基于FEKO7.0建立了矿井无线透地通信磁场模型,设计了3种体积不同、匝数不同但输入电阻相同的铁氧体磁性天线,研究了该模型在地面上的磁场分布情况,频率采用甚低频15 k Hz。结果表明:这3种铁氧体模型在地面上产生了3种不同数量级的磁场强...基于FEKO7.0建立了矿井无线透地通信磁场模型,设计了3种体积不同、匝数不同但输入电阻相同的铁氧体磁性天线,研究了该模型在地面上的磁场分布情况,频率采用甚低频15 k Hz。结果表明:这3种铁氧体模型在地面上产生了3种不同数量级的磁场强度,并采用竖直和水平两种安装方式,其量值都在电磁传感器可以检测到的范围内。研究发现,地面产生磁场强度的大小与铁氧体天线的体积和放置形式有关,水平放置比竖直放置产生了较大的磁场强度。因而,利用磁场代替调制电磁波作为矿井无线透地通信的传输媒介是可行的。展开更多
Based on the distribution state of the combustibles and the scale of the fires in underground mines, mine fire sources are divided into two types in this paper,namely, fixed point fire source and movable linear fire s...Based on the distribution state of the combustibles and the scale of the fires in underground mines, mine fire sources are divided into two types in this paper,namely, fixed point fire source and movable linear fire source. By analying a lot of ex periment results of mine fires, the authors studied the combustion characteristics of the two types of fire source, and have set up their mathematical models. The models have further been applied to calculate the concrete mine instances and the obtained re sults corresponded with the reality.展开更多
文摘基于FEKO7.0建立了矿井无线透地通信磁场模型,设计了3种体积不同、匝数不同但输入电阻相同的铁氧体磁性天线,研究了该模型在地面上的磁场分布情况,频率采用甚低频15 k Hz。结果表明:这3种铁氧体模型在地面上产生了3种不同数量级的磁场强度,并采用竖直和水平两种安装方式,其量值都在电磁传感器可以检测到的范围内。研究发现,地面产生磁场强度的大小与铁氧体天线的体积和放置形式有关,水平放置比竖直放置产生了较大的磁场强度。因而,利用磁场代替调制电磁波作为矿井无线透地通信的传输媒介是可行的。
文摘Based on the distribution state of the combustibles and the scale of the fires in underground mines, mine fire sources are divided into two types in this paper,namely, fixed point fire source and movable linear fire source. By analying a lot of ex periment results of mine fires, the authors studied the combustion characteristics of the two types of fire source, and have set up their mathematical models. The models have further been applied to calculate the concrete mine instances and the obtained re sults corresponded with the reality.