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空蚀区空化水流特性的实验研究 被引量:5
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作者 颜效凡 董志勇 +1 位作者 韩伟 俞小伟 《浙江工业大学学报》 CAS 2012年第2期193-195,225,共4页
实验研究了空蚀区空泡溃灭特性.实验在浙江工业大学水力学实验室空化水洞中进行,采用高速摄影技术观测了不同掺气体积分数下空蚀段的空化云形态,并量测了空化水流的压力.利用绘制的空化数曲线对空泡溃灭进行了分析处理,得到了空化水流... 实验研究了空蚀区空泡溃灭特性.实验在浙江工业大学水力学实验室空化水洞中进行,采用高速摄影技术观测了不同掺气体积分数下空蚀段的空化云形态,并量测了空化水流的压力.利用绘制的空化数曲线对空泡溃灭进行了分析处理,得到了空化水流在空蚀段沿程变化的特征.结果表明:在不同的掺气体积分数下,对应于各种不同的空化形态,空蚀段空化水流表现出不同的特点;空化数有一个突然上升的过程,在此过程中空泡大量溃灭. 展开更多
关键词 化水流特性 空蚀区 高速摄影技术
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考虑空蚀振动区的水电站厂内经济运行方法研究 被引量:9
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作者 周冉 杨侃 +2 位作者 郝永怀 郑姣 刘国帅 《中国农村水利水电》 北大核心 2011年第6期153-155,共3页
机组在实际运行中处于某些出力范围时会产生振动,这给厂内经济运行方法研究增加了难度。通过引入惩罚因子,对处于空蚀振动区的流量特性曲线进行变换处理,在此基础上应用动态规划方法得到水电站厂内最佳运行方式。并以三峡左岸电站为实例... 机组在实际运行中处于某些出力范围时会产生振动,这给厂内经济运行方法研究增加了难度。通过引入惩罚因子,对处于空蚀振动区的流量特性曲线进行变换处理,在此基础上应用动态规划方法得到水电站厂内最佳运行方式。并以三峡左岸电站为实例,制定了考虑空蚀振动区的最佳负荷分配方案。 展开更多
关键词 水电站 经济运行 振动 动态规划
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浓度对大直径管道内料浆输送特性的影响 被引量:1
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作者 甘德清 高锋 +2 位作者 孙光华 邵静静 侯永康 《金属矿山》 CAS 北大核心 2015年第6期38-42,共5页
以大直径管道输送超细全尾砂胶结充填料浆技术为研究对象,构建大直径输送管道三维模型,基于三维单精度解算器Fluent-3D中Reliable k-epsilon模型,研究大直径管道内浓度对超细全尾砂胶结充填料浆输送特性的影响。结果表明,在充填倍线为3... 以大直径管道输送超细全尾砂胶结充填料浆技术为研究对象,构建大直径输送管道三维模型,基于三维单精度解算器Fluent-3D中Reliable k-epsilon模型,研究大直径管道内浓度对超细全尾砂胶结充填料浆输送特性的影响。结果表明,在充填倍线为3的条件下,灰砂比为1∶6的超细全尾砂胶结充填料浆在200 mm直径管道中输送时,在弯管下部内侧管壁位置出现空蚀区,随着浓度的增大,空蚀区范围先增大,后趋于稳定;随料浆浓度的增大,浓度小于64%时,管内料浆平均流速线性增长,料浆浓度大于64%时,管内料浆平均流速先增大后减小;随着料浆浓度的增大,浓度小于68%时,料浆在管内流动的压力损失以较大速率增长,浓度大于68%时,料浆流动的压力损失增长缓慢。研究认为,66%浓度为200 mm直径管道输送超细全尾砂胶结充填料浆的最佳输送浓度。 展开更多
关键词 大直径管道 料浆浓度 空蚀区范围 平均流速 压力损失
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Gully Erosion Regionalization of Black Soil Area in Northeastern China 被引量:16
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作者 YANG Jiuchun ZHANG Shuwen +3 位作者 CHANG Liping LI Fei LI Tianqi GAO Yan 《Chinese Geographical Science》 SCIE CSCD 2017年第1期78-87,共10页
Gully erosion is the frequent and main form of soil erosion in the black soil area of the northeastern China, which is one of the most important commodity grain production bases in China. It is encroaching upon the fe... Gully erosion is the frequent and main form of soil erosion in the black soil area of the northeastern China, which is one of the most important commodity grain production bases in China. It is encroaching upon the fertile farmland there. Regionalization of gully erosion can reveal the spatial distribution and regularity of the development of gully erosion. Based on the eco-geographical regional background features of the black soil area, this study combined the regionalization with influencing factors of the development of gully erosion. GIS spatial analysis, geostatistical analysis, spatial statistics, reclassification, debris polygon processing and map algebra methods were employed. As a result, the black soil area was divided into 12 subregions. The field survey data on type, length, volume and other characteristics indicators of gully erosion were used to calibrate the results. Then the features of every subregion, such as where the gully erosion is, how serious it is, and why it happens and develops, were expounded. The result is not only an essential prerequisite for gully erosion surveys and monitoring, but also an important basis for gully erosion prevention. 展开更多
关键词 regionalization gully erosion soil and water conservation black soil area northeastern China
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Spatial and temporal change patterns of freeze-thaw erosion in the three-river source region under the stress of climate warming 被引量:5
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作者 GUO Bing LUO Wei +1 位作者 WANG Dong-liang JIANG Lin 《Journal of Mountain Science》 SCIE CSCD 2017年第6期1086-1099,共14页
The three-river source region(TRSR), located in the Qinghai-Tibet Plateau in China, suffers from serious freeze-thaw(FT) erosion in China. Considering the unique eco-environment and the driving factors of the FT proce... The three-river source region(TRSR), located in the Qinghai-Tibet Plateau in China, suffers from serious freeze-thaw(FT) erosion in China. Considering the unique eco-environment and the driving factors of the FT process in the TRSR, we introduce the driving force factors of FT erosion(rainfall erosivity and wind field intensity during FT period) and precipitation during the FT period(indicating the phase-changed water content). The objective was to establish an improved evaluation method of FT erosion in the TRSR. The method has good applicability in the study region with an overall precision of 92%. The spatial and temporal changes of FT erosion from 2000 to 2015 are analyzed. Results show that FT erosion is widely distributed in the TRSR, with slight and mild erosion being the most widely distributed, followed by moderate erosion. Among the three sub-regions, the source region of the Yellow River has the slightest erosion intensity, whereas the erosion intensity of the source region of Yangtze River is the most severe. A slight improvement can be observed in the condition of FTerosion over the whole study region from 2000 to 2015. Vegetation coverage is the dominant factor affecting the intensity of FT erosion in the zones with sparse vegetation or bare land, whereas the climate factors play an important role in high vegetation coverage area. Slopes>28° also have a significant effect on the intensity of FT erosion in the zones. The results can provide a scientific basis for the prevention and management of the soil FT erosion in the TRSR. 展开更多
关键词 Freeze-thaw erosion Vegetation Precipitation Three-river source region Global warming
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