For a physical model of the approach navigation channel of Three Gorges Project（TGP）, flow patterns around a non-submerged spur dike placed as a mountain in a long rectangular glass flume were experimentally investi...For a physical model of the approach navigation channel of Three Gorges Project（TGP）, flow patterns around a non-submerged spur dike placed as a mountain in a long rectangular glass flume were experimentally investigated with and without ＂sucking-spouting＂ water respectively. Based on rigid lid assumption and Dynamic Smagorinsky Model, all these vortex flows around the spur dike were numerically simulated and analyzed, which probably affect the whole flow field and then probably lead to sedimentations for silt-laden two-phase flows. Meanwhile, silt-laden flows were also investigated experimentally. Both the secondary flow region and the silt sedimentations downstream of the spur dike decrease greatly with ＂sucking-spouting＂ water compared to those ones without ＂sucking-spouting＂ water. The Finite Volume Method （FVM） was used to discretize the governing equations together with a staggered grid system, where the second order difference is employed for the diffusion terms and the source terms while the upwind difference QUICK is used for the convection terms. The computational results are all in fairly good agreement with the experimental data.展开更多
Large eddy simulations were used to model the three-dimensional flows around a non-submerged spur dike. Based on the rigid lid assumption, all these vortex flows around the spur dike, which probably affected the whole...Large eddy simulations were used to model the three-dimensional flows around a non-submerged spur dike. Based on the rigid lid assumption, all these vortex flows around the spur dike, which probably affected the whole flow field, were numerically simulated and analyzed. The largest circulating flow region caused by the spur dike behind it was weak, which would naturally lead to sedimentation for silt-laden twophase flows. Based on the Smagorinsky model, the finite volume method was used to discretize the NavierStokes equations, and the SIMPLEC algorithm was used to solve them. Meanwhile, these flows were investigated experimentally in a 0.5-m wide flume with a dike placed as a barrier. The computational results are in a fairly good agreement with the experimental data.展开更多
基于FLUENT计算流体力学软件及其二次开发功能,采用VOF(Volume of Fluid)多相流模型,在k-ε湍流模型下建立了模拟内波传播的分层数值水槽。设置两层稳定分层,以上下层不同密度差和水深比设置工况,利用平板拍击法造波。在刚盖和自由表面...基于FLUENT计算流体力学软件及其二次开发功能,采用VOF(Volume of Fluid)多相流模型,在k-ε湍流模型下建立了模拟内波传播的分层数值水槽。设置两层稳定分层,以上下层不同密度差和水深比设置工况,利用平板拍击法造波。在刚盖和自由表面两种上边界条件下进行数值模拟并与各自的理论解进行比较,分析了两者之间的异同。研究发现密度差的改变不会明显影响理论解与数值解之间的一致程度;上下两层流体深度差值的改变会明显影响数值计算结果。上层水深很小时,在自由表面假定下水气交界面处出现了较为明显的垂向速度;在两种假定下,数值模拟的水平速度都体现了非线性的影响。而当下层水深很小时,非线性的影响微弱。鉴于在实际海洋中上层水深远小于下层水深,尤其是当计算运动幅值更大的内孤立波时,采用更为真实的自由表面假定更为合理。展开更多
基金Project supported by China Postdoctoral Science Foundation (Grant No. 2004036050) Complemental Fundmental Stduies on Silt-laden flow for Three Gorge Project (Grant No. 95-3-2).
文摘For a physical model of the approach navigation channel of Three Gorges Project（TGP）, flow patterns around a non-submerged spur dike placed as a mountain in a long rectangular glass flume were experimentally investigated with and without ＂sucking-spouting＂ water respectively. Based on rigid lid assumption and Dynamic Smagorinsky Model, all these vortex flows around the spur dike were numerically simulated and analyzed, which probably affect the whole flow field and then probably lead to sedimentations for silt-laden two-phase flows. Meanwhile, silt-laden flows were also investigated experimentally. Both the secondary flow region and the silt sedimentations downstream of the spur dike decrease greatly with ＂sucking-spouting＂ water compared to those ones without ＂sucking-spouting＂ water. The Finite Volume Method （FVM） was used to discretize the governing equations together with a staggered grid system, where the second order difference is employed for the diffusion terms and the source terms while the upwind difference QUICK is used for the convection terms. The computational results are all in fairly good agreement with the experimental data.
基金Supported by China Postdoctoral Science Foundation (No.2004036050) and Open Fund of Nanjing Hydraulic Research Institut(No. Yk90504)
文摘Large eddy simulations were used to model the three-dimensional flows around a non-submerged spur dike. Based on the rigid lid assumption, all these vortex flows around the spur dike, which probably affected the whole flow field, were numerically simulated and analyzed. The largest circulating flow region caused by the spur dike behind it was weak, which would naturally lead to sedimentation for silt-laden twophase flows. Based on the Smagorinsky model, the finite volume method was used to discretize the NavierStokes equations, and the SIMPLEC algorithm was used to solve them. Meanwhile, these flows were investigated experimentally in a 0.5-m wide flume with a dike placed as a barrier. The computational results are in a fairly good agreement with the experimental data.
文摘基于FLUENT计算流体力学软件及其二次开发功能,采用VOF(Volume of Fluid)多相流模型,在k-ε湍流模型下建立了模拟内波传播的分层数值水槽。设置两层稳定分层,以上下层不同密度差和水深比设置工况,利用平板拍击法造波。在刚盖和自由表面两种上边界条件下进行数值模拟并与各自的理论解进行比较,分析了两者之间的异同。研究发现密度差的改变不会明显影响理论解与数值解之间的一致程度;上下两层流体深度差值的改变会明显影响数值计算结果。上层水深很小时,在自由表面假定下水气交界面处出现了较为明显的垂向速度;在两种假定下,数值模拟的水平速度都体现了非线性的影响。而当下层水深很小时,非线性的影响微弱。鉴于在实际海洋中上层水深远小于下层水深,尤其是当计算运动幅值更大的内孤立波时,采用更为真实的自由表面假定更为合理。
