Laser Doppler anemometry of a wave affected turbulent jet

Experimental results from the imposition of gravity waves upon a turbulent jet are presented. Velocity and turbulence correlations between gravity wave parameters and turbulent jet characteristics are determined.; A submerged turbulent jet is modeled in a laboratory and a Laser Doppler Anemometry system is used to measure velocity and turbulence readings. Measurements of machine-generated gravity waves are also performed with the LDA system. Finally, LDA measurements of the jet under the effects of the waves are performed for twelve separate wave cases.; The turbulent jet results agree with the findings of previous studies. LDA measurements of the waves show that the location of highest turbulence occurs below the wave trough. The characteristics of the turbulent jet are directly affected by the imposed wave power. For wave powers of less than 2 lb/s, a power increase affects the jet in the same manner as raising the jet Reynolds number. For wave powers of greater than 2 lb/s, a power increase raises the jet dilution. The jet velocity profiles, which are not skewed by the waves, remain Gaussian under the wave effects. The turbulence profiles are skewed and shifted towards the water surface in accordance with the wave power.; It is shown that gravity waves significantly increase the dilution achieved by turbulent jets. It is suggested that persistent waves, which are typical of an ocean outfall location, be accounted for in calculating the expected dilution. In doing so, design dilutions may be achieved in shallower water and closer to shore than is indicated by conventional design procedures, thus creating significant savings in material and construction costs.