【摘要】：低水頭樞紐具有水頭低、流量大、低佛汝德數(shù)、消能不充分、閘壩建在覆蓋層較厚的砂礫石河床上等特點,因此閘壩下游護(hù)坦、海漫發(fā)生沖刷破壞的現(xiàn)象較為普遍,甚至導(dǎo)致建筑物損毀,直接影響著泄水閘的安全運行。因此,正確地預(yù)測閘壩下游沖刷坑流場信息、沖刷坑形態(tài)及最大沖刷深度,對于泄水建筑物的安全運行有著非常重要的意義。本文基于Fluent動網(wǎng)格技術(shù),對巨亭水電站泄水閘下游局部沖刷進(jìn)行了三維數(shù)值模擬,得到了以下主要結(jié)論:(1)采用RNG k-ε湍流模型,結(jié)合SIMPLEC算法,利用VOF多相流模型追蹤泄水閘下游復(fù)雜的自由水面,模擬得到了巨亭水電站泄水閘下游沖刷坑三維流場分布,通過分析對比泄流量、沿程水面線和垂線流速分布等結(jié)果表明,數(shù)值模擬值與模型試驗實測值吻合良好,說明數(shù)學(xué)模型計算準(zhǔn)確,結(jié)果可信。(2)基于Fluent動網(wǎng)格技術(shù),采用VOF模型追蹤自由水面,在對Fluent軟件進(jìn)行二次開發(fā)中,以床面水流剪切應(yīng)力大于泥沙起動切應(yīng)力作為網(wǎng)格移動的判別標(biāo)準(zhǔn),基于彈簧光順模型及局部網(wǎng)格重構(gòu)模型,對單個橋墩局部沖刷進(jìn)行了三維數(shù)值模擬,得到的沖刷坑形態(tài)及最大沖刷深度與模型試驗結(jié)果吻合良好,驗證了本文二次開發(fā)子程序的可靠性。(3)實現(xiàn)了泄水閘下游局部沖刷坑沖刷過程的三維數(shù)值模擬,得到的沖刷坑形態(tài)及最大深度與物理模型實測值吻合良好。(4)在沖刷坑的沖刷過程中,床面切應(yīng)力逐漸減小;中軸面湍動能的變化規(guī)律與湍動能耗散率的變化規(guī)律基本相似。在沖刷初始階段,挑坎末端床面附近的湍動能和湍動能耗散率均較大;隨著沖刷的進(jìn)行,沖刷后的湍動能和湍動能耗散率明顯減小;在沖刷坑達(dá)到平衡狀態(tài)時,沖刷坑區(qū)域的湍動能和湍動能耗散率均較小。
[Abstract]:The low head hub has the characteristics of low head, large discharge, low Froude number, insufficient energy dissipation, and the dam is built on the sand and gravel river bed with thick overburden. Therefore, the downstream of the dam protects the dam and the sea overflows with scour damage is more common. Even lead to damage to buildings, directly affect the safe operation of the sluice. Therefore, it is very important to correctly predict the flow field information, the shape of the scour pit and the maximum scour depth of the downstream sluice dam for the safe operation of the drainage structure. Based on the Fluent dynamic grid technology, the local scour downstream of the sluice of Juting Hydropower Station is simulated by 3D numerical simulation. The main conclusions are as follows: (1) the RNG k- 蔚 turbulence model is adopted, and the SIMPLEC algorithm is used to simulate the local scour of the sluice downstream of Juting Hydropower Station. VOF multiphase flow model is used to track the complex free water surface downstream of the sluice gate, and the three-dimensional flow field distribution of the scour pit downstream of the sluice of Juting Hydropower Station is simulated. The results of analysis and comparison of the discharge, the velocity distribution along the water surface line and the vertical line, etc. The numerical simulation results are in good agreement with the measured values of the model test, which shows that the mathematical model is accurate and the results are reliable. (2) based on the Fluent dynamic grid technology, the VOF model is used to track the free water surface, and in the secondary development of Fluent software, Based on spring fairing model and local mesh reconstruction model, the local scour of a single pier is simulated with the criterion that the shear stress of the bed surface is greater than the initial shear stress of sediment. The obtained scour pit shape and maximum scour depth agree well with the model test results, which verify the reliability of the secondary development subroutine in this paper. (3) the 3D numerical simulation of the local scour pit scour process downstream of the sluice is realized. The shape and maximum depth of the scour pit are in good agreement with the measured values of the physical model. (4) during the scouring process of the scour pit, the bed shear stress decreases gradually; The law of variation of turbulent kinetic energy in central axis is similar to that of turbulent kinetic energy dissipation rate. In the initial stage of scour, the turbulent kinetic energy and turbulent kinetic energy dissipation rate near the bed surface at the end of the scour are both large, and with the scouring, the turbulent kinetic energy and turbulent kinetic energy dissipation rate after scouring obviously decrease. When the scour pit reaches equilibrium, the turbulent kinetic energy and turbulent kinetic energy dissipation rate are smaller.
【學(xué)位授予單位】：西北農(nóng)林科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TV149

