湍流模型对轴流泵全工况计算精度的影响研究OACSTPCD
Comparison of different turbulence models for simulating water flow in axial pump
[目的]研究湍流模型在轴流泵全工况的数值模拟过程中对计算精度的影响.[方法]采用Standard k-ε、RNG k-ε和SST k-ω 3种湍流模型对轴流泵进行全工况的数值模拟计算,将计算结果和试验结果进行对比并结合内流场进行分析.[结果]在定常状态下,采用Standard k-ε、RNG k-ε、SST k-ω 3种湍流模型计算的扬程曲线与试验曲线的趋势基本一致.在正转逆流制动工况中,采用Standard k-ε和SST k-ω湍流模型计算扬程的精度相近且高于RNG k-ε湍流模型的计算精度,相较于RNG k-ε湍流模型扬程计算最大误差减小了 0.13 m和 0.22 m,平均误差减小了 0.55 m和 0.48 m.在正转水泵小流量工况中,采用Standard k-ε湍流模型计算的扬程值最大误差和平均误差最小,计算精度相对于其他 2种湍流模型显著提高,相较于RNG k-ε和SST k-ω湍流模型扬程计算最大误差减小了 1.19 m和 0.96 m,计算的平均误差减小了 0.56 m和 0.68 m.在反转顺流制动工况中,采用SST k-ω湍流模型计算扬程的精度更高,相较于Standard k-ε和RNG k-ε湍流模型扬程计算最大误差减小了 1.08 m和 1.63 m,计算的平均误差减小了 0.6 m和 0.9 m.在反转水泵工况中,采用Standard k-ε湍流模型计算的计算扬程的精度更高,相较于RNG k-ε和SST k-ω湍流模型扬程计算最大误差减小了 0.65 m和 0.74 m,计算的平均误差减小了 0.34 m和 0.44 m.在正转水泵大流量工况、正转顺流制动工况、正转和反转的水轮机工况中,数值模拟的内流场流态平顺,外特性计算结果较为接近试验值,精度较高,且 3种湍流模型的外特性计算结果相互接近.[结论]在实际轴流泵数值模拟计算中,可以根据不同的运行工况选用计算效果更好的湍流模型来保证计算的结果精确度.研究成果为特殊运行工况的轴流泵的数值模拟计算提供了参考.
[Objective]Water flow in pumps is modeled using computational fluid dynamics(CFD).However,the impact of turbulence model on simulation accuracy remains unexplored.This study aims to address this gap.[Method]We simulated axial water flow in a pump using three turbulent models:the Standard k-ε,RNG k-ε and SST k-ω models.We compared the simulated results with experimental results and analyzed the internal flow fields simulated by different turbulence models.[Result]At steady flow state,the head curves simulated by all three turbulence models were consistent with the experimental curves.Under forward and reverse flow braking conditions,the head calculated by the Standard k-ε and SST k-ω model was close to or slightly higher than that calculated by the RNG k-ε model.Compared to the RNG k-ε model,the Standard k-ε and SST k-ω models reduced the maximum error of calculated head by 0.13 m and 0.22 m,and average error by 0.55 m and 0.48 m,respectively.Under low water flow condition in the forward pump,the maximum and average error of the calculated head by the standard k-ε model were the least;compared to the RNG k-ε and SST k-ω model,it reduced the maximum error of the calculated head by 1.19 m and 0.96 m,and the average error by 0.56 m and 0.68 m,respectively.Under reverse downstream braking conditions,the SST k-ω model was most accurate;compared to the Standard k-ε and RNG k-ε model,it reduced the maximum errors of the calculated head by1.08 m and 1.63 m,and average errors by 0.6 m and 0.9 m,respectively.Under the reverse pump condition,the Standard k-ε was most accurate;compared to the RNG k-ε and SST k-ω models,it reduced the maximum errors of the calculated head by 0.65 m and 0.74 m,and average errors by 0.34 m and 0.44 m,respectively.For other conditions,including positive rotating pump,positive rotating downstream braking,positive rotating and reverse rotating turbine,the simulated internal flow field in the pump was smooth,the simulated external characteristics were close to experimental observations,and simulated results of all three models were similar.[Conclusion]The accuracy of turbulence models for simulating axial water flow in pumps depends on operating conditions.Our results provide insights into selecting appropriate turbulence model for simulating water flow in pumps.
陈迪;张校文;汤方平;王林;许旭东;关子龙
扬州大学 水利科学与工程学院,江苏 扬州 225000江苏省水利科学研究院 材料结构研究所,江苏 扬州 225000
机械工程
湍流模型轴流泵数值模拟计算精度全工况
turbulent flow modelaxial flow pumpnumerical simulationcomputational accuracyall operating conditions
《灌溉排水学报》 2024 (012)
47-56 / 10
国家自然科学基金项目(51809081);江苏省高校优势学科建设项目(PAPD);扬州大学优秀博士学位论文基金项目
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