Consider a turbulent flow of viscosity μt, diffusivity Γt and Prandtl/Schmidt number σt. Let Φ be a flow property which can be decomposed into Φ=Φ+Φ’. What is the turbulent scalar flux given by?

• A. –ρu’Φ’=Γt\(\frac{\partial\Phi}{\partial x}\)
• B. –ρu’Φ’=Γt\(\frac{\partial\Phi}{\partial x}\)
• C. –ρu’Φ’=μt\(\frac{\partial\Phi}{\partial x}\)
• D. –ρu’Φ’=μt\(\frac{\partial\Phi}{\partial x}\)