【相似文獻(xiàn)】

相關(guān)期刊論文 前10條

1 鄭英;;東流水道沖刷坑系列正態(tài)模型研究[J];科學(xué)技術(shù)與工程;2010年07期

2 韓曾萃;陳森美;伍冬領(lǐng);;河口海岸凸體沖刷坑最大深度及形態(tài)[J];海洋工程;2007年02期

3 張修忠,王光謙;堤防潰決的流動分析及沖刷坑計算[J];泥沙研究;2002年01期

4 潘軍峰,馮民權(quán),鄭邦民,閔濤;丁壩繞流及局部沖刷坑二維數(shù)值模擬[J];四川大學(xué)學(xué)報(工程科學(xué)版);2005年01期

5 張洪霞;封光寅;柳發(fā)忠;林云發(fā);余國莉;;丹江口水利樞紐壩區(qū)下游沖刷坑變化分析[J];人民長江;2006年12期

6 施振興;;池式戽防沖計算與體型優(yōu)化[J];水利水運科學(xué)研究;1992年04期

7 季永興,李國林,莫敖全,刁南興;長興島南沿丁壩壩頭沖刷坑深度探析[J];人民長江;2002年04期

8 冷魁;橋墩施工期沉井附近流速變化及對沖刷坑的影響[J];武漢水利電力大學(xué)學(xué)報;1993年02期

9 劉沛清，李永祥，冬俊瑞，，李玉柱;平衡沖刷坑的穩(wěn)定性條件與堆丘位置的確定[J];水利學(xué)報;1996年02期

10 周麗麗;郭維東;閆濱;董延超;李海欣;;彎曲溢洪道挑流消能沖刷坑的研究[J];沈陽農(nóng)業(yè)大學(xué)學(xué)報;2008年03期

相關(guān)會議論文 前4條

1 黃健華;;洪口水電站沖刷坑工程地質(zhì)條件分析研究[A];福建省水力發(fā)電工程學(xué)會2006年學(xué)術(shù)論文匯編[C];2006年

2 黃健華;;洪口水電站沖刷坑工程地質(zhì)條件分析研究[A];福建省科協(xié)第六屆學(xué)術(shù)年會分會場——碾壓混凝土及筑壩技術(shù)發(fā)展研討會論文集[C];2006年

3 趙小娥;陳春燕;王協(xié)康;孫一;;潰堤洪水及沖刷坑的平面二維數(shù)值模擬[A];中國水利學(xué)會2013學(xué)術(shù)年會論文集——S3防汛抗旱減災(zāi)[C];2013年

4 張芝永;員鵬;吳修廣;劉光生;;移動射流沖刷數(shù)值模擬研究[A];第十三屆全國水動力學(xué)學(xué)術(shù)會議暨第二十六屆全國水動力學(xué)研討會文集——G海岸環(huán)境與地球物理流體力學(xué)[C];2014年

相關(guān)碩士學(xué)位論文 前5條

1 吳彰松;閘壩下游沖刷坑形態(tài)三維數(shù)值模擬[D];西北農(nóng)林科技大學(xué);2017年

2 施如學(xué);丁壩沖刷坑的三維水流流態(tài)數(shù)值模擬[D];重慶交通大學(xué);2014年

3 高改玉;橫丹水電站水流三維模擬及下游沖刷坑二維模擬[D];西北農(nóng)林科技大學(xué);2013年

4 王新強(qiáng);當(dāng)卡水電站下游沖刷坑形態(tài)的試驗研究[D];西北農(nóng)林科技大學(xué);2014年

5 孫小玲;線性水波越過三維非理性地形散射效應(yīng)的解析模擬[D];廣西民族大學(xué);2012年

本文編號：2315336