水射流割縫造網技術是增加煤層透氣性、提高煤層氣開采效率的有效途徑。與普通水射流相比，空化射流因空泡潰滅產生的強大沖擊具有更高的破巖效率。為進一步增強空化射流破煤巖能力以促進煤層氣開發，分別利用中心體和高低壓射流產生繞流空化與剪切空化來提升空化效應，提出了新型的非淹沒雙空化射流?；诙嘞嗔鱉ixture模型和RNG  k-ε輸運方程，對不同嵌入深度與不同形狀中心體下的流場進行了數值模擬，分析了射流流場氣含率和軸線速度分布特征，得到了雙空化射流中心體結構的最優參數。隨后，結合群泡潰滅動力學理論，將最優中心體結構下雙空化射流的壓力與氣含率作為邊界條件，利用多物質流固耦合算法與ALE（任意拉格朗日-歐拉）算法對雙空化射流沖擊煤巖進行了耦合求解。探究了煤巖破碎過程中流體與固體的相互作用特征及煤巖的破碎過程，并對比分析了雙空化射流與普通水射流的破巖效果。研究結果表明，在中心體嵌入深度l=0.5 mm時，雙空化射流的含氣區域最大，在距中心體末端10 mm位置處氣含率可達0.9，空化效果最好；中心體AB端均為90°錐角時，雙空化射流的集束性與空化效果同時最優。由雙空化射流破煤巖的流固耦合結果可知，其對煤巖的沖蝕深度和孔徑明顯大于普通射流，在100 μs時雙空化射流對煤巖的沖蝕深度和孔徑分別為普通水射流的2.4倍和1.3倍。隨著時間的延長，沖蝕孔徑不再明顯增加，而沖蝕深度不斷增大，且與沖蝕時間呈線性關系。研究結果證明雙空化射流具有更強的空化效果，破煤巖能力更強，因而可在一定程度上促進煤層氣的開采。

Water jet slotting technology is an effective way to form a crack network in the coal seam and increase the permeability,resulting in the improvement of the efficiency of coalbed methane exploitation. Compared with a conventional water jet,a cavitating jet has higher rock breaking efficiency because of the powerful impact caused by the collapse of numerous bubbles. In order to further enhance the coal rock breaking ability of cavitating jet to promote coalbed methane development,a centralbody and high and low pressure jets were used to produce flowaround cavitation and shear cavitation at the same time. Thus,a new type of non submerged dual cavitating jet which has enhanced cavitating effect was produced. Based on the multiphase flow mixture model and the RNG k-ε transport equation,the flow field under different embedded depths and different shapes of the centralbody was numerically simulated,and the optimal parameters were obtained by analyzing the vapor volume fraction and the velocity distribution at the axis of the jet. Then,based on the theory of group bubble collapse dynamics,the pressure and vapor ratio of the dual cavitating jet with the optimal structure of central body were taken as boundary conditions,and the coupled solution of dual cavitating jet impacting coalrock was carried out by combining the multimaterial fluid structure interaction algorithm and the ALE (Arbitrary Lagrange Euler) algorithm. The interaction characteristics of fluid and solid in the process of crushing coal rock were studied,and the rockbreaking effect of a conventional water jet was used for comparison. The research results show that when the depth of the central body l=0.5 mm,the vaporcontaining area of the dual cavitating jet is the largest,and the cavitation effect is the best with the vapor volume fraction reaching 0.9 at the position 10 mm away from the end of the central body. The dual cavitating jet has the best clustering property and cavitation effect when both the AB ends of the central body have a cone angle of 90°. From the fluidsolid interaction results of the dual cavitating jet breaking coalrock,it was found that the erosion pit depth and diameter of the dual cavitating jet on coal rock are 2.4 and 1.3 times greater than those of a conventional water jet at 100 μs. With the increase of time,the erosion pit diameter no longer increases significantly,but the depth continues increasing linearly as a function of the erosion time. It can be concluded that a dual cavitating jet has a stronger cavitating effect and a greater coal rock breaking ability,and thus it could promote the exploitation of coalbed methane at a certain extent.