农业工程学报
農業工程學報
농업공정학보
2015年
7期
100-108
,共9页
罗灿%钱均%刘超%陈锋%许健%周庆连
囉燦%錢均%劉超%陳鋒%許健%週慶連
라찬%전균%류초%진봉%허건%주경련
泵%墩%流态%前池%泵站%数值模拟
泵%墩%流態%前池%泵站%數值模擬
빙%돈%류태%전지%빙참%수치모의
pumps%piers%flow patterns%forebay%pump station%numerical simulation
闸站结合式泵站运行时,隔墩前池侧存在严重的不良流态,危害到进水流道进口断面的入流流态。该文采用数值模拟手段对前池内的流动进行预测,并对预测结果进行了试验验证。研究结果表明:原方案靠近隔墩的前池内有大尺度的回流区,该回流从隔墩处一直延伸到靠近流道进口前的横剖面,1#进水流道进口断面上的轴向速度分布较为均匀,呈现出上下、左右对称的趋势,高速区位于断面中心,5#进水流道进口断面上的轴向速度分布不均匀,高速区迁移到断面左侧。分别采取2种导流墩整流措施对前池流态进行调整,与原方案相比,这2种整流措施均能缩小回流区的范围,并改善和提高4#和5#进水流道进口断面上的流速分布和轴向速度分布均匀度。通过定量和定性地对比试验测试结果和数值预测结果发现,二者吻合性较好,数值预测结果得到了验证,这表明该数值计算过程是可靠的,其预测结果是可信的。
閘站結閤式泵站運行時,隔墩前池側存在嚴重的不良流態,危害到進水流道進口斷麵的入流流態。該文採用數值模擬手段對前池內的流動進行預測,併對預測結果進行瞭試驗驗證。研究結果錶明:原方案靠近隔墩的前池內有大呎度的迴流區,該迴流從隔墩處一直延伸到靠近流道進口前的橫剖麵,1#進水流道進口斷麵上的軸嚮速度分佈較為均勻,呈現齣上下、左右對稱的趨勢,高速區位于斷麵中心,5#進水流道進口斷麵上的軸嚮速度分佈不均勻,高速區遷移到斷麵左側。分彆採取2種導流墩整流措施對前池流態進行調整,與原方案相比,這2種整流措施均能縮小迴流區的範圍,併改善和提高4#和5#進水流道進口斷麵上的流速分佈和軸嚮速度分佈均勻度。通過定量和定性地對比試驗測試結果和數值預測結果髮現,二者吻閤性較好,數值預測結果得到瞭驗證,這錶明該數值計算過程是可靠的,其預測結果是可信的。
갑참결합식빙참운행시,격돈전지측존재엄중적불량류태,위해도진수류도진구단면적입류류태。해문채용수치모의수단대전지내적류동진행예측,병대예측결과진행료시험험증。연구결과표명:원방안고근격돈적전지내유대척도적회류구,해회류종격돈처일직연신도고근류도진구전적횡부면,1#진수류도진구단면상적축향속도분포교위균균,정현출상하、좌우대칭적추세,고속구위우단면중심,5#진수류도진구단면상적축향속도분포불균균,고속구천이도단면좌측。분별채취2충도류돈정류조시대전지류태진행조정,여원방안상비,저2충정류조시균능축소회류구적범위,병개선화제고4#화5#진수류도진구단면상적류속분포화축향속도분포균균도。통과정량화정성지대비시험측시결과화수치예측결과발현,이자문합성교호,수치예측결과득도료험증,저표명해수치계산과정시가고적,기예측결과시가신적。
In the combined sluice-pump station project, adverse flow pattern always happens in the forebay, which will result in the unfavorable inflow pattern on the inlet section of the passage intake. Based on this, the physical experiment device and computational domain are prepared separately, which share the same dimensions and parts containing a diversion canal, passage intake, forebay, diversion pier and, check gate, so that the flow in the forebay is predicted and verified by the test data at the model water level which is 0.125m, corresponding to the prototype water level of 2.5m. The velocities of the measure points on the chosen sections in the forebay is measured with a LGY-Ⅱintelligent velocity instrument and recorded. To gain the steady flow in the test rig, the flow rate was adjusted depending on the valve and electromagnetic flowmeter. In order to better understand the inner detail flow structure in the forebay, several analysis planes which are the surface plane, the bottom plane, the inlet of passage intakes 1#, 4#, and 5#, and the plane before the passage intake are sliced. In the original case, the crosswise velocity of the main forward flow around the diversion pier is large which leads to a deflective flow. With the effect of viscous force, the neighboring water changes its direction, and brings out a larger scale bias flow. Then the water changes its direction again, due to the low pressure zone, and across flow occurs once more whose direction is opposite to the initial cross flow. At last, the water moves along the diversion pier to the inlet of forebay, where a mixed flow takes place and the steady large circulation zone starts from the isolated pier to the cross-section which is close to the inlet of the passage intake in the forebay is produced. The axial velocity distribution is uniform and left-right&up-down symmetry on the inlet of passage intake 1#, the high velocity area is in the center of the section. The axial velocity distribution is not uniform on the inlet of passage intake 5#, and the high velocity area is on the left of the inlet. To solve the problem, a single long diversion pier and the combined measures of“long diversion pier + short diversion pier” were put forward which were marked as improvement scheme 1 and 2. Compared with the original case, the recirculation zone was decreased and advanced with both measures, and the water could be smoothly guided into passage intake 4#. The axial velocity distribution on the inlet of passage intake with both rectification measures was well improved. For passage intake 1#, 4#, and 5#, axial velocity distribution increased 2.6%, 7.8%, and3.6%respectively with improvement scheme 1, as well as 2.7%, 18%, and 1.8%with improvement scheme 2. As a whole, rectification results with improvement scheme 2 were better than improvement scheme 1, but the structure of improvement scheme 1 is simple and convenient for construction. By discussing the calculated and test average axial velocity, the maximum and minimum relative error was 6.29%and 0.63%respectively. After a single long diversion pier was installed, the standard deviation of calculated and test axial velocities decreased. The calculated results were well satisfied with test results and the prediction well verified and credible.