Indoor thermal environment analysis (summer)
OpenFOAM is used to simulate the heat flow distribution in a simple building and its internal space when exposed to solar radiation. A transient calculation is performed from 6:00 to 18:00, a steady-state calculation is performed at 16:00, which is the peak time in summer, and a steady-state calculation is performed when the air conditioner is operating during the peak time in summer.
Transient analysis - Analysis model and various conditions
・Analysis assuming July 22nd, 6am to 6pm
・Outside temperature: 27℃, Underfloor temperature: 27℃
Latitude: 35.7°C, Longitude: 139.7°C
- The window is assumed to be completely transparent to solar radiation, and the reflector is assumed to be completely specularly reflective of solar radiation.
-Solar radiation heat is generated on the ceiling, floor, and walls using OpenFOAM's solar radiation function.
It also takes radiation (ViewFactor) into account.
*It may seem unnatural to have a reflector behind the window, but we have installed it to confirm that transmission and reflection can be calculated.
Video of time-varying surface temperature distribution
Steady-state analysis
- Analysis model and various conditions
・July 22nd, 4pm = Analysis assuming summer peak time
・Outside temperature: 38℃, Underfloor temperature: 38℃
Latitude: 35.7°C, Longitude: 139.7°C
- The window is assumed to be completely transparent to solar radiation, while the reflector is assumed to be completely specularly reflecting solar radiation.
-Solar radiation heat is generated on the ceiling, floor, and walls using OpenFOAM's solar radiation function.
It also takes radiation (ViewFactor) into account.
Internal temperature cross section
Steady-state analysis (air conditioner installation)
- Analysis model and various conditions
・July 22nd, 4pm = Analysis assuming summer peak time
・Outside temperature: 38℃, Underfloor temperature: 38℃
Latitude: 35.7°C, Longitude: 139.7°C
- The window is assumed to be completely transparent to solar radiation, and the reflector is assumed to be completely specularly reflective of solar radiation.
-Solar radiation heat is generated on the ceiling, floor, and walls using OpenFOAM's solar radiation function.
It also takes radiation (ViewFactor) into account.
Air conditioner: 157 x 272 x 105 cm, air volume: 1,513 cmH, outlet: 43.7 x 231 cm, outlet temperature: 17°C
Detail of technology
-The solver used is chtMultiRegionFoam.
-Radiation is a ViewFactor model.