Spatially varied flow impact on resistance in corrugated pipes

Abstract

The roughness coefficient is a significant factor in hydraulic design process, but carries vast uncertainty in practice. This paper reports the resistance coefficients of corrugated PVC pipes under different flow regimes (i.e. pressurised, gradually varied flow (GVF) and spatially varied flow (SVF) with increasing discharge). The investigated corrugated pipes are mainly used in subsurface drainage systems and carry a SVF. The influence of SVF on the roughness coefficient of such pipes has not yet been reported. The pipes were first examined to determine the roughness coefficient for pressurised flow. The influence of GVF and SVF was then studied. The results show that pipes behave differently in different flow regimes and the impacts of each flow condition on the flow resistance are reported here.

Editorial

“…Our first contribution focuses on varying roughness coefficients attributable to different flow regimes in corrugated PVC pipes (Kouchakzadeh et al, 2011). Such pipes are commonly used in sewer and subsurface drainage networks and understanding different roughness conditions under increasing discharge in gradually varied, spatially varied and pressurised flow is important in estimating the discharge capacity of the pipe network.…”