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采用CFD数值模拟技术,结合κ-ε湍流模型,计算了拦污栅栅条不同截面形式对拦污栅局部水头损失的影响,并将数值模拟结果与拦污栅水头损失经验公式计算结果进行对比,分析了不同截面形式拦污栅的过流流动特性。结果表明,数值计算的局部水头损失与经验公式计算值吻合良好,其中截面形状为圆形的拦污栅水头损失最小,栅后形成的流速梯度较小,沿着水流流向水流过渡最平缓;截面形状为正方形的拦污栅水头损失最大,水流流过栅后会形成较大的漩涡,栅后流速过渡比较急促,紊动作用较强;水流距离拦污栅越远,水流受栅条的影响越小,直至恢复到与拦污栅上游相同的流态,流线逐渐趋于平行。
Using CFD numerical simulation and κ-ε turbulence model, the influence of different cross-section of trash raster fence on the local head loss of trash rack was calculated. The numerical simulation results were compared with the empirical formula of trash rack head loss , The over-flow characteristics of trash rack with different cross-section are analyzed. The results show that the numerical calculation of local head loss is in good agreement with the empirical formula. The trapezoidal cross section has the smallest head loss, the smaller flow gradient behind the gate and the smoothest transition along the flow direction. The cross section The trapezoid head with the square shape has the largest loss, the water flow will form a larger whirlpool after passing through the grid, the transition of the flow velocity will be more rapid after the grid, and the turbulence is stronger; the farther the water flow is from the trash rack, the water flow will be affected by the grid The smaller the flow path is to become parallel, until it is restored to the same flow path upstream of the trash rack.