An experimental and numerical study of a 90° bifurcation

Mathioulakis, DS; Pappou, Th; Tsangaris, S

dc.contributor.author	Mathioulakis, DS	en
dc.contributor.author	Pappou, Th	en
dc.contributor.author	Tsangaris, S	en
dc.date.accessioned	2014-03-01T01:12:37Z
dc.date.available	2014-03-01T01:12:37Z
dc.date.issued	1997	en
dc.identifier.issn	01695983	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/12169
dc.subject	Coordinate System	en
dc.subject	Experimental Data	en
dc.subject	Flow Field	en
dc.subject	Flow Rate	en
dc.subject	Flow Visualization	en
dc.subject	Horizontal Branch	en
dc.subject	Numerical Method	en
dc.subject	Reynolds Number	en
dc.subject	Secondary Flow	en
dc.subject	Three Dimensional	en
dc.subject	Vortex Shedding	en
dc.subject	Characteristic Frequency	en
dc.subject.other	Ducts	en
dc.subject.other	Laser Doppler velocimeters	en
dc.subject.other	Numerical analysis	en
dc.subject.other	Numerical methods	en
dc.subject.other	Reynolds number	en
dc.subject.other	Velocity measurement	en
dc.subject.other	Bifurcation	en
dc.subject.other	Branch flow rate	en
dc.subject.other	Flow field	en
dc.subject.other	Secondary flow	en
dc.subject.other	Time mean streamwise velocity	en
dc.subject.other	Flow of fluids	en
dc.subject.other	bifurcations	en
dc.subject.other	flow fields	en
dc.subject.other	flow visualization	en
dc.subject.other	Reynolds number	en
dc.title	An experimental and numerical study of a 90° bifurcation	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/S0169-5983(96)00023-8	en
heal.identifier.secondary	http://dx.doi.org/10.1016/S0169-5983(96)00023-8	en
heal.publicationDate	1997	en
heal.abstract	The flow field of a 90° square duct bifurcation was examined both experimentally and numerically for a Reynolds number of 1200 and equal branch flow rates. Velocity measurements were carried out with a one-component LDV, recording, besides the time mean streamwise velocity component, its time variation due to vortex shedding which took place in the extension of the main duct, as well as secondary flow velocities in the 90° branch. Flow visualization provided additional information about the three-dimensional character of the flow field by recording the paths of neutrally buoyant solid particles. The experimental data were compared with the results of a numerical method, constituting an extension of the well-known SOLA method to a 3-D generalized coordinate system, presented here for the first time. These comparisons were very successful in the vertical branch but less satisfactory in the horizontal branch where unsteadiness was very strong. The characteristic frequency of the velocity fluctuations in the detached shear layer of the horizontal branch was very well predicted but the velocity amplitudes were underestimated. The predicted secondary flow in the vertical branch was compared well with the experimental data presenting maximum values close to the inlet mean velocity.	en
heal.journalName	Fluid Dynamics Research	en
dc.identifier.doi	10.1016/S0169-5983(96)00023-8	en
dc.identifier.volume	19	en
dc.identifier.issue	1	en
dc.identifier.spage	1	en
dc.identifier.epage	26	en