in developing and applying compressible multi-phase flow solver for free surface flow problems involving violent wave impact will be discussed.  Several examples, including the simulation of water entry of a flat plate, violent sloshing of liquid in a tank and wave slamming on a flap type wave energy converter, will be considered.