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Formation of Jets by Impulsive Acceleration of a Curved Free Surface


Gruber, William Paul (1968) Formation of Jets by Impulsive Acceleration of a Curved Free Surface. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/SWXB-0X23.


The sudden axial acceleration of a column of liquid bounded at one end by a concave free surface has been found, experimentally, to produce a jet which issues from the free surface with a speed several times that imparted to the column.

Theoretical approximations to such flows, valid for small time, are formulated subject to the assumption that the fluid is inviscid and incompressible. In a special two-dimensional case, it is found that, for vanishingly small time, the velocity at the point on the free surface from which the jet emanates is π/2 times the velocity imparted to the column. The solutions to several problems in two and three dimensions assuming that the initial curvature of the free surface is small, lead to values for this ratio dependent upon the curvature—the initial velocity in the case of axial symmetry exceeding that of the analogous two-dimensional problem by approximately 25%.

Experiments conducted upon the phenomenon give values systematically in excess of those predicted by the theory, although theory and experiment are in qualitative agreement with respect to the displacement of the free surface. It is suggested that the discrepancy is attributable to effects of finite curvature having been imperfectly accounted for in the axially-symmetric analysis.

Photographic materials on pp. 115, 120, and 121 are essential and will not reproduce clearly on Xerox copies. Photographic copies should be ordered.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:(Mechanical Engineering)
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Mechanical Engineering
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Ellis, Albert T.
Thesis Committee:
  • Unknown, Unknown
Defense Date:21 May 1968
Funding AgencyGrant Number
Alfred P. Sloan FoundationUNSPECIFIED
Office of Naval ResearchNonr-220(44)
Record Number:CaltechTHESIS:12072015-132454281
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:9310
Deposited On:07 Dec 2015 21:57
Last Modified:02 Apr 2024 17:56

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