Development and Simulation of a Test System for Analyzing High Flow Rate Digital Flow Control Units

In the realm of hydraulic systems, digitally controlled valves, configured in parallel, are essential for precision and efficiency in various applications, from industrial machinery to mobile technology. Though not widely adopted, have been studied in various domains and configurations. However, a significant knowledge gap exists in testing these systems under high flow-rate conditions. This study introduces a specialized test system aimed at examining digital hydraulic units in such scenarios (up to 750 LPM and 280bar). The system design integrates a power source for high inlet pressure and flow, accompanied with resistive loading to mimic different operational conditions. This approach provides a comprehensive and adaptable testing framework, crucial for exploring the dynamics of digital hydraulic systems under extreme flow rates. Initial simulations conducted using this system yielded insightful results. A noticeable finding was the effect of the resistive relief valve on the flow fluctuations and the outlet pressure values, particularly prominent with high flow rate demands. Moreover, the deterministic requirement of the accumulator during testing, along with accurate sizing, contributes to the flow dynamics of the system during transient states. These observations are crucial for understanding the behavior of digital hydraulic systems in binary series under various loads. They reveal different flow patterns (crests and troughs) during transient states, demonstrating the entangled valve operations, particularly when externally piloted, stroke-limited valves are added to the digital hydraulics library. The successful development and implementation of this test rig represent a significant advancement in hydraulic system testing.