Turbulent natural convection in an air-filled isosceles triangular enclosure

Effects of Roof Pitch on Air Flow and Heating Load of Sealed and Vented Attics for Gable-Roof Residential Buildings

“…Although the geometry and boundary conditions are symmetric about x = 0, the predicted air flows in the sealed attics are asymmetric, independent of the roof pitch variation. The asymmetric flow pattern found here is consistent with the previous numerical studies (e.g., [17,18,22]) and the experimental results of Holtzman et al [10]. In this flow visualization experiment, smoke was slowly injected into an air-filled triangular enclosure, which was constructed of aluminum plates with milled passageways for circulating fluid to maintain isothermal surfaces and to impose a temperature difference between the base and upper walls.…”

“…Although the air flow in real residential attics is almost always turbulent, a considerable number of experimental and numerical studies have been devoted to the analysis of flow and heat transfer under laminar conditions (e.g., [7][8][9][10][11][12][13][14][15][16]), and only a few studies investigated turbulent flow and heat transfer in sealed attics. For example, Ridouane et al [17] employed a low-Reynolds-number k-ε model to simulate the turbulent natural convection in an air-filled isosceles triangular enclosure representing attic spaces under winter conditions, and Talabi et al [18] numerically investigated the turbulent natural convections in sealed attics under both summer and winter conditions using the Reynolds stress turbulence model and considering both isothermal and isoflux boundary conditions. Air flow and heat transfer in vented attic spaces have been scarcely investigated in the past.…”

Numerical simulation of buoyancy-driven turbulent ventilation in attic space under winter conditions

“…The second benchmark problem adopted to validate the present model is turbulent natural convection of air confined in an isosceles triangle-shaped attic, which was originally solved by Ridouane et al [16]. The modeled domain has a width of 5.46 m and a height of 2.73 m. A uniform temperature of 273 K is applied to the roofs, while the ceiling is kept at 293 K. The streamlines and isotherms predicted by the present model are shown in Figure 4.…”

“…While a considerable number of experimental and numerical studies (e.g., [6][7][8][9][10][11][12][13][14][15]) have been devoted to the analysis of flow and heat transfer under laminar conditions, only a few studies (e.g., [16,17]) investigated turbulent flow and heat transfer. For realistic sizes of residential attics, the air flow is almost always in the turbulent regime.…”

Impacts of Ventilation Ratio and Vent Balance on Cooling Load and Air Flow of Naturally Ventilated Attics

“…In the first category, sealed attic configuration is considered, and the problem is usually represented by natural convection in triangular enclosures. As reviewed by Kamiyo et al [5] and by Saha and Khan [6], a considerable number of experimental and numerical studies in this category (e.g., [7][8][9][10][11][12][13][14][15][16]) have been devoted to the analysis of flow and heat transfer under laminar conditions, while only a few studies (e.g., [17,18]) investigated turbulent flow and heat transfer, although the air flow in real residential attics is almost always turbulent.…”