Study of the Hydrodynamic Unsteady Flow Inside a Centrifugal Fan and Its Downstream Pipe Using Detached Eddy Simulation

The detailed unsteady turbulent flow inside a centrifugal fan and its downstream pipe was studied using detached eddy simulation (DES) at three flowrates, namely, the best efficiency point (BEP), 0.75BEP, 1.49BEP. Both mean fluctuating fields were analyzed on basis of root-mean-square value as indication intensity. Results showed that pressure fluctuation had minimum BEP, but velocity increased with flowrate. Most regions underwent large magnitude about 10~20% pref = 0.5 ?u22, where u2 is blade impeller outlet. maximum side tongue tip rather than stagnation point, it decreased rapidly along outlet 1% after distance five diameters. spectra hydrodynamic conspicuous spikes passing frequency (BPF) in volute not pipe. At entrance, agreed experimental results, showing fluctuations dominant; however, data much slower decreasing rate due to acoustic fluctuations.