Description
Tunnel design requires rapid estimation of variations in the maximum pressure gradient of compression waves, particularly for micro-pressure waves, in high-speed railway tunnels. However, achieving such rapid estimates poses significant challenges. This study proposed an approximate equation for estimating the maximum pressure gradient based on the Padé approximation. The Padé approximation agrees well with the simulation results obtained from one-dimensional computational fluid dynamics (1D CFD). Moreover, in contrast to 1D CFD, the Padé approximation required fewer calculations per step, making it feasible to solve using Microsoft Excel. Thus, the Padé approximation can decrease the calculation time to 1/(100 𝑁𝑁2), where N is the number of grid points in 1D CFD.
