Home > Error Analysis > Error Analysis Of Two-microphone Measurements In Ducts With Flow

Error Analysis Of Two-microphone Measurements In Ducts With Flow

In Ref. 5, it is assumed that the signal is periodic; in that case, Eqs. (8) and (9) can be used directly. Muffler designers need simple and fast modeling tools, especially in the preliminary design evaluation stages. Am., Vol. 83, No. 6, June 1988 M. ,•bom and H. The errors in the remaining parts depend on the errors in a measured autospectrum and Mach number. navigate to this website

The condition for this is exp [ 2iks/ ( 1 -- M 2) ] • 1, where k = 2rrf/c, which is equivalent to ks/ (1 - M 2) •rrn, n In the present work, we have also tried to give a short review of the different types of two-micro- phone methods that have been presented in the literature. If you are logged in, you won't see ads. in Eqs. (8) and (9) should be interpreted as the finite Four- ier transform.

Am., Vol. 83, No. 6, June 1988 M. The influence of errors on the calculated quantities was investigated. P.

Abom and H. Finally, a new technique for measuring the Mach number using a two-microphone method is suggested. Sometimes a non-reflecting horn with sound absorbing materials is used at the open end in order to realize non-reflecting condition. As shown in Ref. 16, this property can be used to reduce the influence of flow noise disturbances.

ArenasRead full-textMusical sound synthesis and a new music representation based on empirical physical modeling of musical instruments[Show abstract] [Hide abstract] ABSTRACT: Thesis (Ph. Therefore, the final result can also be used to study the influence of errors other than length errors. In addition, the measurement point 1 (see Fig. 4), should be positioned as close as possible to the muffler, although a minimum distance of about 10 mm should be considered in Also, the remainder of the discussion of errors in the transfer function estimate is still, in its general terms, applicable.

Many of the results obtained for the no flow case are also applicable for the case with flow. Theory," J. Ross, "Experimental determination of acoustic properties using a two-microphone random-excitation technique," J. Bod•n and M..•bom, "Influence of errors on the two-microphone method for measuring acoustic properties in ducts," J.

Equation (20) also implies that, at the frequencies corre- sponding to ks/( 1 -M 2) = (2n + 1 )•r/2, the normalized bias error is given by E[H '12 ] = Soc. The analysis of selected frequency bands successfully shows how different, known noise phenomena of particular interest such as mid-frequency “whoosh noise” and low-frequency surge onset are correlated with operating conditions of F.

A. http://axishost.net/error-analysis/error-analysis-immunochemistry-error-analysis.php The method they analyze is based on a transfer function approach, simi- lar to that suggested by Chung and Blaser, 3 and the medium is assumed to be at rest. Sign in via Shibboleth/Athens Register My Cart Export citations BibTEX Endnote Plain Text RefWorks Add to my favorites Recommend to library /recommendto/form;jsessionid=j8jHBg_XppKXax8Wlhd_9Xow.x-aip-live-03?webId=%2Fcontent%2Fasa%2Fjournal%2Fjasa&title=The+Journal+of+the+Acoustical+Society+of+America&issn=0001-4966 The Journal of the Acoustical Society of America — Yano, and H.

Acoust. The influence of errors on the calculated quantities has been investigated and the conclusions from the earlier work have been extended to the case with flow. L. http://axishost.net/error-analysis/error-analysis-techniques-for-planar-near-field-measurements.php To solve this problem, we have chosen a type of least-squares proce- dure.

GergesR. All rights reserved.About us · Contact us · Careers · Developers · News · Help Center · Privacy · Terms · Copyright | Advertising · Recruiting We use cookies to give you the best possible experience on ResearchGate. The errors in the measured input data are then analyzed and special attention is paid to the effects of neglected attenuation, nonideal microphones, and flownoise.

Let us now turn to the error caused by the finite micro- phone input impedance.

YanRead full-textInfluence of errors on the two-microphone method for measuring acoustic properties in ducts Full-text · Article · Feb 1986 Hans BodénMats ÅbomRead full-textData provided are for informational purposes only. When the attenuation be- tween the microphones is not negligible, then either we have to use at least three microphones or, as suggested in Refs. 2, 5, and 8, use a Dept. This ad- vantage is that the acoustic quantity of interest is estimated as the optimum linear relationship between an input and out- put quantity.

Chinese Physical Society Laser Institute of America The Society of Rheology » View All Publishers Publications Topics Collections | Librarians Authors My Cart Home > Publishers > Acoustical Society of America Please log in to see this content. For a calculated quanti- ty of the second type, the error will not only depend on R t. get redirected here Acoust.

Box 11282-Elkoba, Cairo, EgyptAmerican Journal of Vehicle Design. 2015, Vol. 3 No. 1, 16-26DOI: 10.12691/ajvd-3-1-3Copyright © 2015 Science and Education PublishingCite this paper: Sabry Allam. Sound Vib. 107, 355-358 (1986). 2øS. I )/(l q-]•l), (30) b [H ;•.• ] = H,,,.2/5'2(1 - B *H,:v:• )/( 1 +/•2B *H,,,.,, ), (31) where/•l is the noise-to-signal ratio at microphone 1, •2 is the noise-to-signal Differing provisions from the publisher's actual policy or licence agreement may be applicable.This publication is from a journal that may support self archiving.Learn moreLast Updated: 17 Jul 16 © 2008-2016 researchgate.net.

Recent advances in modeling procedures for accurate performance prediction have led to the development of modeling methods for practical muffler components in commercial design. See all ›66 CitationsSee all ›30 ReferencesShare Facebook Twitter Google+ LinkedIn Reddit Request full-text Error analysis of two-microphone measurements in ducts with flowArticle · January 1988 with 25 Reads1st Mats Abom32.03 · KTH Royal Institute Hover to learn more.Academia.edu is experimenting with adspptxError analysis of two-microphone measurements in ducts with flow1 PagesError analysis of two-microphone measurements in ducts with flowUploaded byAbom AbomFiles1of 2statistiques.pptxlink.aip.org/link/JASM...Viewsconnect to downloadGetpptxREAD PAPERError Am. 68, 907-913 (1980); also, "Transfer function method of measuring in-duct acoustic properties, II.

This means that, when Eq. (19) is applied to condenser microphones, it will overestimate the bias error. Using both flame images and measured flame transfer functions (FTFs), the effect of confinement is investigated and generalized across a broad range of operating conditions. Article copyright remains as specified within the article. The influence of errors on the calculated quantities has been investigated and the conclusions from the earlier work have been extended to the case with flow.

R.