21 research outputs found
Steady interaction of a turbulent plane jet with a rectangular heated cavity
Turbulent heat transfer between a confined jet flowing in a hot rectangular
cavity is studied numerically by finite volume method using the k-w SST one
point closure turbulence model. The location of the jet inside the cavity is
chosen so that the flow is in the non-oscillation regime. The flow structure
is described for different jet-to-bottom-wall distances. A parametrical study
was conducted to identify the influence of the jet exit location and the
Reynolds number on the heat transfer coefficient. The parameters of this
study are: the jet exit Reynolds number (Re, 1560< Re <33333), the
temperature difference between the cavity heated wall and the jet exit
(DT=60°C) and the jet location inside the cavity (Lf, 2≤ Lf≤ 10 and Lh
2.5<Lh≤10). The Nusselt number increased and attained its maximum value at
the stagnation points and then decreased. The flow structure is found in good
agreement with the available experimental data. The maximum local heat
transfer between the cavity walls and the flow occurs at the potential core
end. The ratio between the stagnation point Nusselt numbers of the cavity
bottom (NuB0) to the maximum Nusselt number on the lateral cavity wall
(NuLmax) decreased with the Reynolds number for all considered impinging
distances. For a given lateral confinement, the stagnation Nusselt number of
the asymmetrical interaction Lh≠10 is almost equal to that of the symmetrical
interaction Lh=10
Turbulent heat transfer for impinging jet flowing inside a cylindrical hot cavity
Convective heat transfer from an isothermal hot cylindrical cavity due to a turbulent round jet impingement is investigated numerically. Three-dimensional turbulent flow is considered in this work. The Reynolds stress second order turbulence model with wall standard treatment is used for the turbulence predictions the problem parameters are the jet exit Reynolds number, ranging from 2·104 to 105 and the normalized impinging distance to the cavity bottom and the jet exit Lf, ranging from 4 to 35. The computed flow patterns and isotherms for various combinations of these parameters are analyzed in order to understand the effect of the cavity confinement on the heat transfer phenomena. The flow in the cavity is divided into three parts, the area of free jet, and the area of the jet interaction with the reverse flow and the semi-quiescent flow in the region of the cavity bottom. The distribution of the local and mean Nusselt numbers along the cavity walls for above combinations of the flow parameters are detailed. Results are compared against to corresponding cases for impinging jet on a plate for the case of the bottom wall. The analysis reveals that the average Nusselt number increases considerably with the jet exit Reynolds number. Finally, it was found that the average Nusselt number at the stagnation point could be correlated by a relationship in the form Nu = f(Lf, Re
Turbulent heat transfer for impinging jet flowing inside a cylindrical hot cavity
Convective heat transfer from an isothermal hot cylindrical cavity due to a
turbulent round jet impingement is investigated numerically.
Three-dimensional turbulent flow is considered in this work. The Reynolds
stress second order turbulence model with wall standard treatment is used for
the turbulence predictions the problem parameters are the jet exit Reynolds
number, ranging from 2x104 to 105and the normalized impinging distance to the
cavity bottom and the jet exit Lf, ranging from 4 to 35. The computed flow
patterns and isotherms for various combinations of these parameters are
analyzed in order to understand the effect of the cavity confinement on the
heat transfer phenomena. The flow in the cavity is divided into three parts,
the area of free jet, and the area of the jet interaction with the reverse
flow and the semi-quiescent flow in the region of the cavity bottom. The
distribution of the local and mean Nusselt numbers along the cavity walls for
above combinations of the flow parameters are detailed. Results are compared
against to corresponding cases for impinging jet on a plate for the case of
the bottom wall. The analysis reveals that the average Nusselt number
increases considerably with the jet exit Reynolds number. Finally, it was
found that the average Nusselt number at the stagnation point could be
correlated by a relationship in the form Nu=f(Lf,Re)