Fast Meshless Solution with Lumped Friction for Laminar Fluid Transients

Fluid transients without friction in pipelines can be solved by a time-domain exact solution, using a simple recursive process without computational grid. But the calculation time cost of this approach is very high because of the recursion algorithm. Its improved method, named as the fast meshless solution (FMS), was developed to speed the computation by introducing the time-line interpolation. However, when the friction is considered, the conventional distributed friction model cannot be employed directly for the FMS is meshless. To address this problem, the fluid friction is lumped at pipe ends, and both steady and unsteady laminar flow are investigated. Three kinds of lumped models are proposed here, and compared with a numerical case of the water hammer. The laminar fluid transients can be calculated fast by the present method, with a little reduced accuracy. This method may be of interest in a quick assessment of the piping fluid transients.