Stability analysis and noise reduction of a cone-type poppet valve in an aero-hydraulic system

This study investigates the broadband noise generated by an aircraft steering control valve assembly during steering maneuvers. A nonlinear spool dynamics model, incorporating coupled steady-state and transient fluid forces, is established and validated through AMESim simulations and experimental test. Through this model, the critical influence between the return orifice size and the stability of cone-type poppet valve is revealed. The results demonstrate that spool stability is significantly enhanced by optimally matching the dimensions of the return and inlet orifices, which leads to an effective reduction in pressure fluctuations and vibration-induced noise. Bench tests of the optimized configuration show that the overall sound pressure level (OSPL) is reduced by more than 10 dB(A). Furthermore, on-aircraft tests confirm a peak noise reduction exceeding 20 dB(A) within the 200-800 Hz frequency band. This research offers novel insights into optimizing cone-type poppet valve stability and provides a practical engineering solution for achieving "Silent Cockpit" noise control in civil aircraft.