The sources of jet noise: experimental evidence

Experimental acoustic identification of flow noise sources in expansion chambers

For the aeroacoustic design of expansion chambers, commonly installed in e.g. HVAC ducts or automotive exhaust systems, the aerodynamic noise generation mechanisms as well as the transmission characteristics of acoustic waves propagating in a non-quiescent medium have to be taken into account. The attenuation of downstream propagating acoustic waves should be maximized with a minimum of additio...

Numerical study on the acoustic field of a centrifugal fan and the tonal noise sources

The widespread use of squirrel cage fans, especially in ventilation and home and industrial environments, has led to the formation of many research efforts to improve performance and reduce the sound produced by this type of fan. In the literature, the most important factor in generating sound in this category of fans is the confrontation between the rotor exit flow and the volute of the fan. I...

Experimental Studies of Inverted - Profile Coaxial Jet Flows

Experimental and CFD Studies on the Effect of the Jet Position on Mixing Performance

Understanding jet noise.

Jets are one of the most fascinating topics in fluid mechanics. For aeronautics, turbulent jet-noise modelling is particularly challenging, not only because of the poor understanding of high Reynolds number turbulence, but also because of the extremely low acoustic efficiency of high-speed jets. Turbulent jet-noise models starting from the classical Lighthill acoustic analogy to state-of-the ar...