DARPA CRANE – A toolset for the design of compact fluidic distribution systems for flow control applications: Part 1 – Model development and system optimisation

This paper describes an engineering toolset developed to enable early-stage design of compact fluidic distribution systems for flow control applications. The distribution system is conceived from conventional internal flow system components such as diffusers, pipes, and turns. The design objective is to transfer the flow from an inlet pipe to a high aspect ratio outlet slot via efficiently distributing the flow, turning its direction, and reducing its velocity before entering the plenum ending with the exit slot. In doing so, the total pressure drop within the system is minimised. Analytical and semi-empirical models of components have been used whenever available. For more complex components where such models do not exist, reduced-order models based on numerical simulations were produced. The developed toolset was used to identify optimum system layouts while adhering to compactness constraints. We considered an example wing trailing-edge use case with a slot of length 1m and thickness 0.5mm, and overall system chordwise depth limit of 16cm. It was shown that for such distribution system, a total pressure drop of just above 3.5% can be achieved. Moreover, if the system compactness is increased by reducing chordwise extent by 30%, the total pressure drop only increases to 4.2%.