Turbulence Numeriacal Simulation On Aerated Flow Of The Culvert Sudden Enlargement Type Behind The Valve In Ship Lock

Over thepast twenty years, China has stepped the rapid development track in waterconservancy construction and comprehensive development and the utilization of riverwater resource. The construction of hydro-junction has engenderedone of the benefits isimproving the navigation conditions. The lock as the main type of navigationstructuresis applied most widely in its mature technology, stable work and convenientoperation.With the construction of many high head dams, the working head of locks arealso greatly increased. At the same time, To improve its applicability, wedesignconstantlythe high head of locks and the super high head appear constantlywhichhas gradually become the development trend of modern lock. But the problemofcavitation in high head lock about culvert shape behind valve is a huge hidden troublewhich has restricted the safe operation of the ship lock, and the cavitation damage is thecommon destruction in the lock about culvert shape behind valve. Now there are twomeasures to improve the conditions of cavitation. The one is to optimize the culvertshape, such as the upper and lower culvert sudden enlargement type behind the valve isa more mature solution. Compared with the flat-top type and top expansion type,it notonly meet the requirements of water conveyance of thehigh head lock, but also greatlyreduce the cavitation problem. But the typeis still exist a range of cavitation region,so itneeds to another corrosion mitigation measures which is adding aeration system cansolve the problem of cavitation.The physical model test is the main measure to study aerated flow of the culverttype behind valve,but the numerical simulation about the aeration almost no oneinvolved. Because aerated condition of the gate lintel is complex and it is difficult tosimulate, we use numerical model as the main research means for studying aeratedflowof the upper and lower culvert sudden enlargement type behind the valve. Regarding thetypical high head lock valve in domestic and combining the relevant theoreticalknowledge with physical model test data, we build a model which is a upper and lowerculvert sudden enlargement type and set the step drop sill and rise sill. And we chooseVOF model and Mixture model in Fluent tosimulate in2D. Finally come to thefollowing four major conclusion:①New culvert sudden enlargement is further optimized type, it have increased thepressure within the corridor. Compared to other lock body, its cavitation zone have obtained good improvement. In this paper, the numerical simulation can verify the effectof reducing cavitation;②When the valve are0.4,0.5,0.6and0.7opening, there are a certain area ofnegative pressure zone which are prone to cavitation at the top of the corridor. When thevalve are0.3and0.4opening, there are little negative pressure between first and secondstep on the drop sill;③When the valve is0.4opening and the speed of aeration approach to18m/s, allof the original gallery roof pressure will become the positive pressure.④The aerated flow follows the regular that the higher of aeration rate, the gasconcentration will be greater, and the negative pressure will be better.