Fan Flow Control for Noise Reduction Part 3: Rig Testing of Optimal Design

Langford, Matthew; Minton, Christopher M.; Ng, Wing F.; Burdisso, Ricardo A.; Halasz, Christopher

doi:10.2514/6.2005-3027

Cited by 7 publications

(2 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Three detailed studies of TEB as a RSI noise reduction technique were performed by Halasz et al [17] and Langford et al [18] [19] from the Virginia Tech. The first study aimed at an advanced TEB concept to reduce the amount of injected mass flow using an alternating TEB design where the blowing mass flow is guided into selected fan blades.…”

Section: Fig 4 Teb Blade Design Of Sutliff Et Al [3]mentioning

confidence: 99%

Active Control of Fan Tones by means of Trailing Edge Blowing

Enghardt

Kausche

Moreau

2015

21st AIAA/CEAS Aeroacoustics Conference

View full text Add to dashboard Cite

At DLR in Berlin, a series of experiments was performed on a laboratory scale fan rig to explore the potential of trailing edge blowing (TEB) for the attenuation of tonal noise of an axial fan stage. The model fan consisted of 18 blades, each of which was equipped with five internal flow channels, commonly provided with pressurized air through the rotor hub. In configuration 1, all five channels were utilized for noise control. In configuration 2, the outmost two internal channels were blocked by means of aluminum tape. The latter case provided substantial tonal noise reduction, whereas the former led to no acoustic impact. In order to reproduce the experimental result, an analytical acoustic model based on the flow field measured by the hot wires was utilized. The model considers the interaction of the rotor wakes with the stator and substitutes the real sources by a spatial distribution of dipoles on the blades. Thus, the impact of the trailing edge blowing is modelled via the wake velocity perturbations and the unsteady lift they induce on the stator blades. The predicted noise reductions achieved by the TEB approach are in fairly good agreement with the experiments. Moreover, the model provides helpful indications about the reason for the failure of conf. 1 to provide a noise reduction and the success of conf. 2 to do so.

show abstract

Section: Fig 4 Teb Blade Design Of Sutliff Et Al [3]mentioning

confidence: 99%

Active Control of Fan Tones by means of Trailing Edge Blowing

Enghardt

Kausche

Moreau

2015

21st AIAA/CEAS Aeroacoustics Conference

View full text Add to dashboard Cite

show abstract

“…for stators with V equally spaced vanes (5) q = q for stators with V irregularly spaced vanes (6) p( ,t) = c mn cos m n + mn m q + nB q (8) Recognizing that the first exponential term does not vary with q, we can define the relations:…”

Section: Th Harmonic Of the Blade Passing Frequency (Bpf) For This Tementioning

confidence: 99%