Investigation of Trapped Vorticity Concentrations Effected by Hybrid Actuation in an Offset Diffuser

Fluidic Control of an Aggressive Offset Diffuser for a Supersonic Inlet

“…These modes are associated with the formation of two large-scale vortical structures that are formed by the merging of arrays of small-scale actuation vortices. Recently, Burrows et al (2016) demonstrated experimentally that active flow control can alter the strength, scale, and structural topology of trapped vorticity (that was deliberately engendered in the diffuser flow) and consequently its interactions with the cross-flow, leading to significant reduction in the overall flow distortion at the AIP (up to about 80% at M = 0.7 and actuation mass flow rate ratio C q < 0.7%). In a subsequent joint experimental and numerical study, Vukasinovic et al 2017showed that further optimization of the same flow control approach can yield a reduction of about 68% in distortion at C q as low as 0.25%.…”

“…A spanwise array of 17 equally-spaced (6.3 mm apart) fluidic oscillating jets (similar to the array of Burrows et al, 2016), is located upstream of separation (as determined by surface oil visualization) in the second turn ( Figure 5a). Each jet orifice measures 1.5 × 2 mm, with an operating frequency between f = 7 -9 kHz over a range of flow rates.…”