CFD simulation parameter settings.

The tracer gas wind measurement method must measure the average concentration based on the known mixing distance of the tracer gas in order to accurately calculate the air volume. we established a T-shaped cross-ventilation duct with a square cross-sectional side of 0.3 m to simulate mine tunnels experimentally, and created the above duct model in Fluent software. Using the renormalization group (RNG k-ε) and detached eddy simulation (DES) models in Fluent to calculate the concentration and mixing distance of sulfur hexafluoride (SF6) tracer gas in air collection duct, and conducted SF6 blending experiments. In the first 7m stage of air collection duct, the SF6 mixing rate in the experiment was the fastest, while the RNG k-ε model was the slowest. However, after 7 meters, the mixing rate in the experiment rapidly slowed down, while there was no significant change in the RNG k-ε model. The rate of change of the DES model was between the above two results, but the concentration change was the most unstable. And the mixed distance results of the three were highly consistent. The results of this study provide a reference for selecting appropriate numerical simulation models for future calibration work of mine ventilation systems.为精准计算风量，示踪气体测风法（tracer gas wind measurement method）需基于示踪气体的已知混合距离测定平均浓度。本研究搭建了横截面为边长0.3米正方形的T型交叉通风管道以实验模拟矿井巷道，并在Fluent软件中构建了该管道的仿真模型。采用Fluent软件中的重整化群（renormalization group，RNG k-ε）模型与分离涡模拟（detached eddy simulation，DES）模型，对集气管道内六氟化硫（sulfur hexafluoride，SF6）示踪气体的浓度与混合距离进行数值计算，并开展了SF6掺混实验。在集气管道的前7米区段，实验测得的SF6混合速率最快，而RNG k-ε模型的混合速率最慢；但在7米之后，实验中的混合速率迅速放缓，而RNG k-ε模型的混合速率无显著变化。分离涡模拟（DES）模型的变化速率介于上述两者之间，但其浓度变化最为不稳定。三者的混合距离结果则具有高度一致性。本研究结果可为后续矿井通风系统校准工作选取合适的数值模拟模型提供参考依据。