Computation of air entrainment into a mixing pipe: An experimental and numerical analysis / Dipti Prasad Mishra and Subhash Chandra Paramanik

Computations of entrainment of air into a pipe were performed by placing an
air jet at the bottom of the pipe. An experiment was performed with
cylindrical mixing pipe having different diameter, length and jet location. A
flow meter was used to measure the flow through the nozzle and velocity at
the mixing pipe exit was measured by anemometer. CFD analyses were
performed using Ansys-Fluent 16 to match the experimental results for exit
velocity and amount of air sucked into the pipe. Further numerical
investigations were performed for a mixing pipe with hot jet to estimate the
amount of air entrained as a function pipe diameter, pipe length, nozzle
protrusion and pipe shape. It was found from the numerical simulations there
exists an optimum pipe length and nozzle protrusion for highest entrainment
of air. Also a particular frustum shaped pipe could suck highest air
compared to cylindrical shaped pipe.