In applications, the acoustics of fans can differ significantly from measurements standalone fan. This is due to disturbed inflow conditions, for example, caused by a heat exchanger upstream an axial Resolving complex geometry and dimensions typical exchangers in aeroacoustic scale-resolving simulations leads very high computation effort, which currently not economically feasible. Turbulence re...

background : the application of ventilation systems in industries and workplaces is with the aim of improving environmental conditions for employees. the lack of appropriate ventilation system components design and control methods result in the production of sound and vibration in most components. the purpose of this study was to determine the role of the pad isolator in controlling vibration a...

Somites, paired epithelial spheres on either side of the axial neural tube and notochord, form by condensation of the segmental plate mesoderm at its cranial end, producing, in the case of chick, 50 somite pairs at a rate of one somite every 90 minutes (Palmeirim et al., 1997). The sequential formation of somites in a caudo-cranial direction imparts a progressive cranial directed maturation gra...

In This paper, a parametric study of compressor performances was performed by streamline curvature method (SLC). Effects of three input parameters in design process, e.g., number of blades, distribution of blade thickness, and blade sweep angels, on the main objective parameters in aerodynamic design, e.g., velocity distribution, efficiency and pressure ratio, has been investigated in the param...

One of the main noise sources in computers are the cooling fans. Tonal noise at the rotational frequency of the fan, the blade passing frequency (BPF) and its higher harmonics are important in fan noise. So called 'side-resonators' integrated in the duct of an in-duct axial fan cause an impedance change in the duct and, having proper dimensions and correct position, act as an acoustic mirror re...

The increased performance of close series stacked tube axial fans due to the introduction of a diffuser element between the primary and secondary fan is investigated in this paper. Experimental results showed that there was a 15% increase on average in the performance of two stacked Delta FFB0412VHN 40 mm fans across their operating range when a diffuser element was introduced between the two f...

Coherence based source analysis techniques can be used to identify the contribution of broadband noise sources in the exhaust of a gas turbine and hence enable the design of noise reduction devices. However, when the broadband noise source propagates in a non-linear fashion the identified contribution using ordinary coherence methods will be inaccurate. In this paper, an analysis technique to e...