Noise Sources and Room Acoustics of Closed Circuit Subsonic Wind Tunnels

1973 ◽  
Vol 53 (1) ◽  
pp. 370-370
Author(s):  
I. L. Vér
Keyword(s):  
Closed Circuit ◽  
Wind Tunnels ◽  
Room Acoustics ◽  
Noise Sources

The Dust Problem in Hot-Wire Anemometry

1954 ◽  
Vol 4 (1) ◽  
pp. 93-102 ◽  
Author(s):  
D. C. Collis
Keyword(s):  
Wind Tunnel ◽  
Experimental Work ◽  
Fluid Motion ◽  
Rate Of Change ◽  
Closed Circuit ◽  
Wind Tunnels ◽  
Hot Wire ◽  
Hot Wire Anemometry ◽  
Hot Wires ◽  
The Wire

SummaryExperimental work is described showing that a major cause of changes in the calibrations of hot-wire anemometers consists in the precipitation of dust on the upstream surface of the wire during use. A simple means of cleaning the air in closed-circuit wind tunnels is described. The rate of change of calibration due to dust was reduced in the Manchester University Fluid Motion Laboratory by at least a factor of 15, by adequate cleaning of the air and by minimising the amount of interchange between the tunnel air and the atmosphere. It is concluded that where accurate results are required from hot wires used in a wind tunnel, the tunnel should be designed to be dust-free.

scholarly journals Noise Source Identification in Training Facilities and Gyms

2021 ◽  
Vol 12 (1) ◽  
pp. 54
Author(s):  
Jakub Wróbel ◽  
Damian Pietrusiak
Keyword(s):  
Noise Reduction ◽  
Vibration Isolation ◽  
Room Acoustics ◽  
Noise Sources ◽  
Adaptation Measures ◽  
Acoustic Environment ◽  
Acoustic Adaptation ◽  
Industrial Sites ◽  
Noise Source Identification

This paper deals with noise problems in industrial sites adapted for commercial training venues. The room acoustics of such an object were analyzed in the scope of the reverberation time and potential acoustic adaptation measures are indicated. Identification and classification of noise sources in training facilities and gyms was carried out based on the acoustic measurements. The influence of rubber padding on impact and noise reduction was investigated in the case of chosen noise-intensive exercise activities performed in a previously described acoustic environment. Potential noise reduction measures are proposed in the form of excitation reduction, vibration isolation, and room acoustics adaptation.

Speed control of large wind tunnels

1958 ◽  
Vol 4 (39) ◽  
pp. 146-147
Author(s):  
L.S. Drake ◽  
J.A. Fox ◽  
G.H.A. Gunnell
Keyword(s):  
Speed Control ◽  
Wind Tunnels ◽  
Large Wind

Scaling risk assessment in a closed circuit recycled board mill by speciation methods

TAPPI Journal ◽  
2012 ◽  
Vol 11 (5) ◽  
pp. 53-61 ◽  
Author(s):  
PATRICK HUBER ◽  
SYLVIE NIVELON ◽  
PATRICE NORTIER
Keyword(s):  
Calcium Carbonate ◽  
Volatile Fatty Acids ◽  
Inorganic Carbon ◽  
Stability Index ◽  
Closed Circuit ◽  
Critical Problem ◽  
Local Scaling ◽  
Water Analyses ◽  
Closed Water ◽  
Speciation Calculation

Calcium carbonate scaling often is a critical problem for recycled board mills that have closed water circuits. The objective of this study was to determine local scaling risks throughout the production process. To predict scaling potential, we calculated several saturation indexes, based on speciation determined from detailed water analyses. Calculated scaling trends are in accordance with observed dissolution and precipitation of calcium carbonate in the process, when considering local aeration phenomena. The importance of volatile fatty acids (resulting from anaerobic bacterial activity) in calco-carbonic equilibriums is discussed, and taken into account in the speciation calculation. We also demonstrate the need to measure inorganic carbon instead of alkalinity in such conditions. This makes typical scaling indexes, such as the Ryznar Stability Index, irrelevant to predict scaling risk in closed circuit conditions; thus, it is necessary to use general speciation methods, as described in this paper.

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