Semi-empirical modeling of narrow-cone-angle hollow-cone hydrogen jet penetration

초록

Zero-dimensional modeling of hollow-cone hydrogen jet penetration is critical for precise injection control in hydrogen direct-injection engines. Although several penetration models have been proposed, most are limited to the deceleration phase and wide cone angles (>90 degrees), and studies tailored to hydrogen jets remain scarce compared to methane jets. In this study, a comprehensive model is developed to predict the entire temporal evolution of hollow-cone hydrogen jets injected from narrow-cone-angle pintle-type injectors. Schlieren imaging were conducted to characterize the transient jet behavior and revealed that the transition point between the acceleration and deceleration phases can be expressed as a function of the pressure ratio. The acceleration phase is modeled by adapting existing diesel spray penetration models for acceleration or breakup, while the deceleration phase is empirically adjusted from a conventional turbulent gas jet model. The proposed model accurately predicts jet penetration across the entire injection process, addressing limitations of previous approaches.

키워드