Empirical study on a coefficient of discharge μ from the flexible ducts

Abstract The paper discusses issues connected with a coefficient of discharge μ and elements which provide a fluid flow regulation. The measurements were carried out for a few flexible conduits which differed in a perforation extent but had the same size (diameter and length). The outlets were located equally along the length of the pipe – the first one was 1.0 m from the place where the duct was attached to the hopper, while the last outlet was 1.0 m from the end of conduit. The outlets in each test had different diameters and were located in three distances. The results from 13 series of measurements showed that the coefficient of discharge was in range μ  = 0.96–0.99, so it differed significantly from values recommended for the stiff conduits.

[1]  Svend Svendsen,et al.  Experimental study of perforated suspended ceilings as diffuse ventilation air inlets , 2013 .

[2]  M. Sulewska.  The Control of Soil Compaction Degree by Means of LFWD , 2012 .

[3]  Hao Peng,et al.  Field synergy analysis on convective heat transfer and fluid flow of a novel triangular perforated fin , 2013 .

[4]  Md. Tariqul Islam,et al.  Heat transfer and friction factor characteristics in turbulent flow through a tube fitted with perforated twisted tape inserts , 2013 .

[5]  B. J. Bailey.  Fluid Flow in Perforated Pipes , 1975 .

[6]  Yiu-Yin Lee,et al.  Widening the sound absorption bandwidths of flexible micro-perforated curved absorbers using structural and acoustic resonances , 2007 .

[7]  E. Brundrett.  Prediction of airflow with swirl in perforated polyethylene tubes , 1990 .

[8]  Jaehoon Seong,et al.  Comparison of effects on technical variances of computational fluid dynamics (CFD) software based on finite element and finite volume methods , 2014 .

[9]  A. Pagano,et al.  On the pressure losses through perforated plates , 2012 .

[10]  Y. Çengel,et al.  Thermodynamics : An Engineering Approach , 1989 .

[11]  C. P. Stephens,et al.  Behavior of polyethylene in a variable temperature density gradient column , 2013 .

[12]  Andrzej Gajewski,et al.  Measurement of velocity distribution for air flow through perforated plastic foil ducts , 2011 .

[13]  K. El Moueddeb,et al.  Perforated Ventilation Ducts: Part 1, A Model for Air Flow Distribution , 1997 .