Three-Dimensional Pulsating Flow Simulation in a Multi-Point Gas Admission Valve for Large-Bore CNG Engines

Abstract

This study examines the dynamic fluid behavior of a PWM-controlled Solenoid-Operated Gas Admission Valve (SOGAV) for large-bore CNG engines using 3D Computational Fluid Dynamics (CFD) simulations with dynamic mesh techniques. The research focuses on the influence of orifice geometry variations in the multi-hole restrictor and pressure differentials between the inlet and outlet on flow stability, turbulence, and valve performance. Results demonstrate that multi-hole restrictors with different-sized orifices improve flow uniformity and reduce turbulence, thereby mitigating flow resistance. Transient simulations further reveal standing wave formation and pressure wave interference, emphasizing that steady-state models cannot capture critical transient phenomena, such as accelerated and decelerated jet-like flows and flow separation. These findings provide key insights into SOGAV optimization, contributing to enhanced fuel efficiency and engine responsiveness, meeting the performance requirements of modern gas engines.