Saddington, A. J.Knowles, KevinThangamani, Varun2019-11-292019-11-292015-12-11Saddington A, Knowles K, Thangamani V. (2016) Scale effects on the performance of sawtooth spoilers in transonic rectangular cavity flow. Experiments in Fluids, Volume 57, Issue 2, January 2016, Article Number 20723-4864https://doi.org/10.1007/s00348-015-2088-2http://dspace.lib.cranfield.ac.uk/handle/1826/14785An experimental study was conducted on the effectiveness of sawtooth spoilers at suppressing acoustic tones within a rectangular cavity with a length-to-depth ratio of five and a width-to-depth ratio of two, operating at a freestream Mach number of 0.71. Whereas previous research has focussed on the ratio of spoiler height to boundary-layer thickness (h/δ), this study also considers the effect of the ratio of cavity length to boundary-layer thickness (L/δ). Using a combination of unsteady pressure measurements and particle image velocimetry, it was established that consideration of the magnitude of both parameters is important when designing passive control methods for transonic cavities. A correlation was developed which suggests that in order to suppress fully the cavity tones, a critical spoiler height, h cr, is defined such that h cr/δ = 0.065 ≤ L/δ ≤ 0.082.enAttribution 4.0 InternationalParticle Image VelocimetryShear LayerParticle Image Velocimetry MeasurementBroadband NoiseParticle Image Velocimetry DataArticle4090465