Resumo (PT):
Abstract (EN):
The local energy losses established in pipe junctions, which are common features of
piping networks, are highly dependent on some geometrical features and on flow
characteristics. For the development of a generalized predictive model addressing those
energy losses, it is essential to define a database covering wide ranges of the mentioned
variables so that comparisons and validations can be made.
The present work was based on an experimental study developed on a FCT experimental
project that was on the basis of a M.Sc. thesis of one of the authors. The aim of this study
was to obtain detailed information of the flow over a 60-degree junction and of the influence
of the area ratio (branch-to-straight pipe - Ab/As) on the flow development, relating it to the
correspondent energy losses.
For this study two different geometries were considered – one with a branch-to-straight
pipe area ratio (Ab/As) equal to 1 (geom. 1) and the other with that ratio equal to 0,7 (geom.
2) – and experimentally investigated for a diverging flow configuration. The Reynolds
number, defined at the inlet pipe, was in the range of 5000 to 40000 and the working fluid
used was water. The energy losses were determined by means of characterization of the
pressure fields correspondent to the referred Reynolds number range, for different flow
division (Q1/Q3).
The physical explanation of those losses was tried by means of the study of the turbulent
flow on the bifurcation, through the characterization of the velocity field and of the
separation zones.
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
6