Analytical solution of heat pulse method in a parallelepiped sample space with inclined needles
Analytical solution of heat pulse method in a parallelepiped sample space with inclined needles
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DOI：
10.2136/sssaj2007.0260
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发表时间：
2008-09-01
影响因子：
2.9
通讯作者：
Si, Bing C.
中科院分区：
文献类型：
--
作者：
Liu, Gang;Li, Baoguo;Si, Bing C.
拍脉冲法能够估计土壤热扩散率（k）、体积热容（C）、导热率和含水量。在探头插入土壤期间，加热器针和温度传感针可能偏转。针偏转对C和k的估计的影响尚未在理论上或实验上被充分研究。我们定义θ为针偏离z轴的极角，并且Φ为x-y平面中的方位角。在零表面温度和绝热边界条件下，导出了平行六面体样品中所有倾斜和脉冲有限线源的瞬态解析解。对于针间距为6 mm的热脉冲传感器和给定平行六面体（5 × 5 × 5 cm，假设填充有风干砂）中长度为4 cm的加热器针，对于θ = 1度和φ = 0度的倾斜加热器针，C和k的模型误差分别约为-11.3和12.1%。对于θ = 1度和φ = 180度的倾斜传感器针，C和k的模型误差分别约为-11.2%和12.1%。当-6
The beat pulse method enables estimation of soil thermal diffusivity (k), volumetric heat capacity (C), thermal conductivity, and water content. The heater needle and temperature-sensing needle may deflect during probe insertion into soils. The impact of needle deflection on estimates of C and k has not been fully studied theoretically or experimentally We defined theta to be the polar angle of needle deviation from the z axis and phi to be the azimuthal angle in the x-y plane. Transient-state analytical Solutions were derived for all inclined and Pulsed finite line source in a parallelepiped sample with Zero Surface temperature and adiabatic boundary conditions. For a heat Pulse sensor with 6-mm needle spacing and a heater needle of 4-cm length in a given parallelepiped (5 by 5 by 5 cm, assumed to be filled with air-dry sand), model errors in C and k were about -11.3 and 12.1%, respectively, for an inclined heater needle with theta = 1 degrees and phi = 0 degrees. Model errors in C and k were about -11.2 and 12.1% respectively, for an inclined sensor needle with theta = 1 degrees and phi = 180 degrees. When -6