摘要
本研究设计并建立了一维和二维实验装置,通过水的入渗来驱动气相流动从而营造出水气二相流的流场,并通过监测水的累积入渗量和湿润峰前进情况及流场内各监测点气体的压力变化来研究水气二相流。本实验采用压力传感器并设计了气压自动采集系统来监测并记录一维及二维土柱中气体的压力变化,在土柱的底部出气口,用带阀门的微量流量计来控制并调节气体的出流速率。在一维入渗实验中,我们发现在控制气体出流的情况下水的入渗速率比在没有控制的情况下有所减少。在控制气体出流的实验中,水的入渗速率对应于气体的出流速率有对应的变化,并且总是较气体出流速率大。在二维实验中我们发现,水的入渗速率及空气的压缩程度均为在垂向较为横向大。此外,我们还得到了不同时刻空气压力的等值线图,通过空气压力等值线图可以看出在供水槽与出气口之间的连线的直线方向上,空气的流动最强烈。
When water flows through the vadose zone, there is not only water inflow but also air inflow. In this study, a one-dimension infiltration and two-dimension infiltration experimental apparatus was designed and built up. We got the two-phase flow field by driving the airflow with water infiltration and recorded and monitored the water accumulative infiltration volume, wetting front and the air pressure within the two-phase flow field to study the two-phase flow. One-dimension and two-dimension two-phase flow experiments were conducted to determine effect of air compression on the infiltration of water under different air outflow rates, the change in air pressure and the air movement. The pressure sensors connected with the automatic pressure monitor system were used to monitor and record the change in air pressure in 1-D and 2-D soil column. The micro gas flowmeter with valves was connected with the soil column at its bottom to control and regulate the air outflow rate. In 1-D experiment, we found that without controlling the air outflow the water inflow rate was reduced compared with the water inflow rate under the condition, as observed by other researchers. When the air outflow rate varied, the water inflow rate changed accordingly, but always remained bigger than the former. In 2-D experiment, it is found that the water inflow-rate in vertical direction was bigger than that in horizontal direction. Finally, we got air pressure contour figures at different times. From these figures, it is discovered that the airflow was most vehement along the line between the water trench and the air vent in the bottom of the soil box.
出处
《土壤学报》
CAS
CSCD
北大核心
2002年第4期505-511,共7页
Acta Pedologica Sinica
基金
中国辐射防护研究院国际合作资助项目(项目编号:CJ2-A-7)
