Thermal Plume

The development of computational fluid dynamics (CFD) made it possible to simulate the detailed flow field and temperature field within the room. The various studies numerically investigated the flow and temperature field both inside and outside the buildings. When investigating the indoor environment, human is an important factor since it perceives the indoor environment and behaves as a source of heat and contaminant as well. Some studies investigated deeper into humans by developing detailed computer-simulated persons (CSP).

An accurate temperature gradient calculation is essential for displacement ventilation (DV) system design, since it directly relates to the calculation of supply air flow rate. Several simplified nodal models were developed and implemented in the various building simulation programmes in order to estimate the temperature stratification in rooms with displacement ventilation. However, the most commonly used models do not count the types and locations of the typical heat loads in rooms with displacement ventilation.

The impact of clothing, breathing and body posture on the thermal plume above a thermal manikin was investigated. Measurements of air velocity and temperature above the manikin were performed at four different heights above a sitting and a lying manikin. The results obtained from tests above the sitting manikin show an inverse proportion between the thermal insulation of clothing and the air velocity in the thermal plume. Air velocity in the thermal plume with the breathing function switched on equalled 90-98% of the values obtained for non-breathing experiments.

Recently, Island kitchen is installed in many houses in Japan. In the island kitchen, the cooking range is placed on the island unit, and the center hood is located above the cooking flow in the room. In such a kitchen environment, there is a possibility that cross winds or other disturbing flow may reach the cooking zone. For this reason, pollutant fumes from the cooking range may be diffused to residential zone. CFD analysis is an effective measure for comprehending such a diffusion of the thermal plume.