湖库双线型密度分布下选择性取水泄出层厚度理论推导及CFD模拟验证

泄出层厚度是湖库选择性取水应用的重要参数之一。本文针对在线形密度下泄出层厚度理论存在应用范围较窄的问题,通过建立以取水口为中心的球坐标体系和伯努利方程,理论推导了在实际更为普遍的双线型密度分布下选择性出流泄出层厚度计算表达式。建立了金盆水库取水构筑物的CFD模型,利用实测水库纵向密度分布模拟了水库在双线型密度分布下的泄出层厚度。将结果与理论计算结果相比较,在距离取水口20m后形成稳定泄出层时两者一致,在20m之内具有相同的变化趋势。与单线型下的泄出层厚度表达式相比,双线型密度分布下的泄出层厚度表达式具有更为广泛的应用范围。

Formula derivation and CFD simulation validation of selective withdrawal layer thickness for bilinear density distribution of lakes and reservoirs

Layer thickness is one of the most important parameters of reservoir selective withdrawal.For the theory of layer thickness under linear density distribution exists the problem of narrow application range,this paper deduced a more prevalent theoretical withdrawal layer thickness formula in practice by using the Bernoulli's equation and building a spherical coordinate system under a bilinear density distribution.CFD model of Jinpen Reservoir water intake structure is built to simulate the withdrawal layer thickness under the bilinear density distribution using the measured longitudinal density distribution.To compare the simulated results and the calculated results,it shows that the comparison of results are consistent in the stable region 20 m away from the water intake while have the same trend within 20 m.Compared with the withdrawal layer thickness formula under single-linear density distribution,the withdrawal layer thickness formula under a bilinear density distribution has a wider range of applications.