Abstract:
Computational Fluid Dynamics (CFD) based simulation procedures are considered to be
an indispensable analysis and design tool in a wide and ever-increasing range of
applications involving fluid flow. This work presents computational investigation of
turbulent flow inside pipes of varying diameters. A computational fluid dynamics model
of turbulent flow in the pipes is implemented with the help of ANSYS FLUENT 6.3.26
software. Two Reynolds Averaged Navier Stokes Turbulent models; the
k
and
k
models are used for the simulation and the variation of axial velocity, skin friction
coefficient and turbulent intensity along the length of the pipes is analyzed. The viscous
boundary layer is expected to grow along the pipe starting at the inlet. It will eventually
grow to fill the pipe completely (provided that the pipe is long enough). When this
happens, the flow becomes fully-developed and there is no variation of the velocity profile
in the axial direction. A closed-form solution to the governing equations can be obtained
in the fully-developed region. The fluid used for this purpose is air and the pipe material is
aluminium. The Reynold’s number is based on the pipe diameter and average velocity at
the inlet and is taken as 10,000 for fully turbulent flow. The numerical results obtained
from two models are compared with each other and validated against experimental data
from the literature. Between the two models, the k-epsilon model was found to give better
results.
