Question

The terms accounting for turbulence effects contain ____________

(a) Reynolds stresses

(b) Turbulent kinetic energy

(c) Dissipation of turbulent kinetic energy

(d) Length scale terms

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This is a very interesting question from Turbulence Modelling topic in division Turbulence Modelling of Computational Fluid Dynamics

Answer 1

Correct option is (a) Reynolds stresses

Explanation: The terms accounting for turbulence stresses are \(div(\rho \vec{V} \overline{u_{i}^{‘} u_{j}^{‘}})\) and \(\rho \overline{u_{i}^{‘} u_{j}^{‘}}.div(ρ\vec{V} \overline{u_{i}^{‘} u_{j}^{‘}})\) represents the turbulent transport of kinetic energy by means of Reynolds stresses. \(\rho \overline{u_{i}^{‘} u_{j}^{‘}}\) represents the net decrease of kinetic energy due to deformation work by Reynolds stresses. Both of these terms contain the Reynolds stress term \(\rho \overline{u_{i}^{‘} u_{j}^{‘}}\).