摘要: 采用商业软件Fluent对燃油直接喷射入横向气流中的破碎雾化过程进行数值模拟，选用欧拉-欧拉方法中的VOF（volume of fluid）耦合level-set方法模拟气液两相流动.数值模拟了横向气流中燃油直接喷射射流破碎雾化过程及其相应流场信息，分析了流场结构对液柱破碎雾化过程的影响，获得了横向气流中射流破碎点位置以及射流穿透深度，并与试验数据进行了对比.数值计算结果表明：①采用VOF耦合level-set算法能够较好地模拟射流喷入横向气流中燃油破碎雾化过程；②由于反向旋转的涡对的存在，使得液膜和液滴沿着展向（y向）输运，对于液滴的二次雾化起到促进作用；③射流液柱总是在喷嘴下游约8倍直径处开始破碎，且破碎点位置取决于喷嘴几何特性.
摘要: A new turbulent constitutive relation was directly derived from Boussinesq's hypothesis and mixing length theory, and then implemented in the standard k-ε model. The performance of this constitutive relation was validated in zero pressure gradient flat-plate boundary layer flow, fully-developed turbulent channel flow and separated flow in a plane asymmetric diffuser. The investigation demonstrated that, this new constitutive relation gave very accurate results in the former two basic cases and provided significant improvement in prediction of separated and reattachment points in the plane asymmetric diffuser. Separation and reattachment points at x/H=7.5 and 29 were calculated accurately in comparison to experimental results, and the static pressure coefficient of 0.82 was very close to large eddy simulation calculation. These results are very encouraging but further verification and extensive application of the new constitutive relation to other two-equation eddy viscosity model are needed.