Unsteady-RANS simulation of conjugate heat transfer in a cavity with a vertical semitransparent wall

• The results show flow patterns from multicellular to unicellular.
• At 9:00 am, the solar control film increased the air temperature up to 10 °C.
• Average heat flux due to convection and radiation represents 45% and 55%.
• When the solar control film is not used, the heat flux due to radiation represents 70%.

A numerical study of the unsteady conjugate heat transfer for a square cavity with a semitransparent (glass) wall is presented. The cases with or without solar control film on the semitransparent wall were studied from 8:00 to 18:00 h. This wall interacts with the environment through the incident solar radiation and the outdoor air temperature, which were considered changing over the time. URANS (Unsteady Reynolds Averaged Navier–Stokes) model together with the model of Low-Reynolds number turbulence k–w were solved using the finite volume method. The results show flow patterns from multicellular to unicellular in different times for each case as result of the temperature in the semitransparent wall. Moreover, at approximately 9:00 am, the solar control film increased the air temperature inside the cavity up to 10 °C compared to the air temperature when the solar control film is not used. The cavity with solar control film has a lower period of time with a multicellular flow than the cavity without film. When the solar control film is used, the average heat flux due to convection and radiation represents 45% and 55%, respectively of the interior heat flux (qintqint). On the contrary, when the solar control film is not used, the heat flux due to radiation represents 70%.