Flow stability in a wide vaneless diffuser

This work is concerned with the theoretical aspects of flow stability in a two dimensional vaneless diffuser. Specifically, the appearance of self-excited oscillations, also referred to as rotating stall, is investigated considering a two-dimensional inviscid flow in an annulus. We consider a linear...

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Autores principales:	S. Guadagni, M. Giachi, L. Fusi, A. Farina
Formato:	article
Lenguaje:	EN
Publicado:	Elsevier 2020
Materias:	Centrifugal compressor Linear stability Stall curve Engineering (General). Civil engineering (General) TA1-2040
Acceso en línea:	https://doaj.org/article/1a6049183ba94b9cb1635007bcf8cc51
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id	oai:doaj.org-article:1a6049183ba94b9cb1635007bcf8cc51
record_format	dspace
spelling	oai:doaj.org-article:1a6049183ba94b9cb1635007bcf8cc512021-12-01T05:05:45ZFlow stability in a wide vaneless diffuser2666-496810.1016/j.apples.2020.100025https://doaj.org/article/1a6049183ba94b9cb1635007bcf8cc512020-12-01T00:00:00Zhttp://www.sciencedirect.com/science/article/pii/S266649682030025Xhttps://doaj.org/toc/2666-4968This work is concerned with the theoretical aspects of flow stability in a two dimensional vaneless diffuser. Specifically, the appearance of self-excited oscillations, also referred to as rotating stall, is investigated considering a two-dimensional inviscid flow in an annulus. We consider a linear perturbation method, taking as basic flow the steady potential velocity field whose radial and tangential components are inversely proportional to the radial coordinate. We show that such flow may become unstable to small two-dimensional perturbations provided that the ratio between the inlet tangential velocity and the radial one is sufficiently large and a certain amount of vorticity is injected in the flow field. Such an instability is purely kinematical, i.e. it does not involve any boundary layer effects, contrary to the classical hypothesis which ascribes the instability to a peculiar boundary layers interaction.S. GuadagniM. GiachiL. FusiA. FarinaElsevierarticleCentrifugal compressorLinear stabilityStall curveEngineering (General). Civil engineering (General)TA1-2040ENApplications in Engineering Science, Vol 4, Iss , Pp 100025- (2020)
institution	DOAJ
collection	DOAJ
language	EN
topic	Centrifugal compressor Linear stability Stall curve Engineering (General). Civil engineering (General) TA1-2040
spellingShingle	Centrifugal compressor Linear stability Stall curve Engineering (General). Civil engineering (General) TA1-2040 S. Guadagni M. Giachi L. Fusi A. Farina Flow stability in a wide vaneless diffuser
description	This work is concerned with the theoretical aspects of flow stability in a two dimensional vaneless diffuser. Specifically, the appearance of self-excited oscillations, also referred to as rotating stall, is investigated considering a two-dimensional inviscid flow in an annulus. We consider a linear perturbation method, taking as basic flow the steady potential velocity field whose radial and tangential components are inversely proportional to the radial coordinate. We show that such flow may become unstable to small two-dimensional perturbations provided that the ratio between the inlet tangential velocity and the radial one is sufficiently large and a certain amount of vorticity is injected in the flow field. Such an instability is purely kinematical, i.e. it does not involve any boundary layer effects, contrary to the classical hypothesis which ascribes the instability to a peculiar boundary layers interaction.
format	article
author	S. Guadagni M. Giachi L. Fusi A. Farina
author_facet	S. Guadagni M. Giachi L. Fusi A. Farina
author_sort	S. Guadagni
title	Flow stability in a wide vaneless diffuser
title_short	Flow stability in a wide vaneless diffuser
title_full	Flow stability in a wide vaneless diffuser
title_fullStr	Flow stability in a wide vaneless diffuser
title_full_unstemmed	Flow stability in a wide vaneless diffuser
title_sort	flow stability in a wide vaneless diffuser
publisher	Elsevier
publishDate	2020
url	https://doaj.org/article/1a6049183ba94b9cb1635007bcf8cc51
work_keys_str_mv	AT sguadagni flowstabilityinawidevanelessdiffuser AT mgiachi flowstabilityinawidevanelessdiffuser AT lfusi flowstabilityinawidevanelessdiffuser AT afarina flowstabilityinawidevanelessdiffuser
_version_	1718405525804154880

Flow stability in a wide vaneless diffuser

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