Solar Shading Double Glazing façade

Description

This project simulates the radiation of solar rays into the interior of a room using ANSYS Fluent, taking into account a wooden partition acting as solar shading together with a double-glazed façade. Argon gas fills the gap between the two panes of the double glazing; because argon has a low thermal conductivity, it acts as an insulating layer that reduces heat transfer from the outdoor environment into the room. Radiative heat transfer from the sun is the central physics of the study, so a radiation model is used — here the P1 model — together with the solar ray tracing feature to define the incoming solar radiation.

The room is located at a latitude of 24 degrees and a longitude of 26 degrees, with the case set at 1 p.m. on the 30th of June. The directions of the sun's rays are computed from the room's geographic longitude and orientation. The glass walls adjacent to the room are defined as semi-transparent, meaning the sun's rays can be absorbed, transmitted, or reflected at these surfaces. The solar shading, by contrast, is treated as an opaque body that only absorbs and reflects the rays and does not allow them to pass through.

Geometry & Mesh

The model was built in 3D using Design Modeler and represents a room connected to an outdoor space through a wooden partition (solar shading) and a double-glazed façade. The room is 6 m deep, 5 m wide, and 3 m high, and the gap between the panes of the double glazing is 2 mm. Meshing was performed in ANSYS Meshing using a structured grid of 239,760 elements.

Methodology

Several assumptions underpin the simulation: a pressure-based solver is used, the simulation is steady, and gravitational effects on the fluid are neglected.

Viscous model — standard k-epsilon with standard wall functions

Radiation model — P1, with the solar ray tracing solar-load model

Energy — enabled

Boundary conditions — Glass 1: stationary wall, convection thermal condition (heat transfer coefficient 20 W/m²·K, free-stream temperature 310 K), semi-transparent; Glass 2 and Glass 3: stationary walls, coupled thermal condition, semi-transparent; Wood (solar shading): stationary wall, coupled thermal condition, opaque; Room and Argon walls: stationary walls, convection thermal condition (20 W/m²·K, 310 K), opaque

Methods — SIMPLE pressure-velocity coupling; second-order for pressure; second-order upwind for density, momentum, and energy; first-order upwind for turbulent kinetic energy and dissipation rate

Initialization — standard method, with 0 Pa gauge pressure, zero velocity, and a temperature of 310 K

Conclusion

On completion of the solution, two- and three-dimensional results for temperature, pressure, and velocity were obtained, along with velocity information on a plane through the middle of the model. The results clearly show the circulation of air within the room's interior spaces and the rise in temperature throughout the domain caused by the solar radiation.

Overall, the study demonstrates how the P1 radiation model combined with solar ray tracing captures the entry of solar energy through a double-glazed, semi-transparent façade and the moderating effect of the wooden solar shading — illustrating how radiative solar loading drives the thermal behavior of a room and how shading and insulated glazing can be used to control it.