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Propagation of Salinity to a Lock Exchange

This is an analytical test for the accuracy of the shock speed of a density wedge.

Test Reference

  • Shin, J.O.; Dalziel, S.B and Linden, P.F. (2004). "Gravity Currents Produced by Lock Exchange", Journal of Fluid Mechanics, vol 521, pp 1-34.


  • Cuboid flume
  • 2 m length
  • 0.2 m width
  • 0.2 depth


Initial Conditions

  • Salt water 35 ppt on left
  • Fresh water 0 ppt on right

          Lock exchange initial salinity

Boundary Conditions

  • Smagorinski coefficient = 0.2
  • Background kinematic eddy viscosity = 1.0E-07 m2/sec
  • Manning's n = 0.03
  • Instantaneous barrier removal at time zero
  • No defined time varying conditions


  • Denser salt water will slump under the fresh water
  • Shock speed computed in terms of Froude Number

          Lock exchange froude

          Lock exchange froude 2

  • Shin et al. 2004 reports 'Fh' values of 0.35 to 0.5
  • This test case set up yields 'Fh' = 0.5
  • Constituent state at 16 seconds, red represents denser fluid

        Lock exchange results 16s

  • Mesh resolution can impact results:
    • With adaption

Lock exchange results adaption 16s

  • Twice refined

Lock exchange results refined 16s