NUMERICAL SIMULATION OF TURBULENT MIXED CONVECTION HEAT TRANSFER FOR AIDING FLOWS IN VERTICAL FLAT CHANNEL WITH SYMMETRICAL HEATING

Numerical two-dimensional simulation of turbulent heat transfer in symmetrically heated (q_w1 = q_w2 = const) vertical flat channel was performed in wide range of buoyancy parameters Bo = Gr_q / (Re^3.425 Pr^0.8) using low Reynolds number Chen-Kim and Lam-Bremhorst k−ε turbulence models. It was established when comparing with experimental data that the Chen-Kim turbulent model can simulate heat transfer in vertical short (x/d_e < 20) channels with a relative error less than 15% when the buoyancy parameter is below the critical values (Bo < Bo_cr). It was also demonstrated that the Lam-Bremhorst model can simulate heal transfer with a relative error less than 15% in the quasistabilized region (x/d_e > 30) for a wide range of buoyancy parameters.