Flow Characteristics and Anti-Vortex in a Pump Station with Laterally Asymmetric Inflow

Abstract

In a laterally asymmetric intake pumping station, the flow direction in the forebay is not consistent with flow in the intake channel. Thus, the adverse flow patterns, such as bias flow, large-scale vortex and asymmetric flow occur frequently in the forebay and sump. Based on the Reynolds-averaged Navier-Stokes (RANS) equation and the RNG k-ε turbulence model, a recent flow pattern in a laterally asymmetric intake pumping station was numerically simulated and analyzed, and effective vortex elimination measures were proposed. For the original scheme, seriously biased flow combined with large-scale vortices were observed in the forebay and several vortices occurred in the sump. To suppress the clash inflow in the south and north intake channel, the “straight diversion pier + curved wing wall” and “straight diversion pier + curved wing wall + V-shaped diversion pier” were installed separately. The” symmetrical 川-shaped diversion pier” and “symmetrical 川-shaped diversion pier + circular column” was utilized to eliminate the bias flow and large-scale vortices in the forebay. Finally, the “three- sectional diversion pier”, “three- sectional diversion pier + triangle column” and “three- sectional diversion pier + triangle column + straight back baffle” was applied to decrease the vortex and asymmetric flow near the suction pipe of the sump. By attaching the rectification measure schemes in the intake channel and the forebay, the bias flow and large-scale vortex in the forebay were suppressed to varying degrees. The schemes significantly reduced the recirculation coefficient and greatly reduced the recirculation volume. By utilizing the vortex elimination measures in the sump, the vortex and asymmetric flow basically disappeared, the velocity distribution tended to become more uniform, and the flow rate distinction of each pump was smaller. The outcome can be used to provide a reference and basis for the improvement of flow pattern in similar laterally asymmetric intake pump stations.

Numerical Study on the Influence of Combined Rectification Facilities on the Flow in the Forebay of Pumping Station

“…For these flow characteristics of the forebay, domestic and foreign scholars have carried out research on improving the flow pattern of the forebay and carried out a lot of rectification measures for the forebay. Rtimi et al [12] and Karami et al [13] optimized the base splatter; Li et al [14] and Luo et al [15] added columns to the front pool and designed the columns; Ahmed et al [16] and Zhou et al [17] set different diversion pier layout methods; Xu et al [18] used pressurized water plates for rectification of the front pool. Mi et al [19] set a bottom sill in the forebay to eliminate the influence of eddy current and circulation generated by diffusion flow on pump performance and sediment deposition, and the research results can provide a theoretical basis for improving the flow pattern of the forebay and avoiding sediment deposition.…”

Optimal Design of Perforated Diversion Wall Based on Comprehensive Evaluation Indicator and Response Surface Method: A Case Study

“…At present, some scholars have carried out a series of studies on hydraulic characteristics and optimal design methods of inlet structures in combined sluice-pumping stations, and they have obtained many beneficial results. Luo et al [11][12][13] verified the reliability of numerical simulation results through model experiments and utilized numerical simulation techniques to investigate the adverse flow states existing in different types of pump station forebays and sumps as well as the adjustment and optimization effects of rectification measures on the flow states. By analyzing axial velocity distribution uniformity, velocityweighted average angle and axial average flow velocity of the sump's longitudinal profile, the optimal rectification measures were determined.…”

Study on the Hydraulic Characteristics of an Eccentric Tapering Outlet Pressure Box Culvert in a Pumping Station

“…Therefore, in this paper, the numerical model and the physical model test are combined to optimize the flow pattern of the eccentric tapering outlet pressure box culvert in the original scheme. The combined optimization scheme for the internal structure of the box culvert is discussed, and the hydraulic characteristics of each scheme are studied [19][20][21][22][23]. The analysis process is shown in Figure 1.…”