Numerical modelling of unsteady turbulent flow in smooth-walled pipes

D Nigel Johnston

OAI: oai:purehost.bath.ac.uk:publications/23640c95-8550-4ad6-8ce5-807c4535ae95 • DOI: https://doi.org/10.1177/0954406211400796

An efficient numerical model for turbulent friction has been developed for smooth-walled pipe flow. The aim was to develop a new approach to the numerical modelling, eliminating some important approximations and sources of error, such that the method can be applied reliably under a wide range of conditions. A simple two-region model of effective viscosity is used. For short timescales the turbulence level and effective viscosity distribution are ‘frozen’ in time. The velocity profile is determined numerically for a range of frequencies and viscosity distributions, and this is used to determine the frequency-dependent friction. This is then approximated using simple weighing functions.