中文摘要：

采用k-ε和LES大涡模拟两种湍流模型对斜向射流入水垫塘的流场进行了三维数值模拟研究,得到了射流的流速、涡量、压力等水力特性,并与粒子成像测速仪（PIV）得到的结果进行对比。结果表明,射流入水垫塘后其流态为典型的三维流态,受射流上下游紊流涡的影响,射流轴线、速度及压力分布呈现时空随机性的特征。k-ε湍流模型因对涡的各向同性假设,其计算结果不能反映斜向淹没射流流场结构的随机性特征,而LES大涡模型则可获得斜向淹没射流流场的时空随机性流场结构,如射流轴线、流速矢量分布、涡量场和压力场,准确揭示斜向淹没射流入水垫塘的流场演变过程和消能的剪切、混掺机理,并与PIV测试结果吻合良好。

英文摘要：

A k-ε turbulent model and a large eddy simulation（LES） model were used separately to investigate three-dimensional flows of oblique submerged water jets in a plunge pool. Characteristics of flow velocity, voriticity and pressure were obtained and compared with our particle image velocimetry（PIV） measurements. When a jet nappe was plunging into the pool, the flow in the pool was typically three-dimensional, showing temporal and spatial randomness in the jet trajectory and its velocity and pressure distributions under the action of moving turbulent eddies upstream and downstream of the jet. For such oblique submerged jets, the k-ε turbulent model is unable to describe the randomness of this type due to its assumption of isotropic eddies while LES can produce flow structures with temporal and spatial randomness in the jet trajectory and the fields of velocity, vorticity and pressure. Our LES results agree better with the PIV measurements, revealing the evolution of jet plunging into the pool and its mechanism of energy dissipation.