under water head condition 中文意思是什麼
under water head condition
解釋
水壓作用條件下-
Using a vortex - flow drop shaft to convey water from a high level to a diversion runnel under the condition of high water - head and large discharge is a new kind of technology in the scheme of reusing a diversion tunnel as a discharge tunnel
近年來，為解決高水頭、大流量導流洞改建泄洪洞的技術難題，旋流式豎井泄洪洞逐漸成為研究熱點之一。但迄今為止，該技術尚未得到推廣應用，其主要原因在於人們對豎井螺旋水流運動特徵缺乏足夠的了解和深入的研究。 -
In this thesis hydraulic experimental studies and theoretical analyses on the vortex - flow drop shaft were conduced and the following results were accomplished : ( 1 ) in the model test some hydraulic characteristics including the shape of air core in the center of the drop shaft, the radial distribution of water flow velocity and the distribution of pressure on the wall of the drop shaft were measured under the condition of high water head above 250m and large discharge above 1400m3 / s. ( 2 ) a kind of computational method for the spiral water flow in the air core region of drop shaft was discussed and applied and the results agree the experimental data well. ( 3 ) the total ratio of energy dissipation in the drop shaft can reach 90 % and the energy dissipation in every region was discussed quantitatively
本文通過試驗研究與理論分析對旋流式豎井泄洪洞應用於高水頭、大泄流量情況時存在的一些水力學問題進行了研究和探討，取得以下主要成果：一、結合小灣工程導流洞改建，對高水頭（ 252m ） 、大泄流量（ 1400m ~ 3 s ）條件下旋流式豎井中的水流運動特徵進行了比較全面的測量，包括空腔形態、徑向流速分佈及井壁壓強等；二、提出了豎井空腔段螺旋水流水力計算方法，其計算結果與實測值吻合良好；三、利用試驗與計算結果，對旋流式豎井的消能機理進行了探討，對豎井各部分的消能能力有了總體認識；四、對豎井下部消力井的合理井深進行了優化試驗研究，發現消力井合理深度為0 . 9d左右；五、通過試驗研究，歸納出豎井水流總摻氣量估算方法，為導流洞排氣方案的設計提供了參考依據；六、在高水頭、大流量條件下，豎井空腔段下部流速很高，盡管水流螺旋運動引起的離心力可以確保井壁壓強保持正壓，但空化數依然較低，因此豎井的空化空蝕始終是工程界關注的重大問題。 -
The result shows that the drainage curtain is of high drainability under smooth drainage condition, and that the variation of the spacing between drainage holes within a certain range is of little influence on the water head distribution of the seepage field
研究表明，排水幕在排水通暢的前提下具有強大的排水能力，其排水孔間距在一定范圍內變化對滲流場水頭分佈影響不明顯。 -
Based on experimental result of energy dissipation and scour protection for downstream of spillway at yu jian kou power station, this paper discusses the flow characteristics, aerated characteristics of flaring gate pier for low dam pivot, the influence on pressure of dam surface and the result of energy dissipation for flaring gate pier. it is put forward to be an available method to solve the problems of energy dissipation and scour protection for depth of covering strata, poor geologic condition and weakness of resistance to scour capability under reasonable use of flaring gate piers and auxiliary dissipaters. thus, a new method is obtained for release of floodwater and energy dissipation of low dam pivot which are provided with low water head, great unit discharge and low froud coefficient. it may be used for reference for design and test workers
結合魚劍口電站壩下消能防沖試驗研究成果，對低壩樞紐寬尾墩的水流特點、摻氣特性、寬尾墩對大壩泄流能力和壩面壓力的影響以及寬尾墩的消能效果等問題進行了初步探討，提出了合理地使用寬尾墩結合輔助消能設施可有效地解決壩下覆蓋層深，地質條件差，抗沖能力弱的低壩樞紐的消能防沖問題，從而為具有低水頭，大單寬流量，低佛氏數特點的低壩樞紐泄洪消能開辟了一條新途徑，可供有關低壩樞紐設計與試驗工作者借鑒與參考 -
Until now, there have been a few reports on the damage of the water pumps caused by sand and water cavitation. by use of the test loop for solid and liquid two phases, under the condition of 3 % head drop, the damage location and relative degree of the sand and water cavitaiton occurred on the impeller were tested and researched. the result was, them, compared with the results under the condition that water cavitation occurred and no cavitation but only wear occurred. the differencts were analyzed. the analysis result can be used as the basis of the further research and the improvement of the impeller shape
目前含沙水汽蝕對水泵損傷方面的報導甚少，本文利用固液兩相流試驗臺，對離心泵閉式葉輪在含沙水汽蝕時（ 3揚程下降點）的損傷部位和相對程度進行了試驗研究，並將此結果與清水介質發生汽蝕時的損傷情況[ 13 ]及含沙水無汽蝕情況下的磨損情況[ 7 ]相比較，對其差異進行了分析，為今後進一步探討葉輪損傷機理和葉型改進提供了實驗依據。 -
Abstract : based on experimental result of energy dissipation and scour protection for downstream of spillway at yu jian kou power station, this paper discusses the flow characteristics, aerated characteristics of flaring gate pier for low dam pivot, the influence on pressure of dam surface and the result of energy dissipation for flaring gate pier. it is put forward to be an available method to solve the problems of energy dissipation and scour protection for depth of covering strata, poor geologic condition and weakness of resistance to scour capability under reasonable use of flaring gate piers and auxiliary dissipaters. thus, a new method is obtained for release of floodwater and energy dissipation of low dam pivot which are provided with low water head, great unit discharge and low froud coefficient. it may be used for reference for design and test workers
文摘:結合魚劍口電站壩下消能防沖試驗研究成果，對低壩樞紐寬尾墩的水流特點、摻氣特性、寬尾墩對大壩泄流能力和壩面壓力的影響以及寬尾墩的消能效果等問題進行了初步探討，提出了合理地使用寬尾墩結合輔助消能設施可有效地解決壩下覆蓋層深，地質條件差，抗沖能力弱的低壩樞紐的消能防沖問題，從而為具有低水頭，大單寬流量，低佛氏數特點的低壩樞紐泄洪消能開辟了一條新途徑，可供有關低壩樞紐設計與試驗工作者借鑒與參考
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