Simulation analysis of flow lengths for fully developed turbulence under disturbance conditions
Changes in underground roadways can disturb airflow,affecting the original stable airflow state.It is essential to consider avoiding the influence range of such disturbances when placing cross-sectional wind speed monitoring points to ensure data accuracy.To investigate the extent and range of roadway disturbance conditions'effect on airflows inside roadways,the required flow lengths for fully developed turbulence under various disturbance conditions were summarized.Numerical simulation was employed to establish airflow disturbance fluid models under different scenarios,including roadway bends,abrupt changes in cross-section,and intersections.FLUENT software was used to simulate and calculate the disturbance models under varying wind speeds.The results indicate that the fully developed turbulence flow length is minimally influenced by variations in wind speed at the inlet,and changes in airflow speed inside the roadway have a minor impact on the fully developed turbulence flow length.However,the disturbance conditions significantly affect the flow length under the same roadway roughness conditions.Specific findings include:airflow disturbance distance due to right-angle bends is 24.14 m;airflow disturbance distance due to abrupt expansions is 12.25 m;airflow disturbance distance due to merging flows is 27.93 m;airflow disturbance distance due to splitting flows is 33.45 m.These results provide theoretical guidance for the layout of monitoring points in underground mine ventilation systems,which is significant in improving the accuracy of ventilation monitoring under corresponding conditions.
万方数据
维普
