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Title: A study of the free spiral vortex
Author: Quick, M. C.
ISNI:       0000 0004 2741 393X
Awarding Body: University of Bristol
Current Institution: University of Bristol
Date of Award: 1961
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The occurrence or rree spiral vortices at pump intakes and reservoir bellmouth spillways can cause considerable loss of efficiency by reducing the quantity of flow and by entraining air. To understand the mechanism and formation of these vortices an investigation has been made under steady and controlled conditions, measurements of surface profile, velocity distribution and discharge being made and compared with the results calculated from non-viscous theory. Vortices in two sizes ot geometrically similar apparatuB have also been studied to determine the velocity scale relationship for similarity. The formation of steady vortices has been investigated for outlets drawing water both upwards and downwards trom a vessel and the conditions for air entrainment to occur has been shown to be different tor these two directions of outlet. The transient formation of vortices at these outlets is also discussed and it is seen that direction of outlet is, then, not important but the outlet velocity compared with Bubmergence is a principal tactor. From this work three independent conditions tor the prevention of such vortices are found. The behaviour ot a vortex core atter it has entered an outlet was also studied. With a downwards outlet the air-core could persist, but conditions were ~ound when a sudden transition to pipe-fUll flow could occur and this transition has been called the annular hydraulic jump. An analysis o~ this transition was made by making certain simplifying assumptions which were shown to be justi~ied by the agreement round between experiment and analysis.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available