Conductivity Method For Measurement Of The Water Distribution And Transporting Of The Sand

In this paper, the law of water transporting in soil is cited to study how the water transportin sand under a constant temperature and humidity cases. The moisture content of sand andmixing super absorbent polymers can be measured by electric conductivity through the creationof physical models. We adjust the diffusion coefficient to make the simulation results consistentwith the experiment data. These conclusions can provide reference for further research of watertransport. The conclusions:1. The conductivity of wet sand is linear to the moisture content when water is evenly distributedin sand. If the moisture content below0.12%, the conductivity value decrease to zero. There isno effect to conductivity because the water is assimilated by sand.2. There is a cubic which side lengths both meetL₁=λ₁H,L₂=λ₂L₁. Ifλ₁is fixed, the error ofpotential is increase with increase ofλ₂, the error of moisture content is decrease with increaseofλ₂. The reason is that the big make the potential of the metal net surface diminish, but betterfor water transport. Ifλ₂is fixed, the error of potential and moisture content are diminish withdecrease ofλ₁. The reason is that the error of potential is distributed in a small region aroundmetal net, had no effect on the middle sand. If the size of physical model meetλ₁≤0.1andλ₂=0.8, error of potential and moisture content less than0.53%and0.3%.3. The water rate of the sand that super absorbent polymers evenly distributed is the biggestamong the three situation. The water rate and quality of super absorbent polymers are positivecorrelated.4. The law of water transport in sand.Moisture content changing with time is becoming smaller, the decreasing speed of themoisture content of glass B is less than glass A.The mainly reason is that the water affected by gravity downward transport, the bottom water of glass B is more than glass A, so there is lesswater to be evaporated, the moisture content of glass B is bigger than glass A. The curve of errorand diffusion parameter D0which determined by the total quality is smooth than determined byeach layer of moisture content.5. The law of water transport in sand with super absorbent polymers.The heavier the quality of super absorbent polymers is, the faster the speed of the decline ofthe moisture content is. The moisture content in this case is bigger than the sand without superabsorbent polymers. The greater the quality of super absorbent polymers, the bigger the diffusionparameter D0but the size and the quality of super absorbent polymers is out of multiples.6. The law of water transport in sand with super absorbent polymers in the middle layer.The super absorbent polymers in the middle layer affect the bottom water transport law. Themoisture content of simulation and the moisture content error between simulation andexperiment is about5by input parameters, so it is in good conformity.