CALCULATION OF VERTICAL MIXING IN TWO-DIMENSIONAL TURBULENT BUOYANT SURFACE JET WITH TURBULENCE MODELS

Applicability of turbulence models to a two-dimensional buoyant surface jet is examined through comparison with experimental data. A k-ε turbulence model is found to overpredict the turbulent transport of the stresses so as to promote the vertical spreading of buoyant surface jet, because it cannot represent the anisotropy of turbulence. For taking account of the damping effects of the gravitational field and the free surface on the turbulence structure accurately, an algebraic Reynolds stress model (ASM) is examined with corrections to the pressure interaction terms at the free surface. The ASM tested produces a good agreement with measurements on the flow development and turbulence characteristics of buoyant surface jet. The predicted results also show the dependence of turbulence structure on gradient Richardson numbers.