Results 31 to 40 of about 36,432 (262)

Source of Noise in Fans [PDF]

open access: yesThe Journal of the Acoustical Society of America, 1959
Many of the phenomena of noise of fans can be predicted from the simple assumption that the source of noise power is a pressure pulse created by the motion of the blade or impellor. From this assumption the well known fan sound laws can be derived: (1) the sound power varies as the fifth power of the blade tip speed, and (2) the sound power is ...
openaire   +1 more source

Noise-Source Identification for Ducted Fan Systems [PDF]

open access: yesAIAA Journal, 2007
Coherence-based source analysis techniques can be used to identify the contribution of combustion noise in the exhaust of a jet engine and to hence enable the design of noise-reduction devices. However, when the combustion noise propagates in a nonlinear fashion, the identified contribution using ordinary coherence methods will be inaccurate.
BENNETT, GARETH, FITZPATRICK, JOHN AIDAN
openaire   +3 more sources

Utjecaj radijalnog i aksijalnog razrmaka na emitiranu buku i performance ventilatora

open access: yesPromet (Zagreb), 2012
Among all auxilimy units of the air cooled diesel engine acooling fan is the noisiest. One of the noise generation mechanismsis the blade interaction with the vortices occurring in theradial and axial clearances of the fan due to the pressure ...
Mirko Čudina
doaj   +1 more source

Structural and biochemical analysis of a B12 superbinder

open access: yesFEBS Letters, EarlyView.
BtuG proteins are vitamin B12 scavengers in Bacteroides thetaiotaomicron, a dominant human gut bacterium. We present crystal structures of three BtuG homologs bound to cobalamin and its precursor cobinamide, revealing picomolar binding affinities, among the highest known for any natural protein.
Jose M. Martinez Felices   +3 more
wiley   +1 more source

Aerodynamic noise characteristics of a centrifugal fan in high-altitude environments.

open access: yesPLoS ONE
In high-altitude areas, the air is thin and the atmospheric pressure is low, which can affect the performance of centrifugal fans and aerodynamic noise.
Xue Liu, Jian Liu
doaj   +1 more source

Application of Wake Characteristics to Prediction of Broadband Noise of a Multiblade Fan

open access: yesJournal of Fluid Science and Technology, 2008
In this study, the wake characteristics of an arc blade were measured by the wind tunnel experiment; the characteristics were defined as the width of the wake, diameter of the vortex, ratio of the vortex scale, and the local lift.
Soichi SASAKI, Hidechito HAYASHI
doaj   +1 more source

Directed evolution of enzymes at the crossroads of tradition and innovation

open access: yesFEBS Open Bio, EarlyView.
An iterative cycle of data‐driven enzyme optimization comprising four stages: genetic diversification of a template enzyme, expression of protein variants, high‐throughput evaluation, and machine‐learning‐guided redesign of the next variant library.
Maria Tomkova   +2 more
wiley   +1 more source

Impact of the turbulence modeling approach on the accuracy of the fan noise level prediction

open access: yesВестник Самарского университета: Аэрокосмическая техника, технологии и машиностроение, 2018
The fan is the dominant source of noise for modern high bypass ratio aircraft engines. The article presents the results of investigating the influence of the approach to modeling the turbulence in modeling fan stage noise generation on the results of ...
K. R. Pyatunin, N. V. Arkharova
doaj   +1 more source

Numerical Investigation of Unsteady Flow and Aerodynamic Noise Characteristics of an Automotive Axial Cooling Fan

open access: yesApplied Sciences, 2020
Low-speed axial cooling fans are frequently used to manage engine temperature by ensuring that adequate quantities of air pass through heat exchangers, even at low vehicle speeds or in the idle condition. This study aims to provide a better understanding
Jang-oh Mo, Jae-hyuk Choi
doaj   +1 more source

Structural studies and functional engineering of NanX: an anhydro‐sialic acid transporter from Escherichia coli

open access: yesFEBS Open Bio, EarlyView.
Biophysical characterisation shows that NanX, a membrane transport protein from the major facilitator superfamily (MFS), forms both monomers and dimers after purification. AlphaFold modelling and substrate docking provide information on residues likely involved in substrate recognition for NanX and another MFS member, NanT.
Michael C. Newton‐Vesty   +13 more
wiley   +1 more source

Home - About - Disclaimer - Privacy