DARPA CRANE – A toolset for the design of compact fluidic distribution systems for flow control applications: Part 2 – Model validation and implementation

This paper describes the second part of the development process of an engineering toolset to enable early-stage design of compact fluid distribution systems for flow control applications. The distribution system is conceived from conventional internal flow system components such as diffusers, pipes, and turns with a design objective to duct high-pressure air from concentrated sources to highly spatially distributed geometries in an effective, efficient, and compact manner. In this part, an experimental rig of a typical flow distribution system is realised and pressure measurements across various locations of the system are collected and compared to results from the developed numerical tool. It was found that the average absolute difference of the pressure values is within 3.5%, validating the developed tool and providing confidence in its predictive performance. Two main insights are found: First, skin friction losses in pipes represent a primary contributor to the overall pressure drop; and second, flow turning can also lead to large losses, but this can be mitigated by slowing the flow as much as possible before turning. Finally, a simple load balancing tool is presented that tailors the area of each path within the system to ensure equal mass flow rates exist along the different paths. This improves the uniformity of the flow exiting the plenum, and is found to marginally reduce total pressure drop