【作者】 陈伟东；

【导师】 邱秀云； 周著； 侯杰；

【作者基本信息】 新疆农业大学 ， 水力学与河流动力学， 2007， 硕士

【摘要】 本文研究了新型净水装置——浑水水力分离清水装置结构对清水流场影响的数值模拟。由于现有数值模拟理论已经较为成熟,数值模拟研究可以不受物理模型和实验条件的限制,既省时省钱,又能给出详细和完整的预测结果。因此本文采用数值模拟来研究装置结构对清水流场的影响。本文采用RNG k -ε紊流模型模拟了与PIV所测相同尺寸装置的清水流场,用PIV所测结果验证数值预测结果,在证明了数模试验的可行性的基础上,通过数值方法研究装置结构对清水流场影响。由数值模拟得出以下结论:(1)装置内存在一绕装置中心旋转的偏心涡旋,漩涡的旋转方向与水流方向同向。在柱体区切向流速呈现出明显的强迫涡特征,即v_θr~n =C,(n<0),在锥体区呈强迫涡和自由涡的组合涡特征。轴向速度分布为两个环流,中心与边壁区域向上流动,中心与边壁之间区域向下流动。径向速度正负相间分布,呈现出装置内部流场的螺旋流特性。(2)增大装置进流量和底孔孔径时流场内各向流速相应增大;增加高度和锥角时流场内各向流速相应减小。同一分流比时,增大装置的比尺,流速值约成正比增加。下悬板的设置使得整个流场的运动速度减弱,中悬板的设置主要减小了切向速度,增大了径向速度,并起到改变径向运动方向的作用,上悬板对流场流速的影响微弱。更多还原

【Abstract】 In this paper effect of structure on a clear water flow field in new water purification device -- Turbid water hydraulic power separation equipment was researched by numerical simulation. Because existing numerical simulation theory is more mature, this is not limited by physical model and experiment condition. The numerical simulation not only saves time and money, but also gives detailed and complete results. So this paper based on the numerical simulation, research the effect of structure on the clear water flow field in equipment.In this paper, RNG k ?εturbulence model was used to simulate flow field of the same size device which had been measured by PIV. The numerical forecasting results agree with the PIV measured results. The simulation has come to the following conclusions:(1)An eccentric centre vortex goes around with the centre of the equipment; the rotation direction is same with the flow direction. Tangential velocity field has the forced vortex characteristics at cylindrical body,vθrn =C,(n<0), forced vortex and free vortex are combined as hybrid eddy at cone. Axial velocity field distributes as two cyclic flows, the direction is upward at the center and side wall, and downward at the other region. Radial velocity distributions are alternate positive and negative, and prove that the clear water flow field in equipment is cylindrical spiral flow field.(2)With the enter flow and bottom diameter of the equipment going up, the velocity will increase. But With height and cone angle increasing, the velocity will decrease. When split ratio of the equipment is same, increasing the scale of the device, the velocity will increase sharply. Setting up underside suspended slab, it helps to reduce the velocity of the flow field. Middle suspended slab reduces the tangential velocity and increases the radial velocity; it also changes the direction of radial velocity. And the effect of underside suspended slab on the flow field is weak.更多还原