Research On Airflow Turbulence Simulation In Fire Accident On Underground Mine Tunnel

In recent years, there are more and more underground mine tunnel fire accidents, which bring enormous disaster to people, thus it is a significant research in state of airflow on mine tunnel fire accidents. In mine fire period, the fire develops rapidly and changes complicatedly. Correct measure of charging wind can be effective to rescue fire disaster, and reduce personnel casualties and property loss.Lattice Boltzmann method is a new numerical simulation method. Based on lattice Boltzmann method, combined with knowledge of fluid mechanics and thermodynamics, the paper mainly researches on laws of flowing for high-temperature airflow during a fire disaster in underground tunnels. Firstly, an approach for simulating airflow flowing based on the double distributed velocity-temperature lattice Boltzmann model using by the method of block coupling is proposed. It objectively reflects the impact of depression of fire on the ventilating system. Secondly, combined with Boussinesq approximation and the improvement of dynamic viscosity, the paper proposes an improved model which increasing the internal coupling of the double distributed function to carry out simulated research on reversal development of lateral branch airflow which is one of main turbulence form in mine fire. Finally, based on the theory of double diffusive and three-dimensional lattice, a three-dimensional lattice Boltzmann model is proposed. The model increases the concentration field, and established the links with the velocity field and temperature field. Then it simulates research on rollback development of fire smoke which is another main turbulence form in mine fire.In mine fire period, the movement of high-temperature flow is a process of unsteady flowing, heat transferring and mass transferring in fire tunnel. In order to master laws of flowing for high-temperature airflow during a fire disaster in underground tunnels, the paper proposes more than one lattice Boltzmann models which simulate research on impact of depression, reversal development of lateral branch airflow and rollback development of fire smoke. During simulation, the fire is set up in a tunnel. A airflow flowing model is applied to study the laws of spreading. The simulating result shows that a great deal of information about velocity, temperature, concentration and pressure of airflow can be obtained and visual information about state of airflow along tunnels can also obtained, which provide a scientific basis to guide working of detection, prevention and cure in early fire period.