Forchheimer flow to a well considering time-dependent critical radius Academic Article uri icon

abstract

  • Abstract. Previous studies on the non-Darcian flow into a pumping well assumed that critical radius (RCD) was a constant or infinity, where RCD represents the location of the interface between the non-Darcian flow region and Darcian flow region. In this study, a two-region model considering time-dependent RCD was established, where the non-Darcian flow was described by the Forchheimer equation. A new iteration method was proposed to estimate RCD based on the finite-difference method. The results showed that RCD increased with time until reaching the quasi-steady state flow, and the asymptotic value of RCD only depended on the critical specific discharge beyond which flow became non-Darcian. A larger inertial force would reduce the change rate of RCD with time, and resulted in a smaller RCD at a specific time during the transient flow. The difference between the new solution and previous solutions were obvious in the early pumping stage. The new solution agreed very well with the solution of previous two-region model with a constant RCD under quasi-steady flow. It agreed with the solution of the fully Darcian flow model in the Darcian flow region, and with the solution of the fully non-Darcian flow model in the non-Darcian flow region near the well.

author list (cited authors)

  • Wang, Q., Zhan, H., & Tang, Z.

citation count

  • 1

complete list of authors

  • Wang, Q||Zhan, H||Tang, Z

publication date

  • November 2013