Three-dimension efflux velocity characteristics of marine propeller jets

Gerard Hamill, Charmaine Kee, Donal Ryan

Research output: Contribution to journalArticlepeer-review

26 Citations (Scopus)


Determining the efflux velocity in a ship's propeller jet is the key to calculating the velocity at any other location within the diffusing jet. Current semi-empirical equations used to calculate the magnitude of the efflux velocity have been based on studies that employed a limited range of propeller characteristics. This paper reports on the findings of an experimental investigation into the magnitude of the efflux velocities of the jets produced by four different propellers, where the characteristic of the blade geometry has been chosen to extend the range of applicability of the outcomes. Measurements of velocity have been made using a three-dimensional laser Doppler anemometry system, with the test propellers operating at a range of rotational speeds that bound typical operational values. Comparisons are made with current predictive theories and, to aid engineers in the design of marine infrastructure, methods are presented by which the three-dimensional efflux velocity components, as well as the resultant efflux value, can be more accurately determined.
Original languageEnglish
Pages (from-to)62-75
Number of pages14
JournalProceedings of the Institution of Civil Engineers - Maritime Engineering
Issue number2
Publication statusPublished - 18 Sept 2015


  • Propeller
  • jet
  • scour
  • PIV


Dive into the research topics of 'Three-dimension efflux velocity characteristics of marine propeller jets'. Together they form a unique fingerprint.

Cite this