Opposing Mixed Convection Heat Transfer in the Inclined Flat Channel in a Laminar-Turbulent Transition Region Available to Purchase

In this paper we present the results on experimental and numerical investigations of the local opposing mixed convection heat transfer in an inclined flat channel (φ = 60° from horizontal position) with symmetrical heating in the laminar-turbulent transition region. The experiments were performed in airflow (p = 0.2 and 0.4 MPa) in the range of Re from 1.5 · 10³ to 5.3 · 10⁴ and Gr_q up to 1.5 · 10¹⁰ and at the limiting condition q_w1 ≈ q_w2 ≈ const. The experimental data show similar tendencies in the heat transfer as it was revealed in vertical channel. It is already some difference in the local heat transfer for upper (stable density stratification) and bottom (unstable density stratification) walls. The data of the experimental investigations have been compared with the results of numerical modelling using Ansys Fluent 12.0 code. The modelling was performed using laminar and transition models for Re_in = 3.1 · 10³ and Gr_qin = 1.9 · 10⁹ for the same conditions as during the experiment, i.e. with the same airflow pressure (0.4 MPa), velocity, and temperature at the inlet and heat flux at the walls of the flat channel with the same geometrical characteristics.