Modelling of spatially and temporally-varying cavity pressures in air-permeable, double-layer roof systems

摘要: This paper discusses the development of an analytical model to simulate time-varying pressure distributions (Cpi) in cavity air-permeable layer, double-layer systems, given data on external surface (Cpe). The was derived considering drops associated with flow through gaps between panels, which is like orifice flow, and parallel plates. Thus, uses two primary equations: unsteady discharge equation for accounts several geometric parameters including gap (G) height (H) panel above airtight layer length (L) as well loss coefficients flows. proposed able capture fluctuations Cpi a good agreement found numerical experimental results mean, RMS peak coefficients, great extent, when spanwise-averaged are used input. For large gap-to-height ratios (i.e., G/H = 12.5), accuracy decreases.