On the prediction of uniformity of air flow out from manifold distribution

Abstract

AbstractComputational fluid dynamics (CFD) was used to simulate a closed‐end multiple outlet pipe to examine the effect of different exit port geometry and size of perforation on performance of manifold distribution. To obtain an optimum design, the amount of fluid discharging from any opening in a pipe is greatly concern in engineering applications because uniform flow distribution has significant influence on the performance of manifold distribution. In this investigation, the vertical manifold system was used to study the hydrodynamics of air flow and simulate with computational fluid dynamics (CFD). Firstly, three different exit port geometry (circular, rectangular and square) are chosen to investigate the effect of exit port on mass flow rate uniformity effusing from distribution manifold. The best performance, which most closely approximating uniform outflow was achieved by the rectangle exit ports. Secondly, three different perforation size (3, 4 and 5 mm) of circular exit port were selected to reach to the finding of uniformity. Results show the 5 mm diameter orifices exit port achieve the uniform outflow of all. The ratio of the total opening area for all cases to the cross‐sectional area of the cylindrical pipe is identical for these two cases. Thirdly, the effect of perforation diameter with variable pipe ratio for equal number of orifices was investigated. The analysis for investigating the changes in the discharge angle of the stream between the orifices of multi‐perforated pipes perform for all cases. Standard k–ϵ turbulence model was considered for the numerical simulation, the finding results of numerical simulation were evaluated by the laboratory experiments.