Compressed air energy storage (CAES) is a technology that uses compressed air to store surplus electricity generated from low power consumption time f

Laboratory experiments were conducted on three artificial rock joints with natural characteristics to study the nonlinear fluid flow characteristics in a single joint under different contact conditions. A noncontact, three-dimensional stereotopometric measurement instrument was used to measure the three-dimensional surface morphology of rock joints before they were tested. Subsequently, the composite morphology parameters of rock joints under different contact conditions were calculated by using self-programmed software. The experimental results showed that both the Forchheimer’s equation (emphatically discussed) and Izbash’s equation could provide an excellent description for the nonlinear fluid flow in a single joint. The linear coefficient a and nonlinear coefficient b of the Forchheimer’s law both generally decreased, and such rate of decrease was gradually reduced along with increasing offset distance. The value of linear coefficient a approached zero and the value of coefficient n was close ...