Some measurements in the self-preserving jet
The axisymmetric turbulent incompressible and isothermal jet was investigated by use of linearized constant-temperature hot-wire anemometers. It was established that the jet was truly self-preserving some 70 diameters downstream of the nozzle and most of the measurements were made in excess of this...
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Language: | English |
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Cambridge University Press (CUP)
1969
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Online Access: | http://dx.doi.org/10.1017/s0022112069000358 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022112069000358 |
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crcambridgeupr:10.1017/s0022112069000358 2024-09-30T14:42:32+00:00 Some measurements in the self-preserving jet Wygnanski, I. Fiedler, H. 1969 http://dx.doi.org/10.1017/s0022112069000358 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022112069000358 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Journal of Fluid Mechanics volume 38, issue 3, page 577-612 ISSN 0022-1120 1469-7645 journal-article 1969 crcambridgeupr https://doi.org/10.1017/s0022112069000358 2024-09-11T04:03:28Z The axisymmetric turbulent incompressible and isothermal jet was investigated by use of linearized constant-temperature hot-wire anemometers. It was established that the jet was truly self-preserving some 70 diameters downstream of the nozzle and most of the measurements were made in excess of this distance. The quantities measured include mean velocity, turbulence stresses, intermittency, skewness and flatness factors, correlations, scales, low-frequency spectra and convection velocity. The r.m.s. values of the various velocity fluctuations differ from those measured previously as a result of lack of self-preservation and insufficient frequency range in the instrumentation of the previous investigations. It appears that Taylor's hypothesis is not applicable to this flow, but the use of convection velocity of the appropriate scale for the transformation from temporal to spatial quantities appears appropriate. The energy balance was calculated from the various measured quantities and the result is quite different from the recent measurements of Sami (1967), which were obtained twenty diameters downstream from the nozzle. In light of these measurements some previous hypotheses about the turbulent structure and the transport phenomena are discussed. Some of the quantities were obtained by two or more different methods, and their relative merits and accuracy are assessed. Article in Journal/Newspaper sami Cambridge University Press Nozzle ENVELOPE(159.100,159.100,-79.917,-79.917) The Nozzle ENVELOPE(159.100,159.100,-79.917,-79.917) Journal of Fluid Mechanics 38 3 577 612 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
description |
The axisymmetric turbulent incompressible and isothermal jet was investigated by use of linearized constant-temperature hot-wire anemometers. It was established that the jet was truly self-preserving some 70 diameters downstream of the nozzle and most of the measurements were made in excess of this distance. The quantities measured include mean velocity, turbulence stresses, intermittency, skewness and flatness factors, correlations, scales, low-frequency spectra and convection velocity. The r.m.s. values of the various velocity fluctuations differ from those measured previously as a result of lack of self-preservation and insufficient frequency range in the instrumentation of the previous investigations. It appears that Taylor's hypothesis is not applicable to this flow, but the use of convection velocity of the appropriate scale for the transformation from temporal to spatial quantities appears appropriate. The energy balance was calculated from the various measured quantities and the result is quite different from the recent measurements of Sami (1967), which were obtained twenty diameters downstream from the nozzle. In light of these measurements some previous hypotheses about the turbulent structure and the transport phenomena are discussed. Some of the quantities were obtained by two or more different methods, and their relative merits and accuracy are assessed. |
format |
Article in Journal/Newspaper |
author |
Wygnanski, I. Fiedler, H. |
spellingShingle |
Wygnanski, I. Fiedler, H. Some measurements in the self-preserving jet |
author_facet |
Wygnanski, I. Fiedler, H. |
author_sort |
Wygnanski, I. |
title |
Some measurements in the self-preserving jet |
title_short |
Some measurements in the self-preserving jet |
title_full |
Some measurements in the self-preserving jet |
title_fullStr |
Some measurements in the self-preserving jet |
title_full_unstemmed |
Some measurements in the self-preserving jet |
title_sort |
some measurements in the self-preserving jet |
publisher |
Cambridge University Press (CUP) |
publishDate |
1969 |
url |
http://dx.doi.org/10.1017/s0022112069000358 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022112069000358 |
long_lat |
ENVELOPE(159.100,159.100,-79.917,-79.917) ENVELOPE(159.100,159.100,-79.917,-79.917) |
geographic |
Nozzle The Nozzle |
geographic_facet |
Nozzle The Nozzle |
genre |
sami |
genre_facet |
sami |
op_source |
Journal of Fluid Mechanics volume 38, issue 3, page 577-612 ISSN 0022-1120 1469-7645 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s0022112069000358 |
container_title |
Journal of Fluid Mechanics |
container_volume |
38 |
container_issue |
3 |
container_start_page |
577 |
op_container_end_page |
612 |
_version_ |
1811644537773228032 |