This paper describes the test methodology and results for a wind tunnel experiment featuring a blended wing aircraft in ground effect with built-in circulation control. A 82.55cm wingspan blended wing model was tested in a subsonic wind tunnel at velocities ranging from 18m/s – 49m/s and corresponding Reynolds numbers ranging from 130k – 350k. Pitch angle was held constant at 0 degrees and the height above the wind tunnel floor was modified to determine lift and drag modification due to ground effect. At a normalized height (y/bw) of 0.06, ground effect increased lift production by 24% and reduced drag by 22% when compared to a normalized height of 0.5. The addition of the circulation control significantly increased the lift production of the model at a cost of increased drag. At a normalized height of 0.031, the lift production increased by 200% at a blowing coefficient of 0.01, but the drag also increased by 72%, ultimately increasing L/D by 178%. Experimental results also suggest that ground effect and circulation control have a synergistic effect when used simultaneously. The effects of Reynolds number and circulation control slot height are also investigated.
In 2013 the Irish Defence Forces went under significant reorganisation. Part of this organisation entailed integrating the Irish Army Reserve into the Defence Forces, as part of the ‘Single Force Concept’. Ostensibly, the Single Force Concept sought to provide a more reliable, fit for purpose, reserve force. However, this article argues that the concept has failed and that the Army Reserve is almost unusable. The article evaluates each service corps and provides an analysis of Reserve capabilities. This shows that the training of the force is suboptimal for augmenting the regular army in an emergency, and that a gap exists between what government policy wants the Reserve to do, and what it is actually capable of doing. This has resulted in an unusable reserve force with questionable utility. This article also highlights the difficulty of establishing the qualitative strength of the Army Reserve in the absence of appropriate means of defining what is meant by an ‘effective’ reservist, and explores the detrimental consequences of paltry financial investment in sustaining, developing, or enabling the Reserve as an effective force. It argues that the Single Force Concept has failed because it did not remedy the fundamental pre-existing flaws that plagued the various iterations of the Irish reserve land component prior to 2013, nor did it attempt to bring the Army Reserve into line with international best practice regarding reserve forces. The article concludes by arguing that the current Irish reserve model is unsustainable, and that fundamental changes are required in order to make the force usable to the State, and to prevent it from collapsing altogether.
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