94 mechanism using balls, arc latches or snap wires engages. They can then be disconnected by pulling a sleeve on the coupler, releasing the latch quickly. Alternately, threaded fluid connectors use independently-swivelling threaded components, preventing torsional loads on connecting hoses during attachment or detachment. The large bearing surfaces in these devices ensure reliable connections, even amid intense vibrations or high g-forces. Bayonet-type locks are also used in fluid connectors, including some with hook-like receptacles, which require additional, deliberate movements for unmating, meaning greater security than typical bayonet latches. In recent years, customer requests to resolve certain key issues have spurred innovative solutions in response. For instance, pressure drop – where liquid passing between an inlet and outlet suffers loss of pressure, possibly due to friction or other forces along the length of the channel – can render liquid cooling systems considerably less effective, and sap the efficiency of oil or fuel pumps. Minimising pressure drop across connectors has therefore been a critical focus, motivating extensive CFD simulations in ANSYS to optimise internal flow paths, reducing turbulence, resistance and energy costs, and improving overall system efficiencies in high-performance fluid connectors. The accuracy of CAD and CFD simulations in fluid connectors depends (like simulations across other devices) on copious data to enable designs to behave in digital environments just as they do in the real world. As such data is limited in open-source forums, fluid connector suppliers who engage in the most projects and prototyping each year will have the advantage in mitigating fluidspecific problems akin to pressure drop. One design integrates a relief mechanism, by which over-pressurisation events driven by thermal expansion will trigger a controlled release of limited fluid, safely reducing pressure and preventing the coupling from being blown. An even newer fuel-connection device that is useful in UAVs incorporates a pressure equalisation system, integrating two back-to-back check valves, each with distinct cracking pressures and flow paths. These effectively balance internal and external pressures: during climbing, when external pressure drops, a valve safely releases air or fuel to prevent an explosion. In dives, a valve allows air to enter the tank, protecting it from collapsing. The system also prevents pressure build-ups stemming from thermal expansion, helping to reduce the risk of over-pressurisation events. Meanwhile, material innovations in this space include the use of various lightweight, high-strength alloys, as well as some aimed at functioning in cryogenic temperatures as low as -200 C to high temperatures exceeding 170 C – ideal for space exploration, advanced UAV cooling systems and nextgeneration propulsion technologies. At least one US supplier is also sourcing domestically-traceable materials to comply with Defense Federal Acquisition Regulation (DFAR) requirements, and thus suit military and defence users. Engineering Prudent design of any new connector product often depends on close collaboration between multiple disciplines across manufacturing companies. With functionality paramount, the first step in defining a new system is to identify requirements, with product managers often gleaning these from the market and informing the designers accordingly. Those designers must then work closely with mechanical engineers, as well as experts on electrical engineering and signal integrity, to begin concept work and simulations on a basis that ensures both power and data wind up flowing seamlessly through the resulting connector without interference, insertion losses or other issues. Production experts ought to be included in the collaborative development process. Designing a connector that will perform is one thing, but the design must account for how the wires will be stripped, soldered or crimped to integrate the connector to the cable. Subsequently, the design should account for how additional components such as shielding or bonding resins will be included in the integration process without causing problems like resin seeping under the shielding and amidst the wires. Throughout the design simulations and real-world tests that follow, it is increasingly common practice for connector manufacturers to analyse signal integrity to ease the end-user’s workload in creating a functional vehicle data network. As well as simulating for signal integrity, equipment such as vector-network analysers can be critical for affirming the amplitude and phase properties of signal transmissions through a new connector’s prototypes. Signal integrity tests and in-depth analysis will become increasingly crucial aspects of cable assembly engineering as new high-speed data protocols, compression standards and levels of EMI inside uncrewed vehicles push connector February/March 2025 | Uncrewed Systems Technology High-performance fluid connectors depend on extensive CFD modelling and then precise CNC machining to optimise for internal flow (Image courtesy of Battlefield International)
RkJQdWJsaXNoZXIy MjI2Mzk4