淹没条件下自激脉冲射流冲蚀试验研究

Experiment research on erosion of self-excited inspired pulsatile jet in submerged conditions

为了对比不同淹没条件下连续射流和低压大流量自激吸气式脉冲射流冲蚀效果,利用自行研制的射流冲蚀系统进行了射流冲蚀石蜡效果试验研究,得到不同淹没水深下射流打击力、吸气量、石蜡冲蚀深度、石蜡冲蚀体积和石蜡冲蚀表面积等.结果表明:在不同淹没水深下,连续射流打击力大于吸气脉冲射流,而吸气脉冲射流打击力又大于不吸气脉冲射流打击力,且随着水深的增大,自吸气与不吸气之间脉冲射流打击力差值越来越小;当淹没水深较小时(≤30 m),由于气体对石蜡剥蚀作用较强,连续射流冲蚀深度小于吸气脉冲射流,而当水深较大时(≥40 m),由于吸气量变小,剥蚀作用减弱,冲蚀深度则相反;在冲蚀面积和体积上,在各种淹没水深下吸气脉冲射流冲蚀效果均好于连续射流,且随着水深的增加,两种射流的冲蚀面积和体积逐渐变小,差值也越来越小.

In order to compare erosion effect of the self-excited inspired pulsatile jet with the continuous one under different submergence conditions,experimental studies of paraffin erosion caused from a jet was carried out by using own developed apparatus.In the experiments,the jet impact power,inspired air capacity,eroded surface depth,volume loss and eroded surface area were obtain under different submerged depths.The experimental results showed that the impact power of the continuous jet is larger than inspiration pulse jet;while the power of the inspired pulsatile jet is higher than that of the jet without inspiration.Moreover,the difference in impact power between the inspired and non-inspired jets steadily gets smaller with increasing submerged depth.When the submerged depth is shallower（30 m or less）,the eroded surface depth of the continuous jet is smaller than the inspired pulsatile jet due to the stronger denudation caused from the air inspired.However,if the submerged depth is deeper（40 m or more）,the eroded surface depth of the continuous jet is larger than the inspired pulsatile jet because of the less air inspired.The eroded surface area and volume loss of the inspired pulsatile jet are less than the continuous jet under various submerged depths.The eroded surface area and volume loss of two kinds of jet become small gradually,and their difference between the two jets also gets closer and closer with increasing submerged depth.