Experimental and numerical investigation of flow characteristics in an open rectangular cavity

Turbulent flow over open cavity has been investigated experimentally in water channel using Acoustic Doppler Velocimetry (ADV) and numerically using FLUENT. The mean velocity and turbulent kinetic energy distribution of the flow over cavity having an aspect ratio, l/d = 2 (where l and d is the length and depth of the cavity) obtained from FLUENT are validated by experimental results. Effects of different Reynolds numbers and aspect ratios of the cavity (i.e. l/d = 1, 2 and 4) on the flow are reported. The results show that there exists a critical Reynolds number at which the trend of variation of physical variables breaks in response to the change in Reynolds numbers. Recirculating zone inside the cavity for l/d = 1, interacts with downstream cavity flow whereas, for l/d = 2 and 4, the mass exchange between the cavity and upstream flow is noticed. As the aspect ratio is increased, the upstream flow becomes more attached and the instability near the trailing edge increases.