Flow and heat transfer in round vertical buoyant jets

Numerical Analysis of Recirculation Bubble Sizes of Turbulent Co-Flowing Jet

“…The authors took the velocities ratio R u equal to 0.01, the initial turbulent kinetic energy and its dissipation rate, respectively, equal to 0.05 and 0.02. For both turbulence models and different Froude numbers, in Figure 13 we depict the longitudinal distributions of the excess velocity, the temperature, and the turbulence kinetic energy which are reported by Martynenko and Korovkin (1994). For the excess velocity, we obtained close results from the two turbulence models.…”

“…In the same Figure 13 we observe also that, in the plume region, the results are independent of the Froude number for both turbulence models (low ). It is found that the numerical simulations of the behavior at the jet axis can be estimated by the correlations proposed by Martynenko and Korovkin. (1994): (19) Engineering Applications of Computational Fluid Mechanics Vol.…”

“…To validate the numerical computations obtained from the standard k- and RSM models, we used the results obtained by Martynenko and Korovkin (1994). The authors took the velocities ratio R u equal to 0.01, the initial turbulent kinetic energy and its dissipation rate, respectively, equal to 0.05 and 0.02.…”

“…[Chen and Rodi, 1980] Co The values of coefficients of A u , A  and A k are given in Table 5. This table includes the predicted coefficients of our study obtained from the k- and RSM models, the numerical predictions of Martynenko and Korovkin (1994), Hossain and Rodi (1982) and Habli et al (2008) and the experimental data of Papanicolaou and List (1987), Ogino et al (1980) and Chen and Rodi (1980). From the results in the Table 5 we noted that some of them coincide with the values obtained from the free-jet case.…”

Accounting for the effects of buoyancy on the turbulent scalar fluxes

“…As these models require considerable computational effort (in three-dimensional flows, the solution of 11 differential transport equations consisting of 6 equations for the components of the Reynolds-stress tensor, 3 equations for the components of the turbulent scalar fluxes, an equation for the dissipation rate of the turbulence kinetic energy, and one for the scalar variance), considerable efforts have been directed towards the formulation of models consisting of algebraic expressions from which the Reynolds stresses and the turbulent scalar fluxes can be obtained (e.g. [2,3]). A desirable feature in an algebraic 1 3 model is that it should be explicit in the turbulent scalar fluxes.…”