Multiscale modeling of shock wave propagation induced by coal and gas outbursts

We explore the propagation modes of shock waves driven by coal and gas outbursts in both the near- and far-field. Near-field response is three-dimensional (3D) at the face, but the far-field is constrained to one-dimensional (1D) flow within the roadways. Fluent models are applied to simulate the 3D propagation of shock waves at the outburst source with 1D models utilizing Flowmaster being sufficient distal from the face. These models are linked via a Mesh-based parallel Code Coupling Interface (MPCCI) to define shock wave propagation at all scales – from mine face to distal roadways. The results demonstrate the suitability and fidelity of the Flowmaster 1D simulation in representing the time history of overpressure. The shock wave attenuation in each part of the MPCCI coupled model is consistent with experimental results. This work provides a logical, consistent and robust method to solve for the complex coupling at multiple length- and time-scales and its implementation as an “outburst” pipe network. Additionally, it has significant utility in designing for outburst mitigation, disaster ventilation and other safety measures.