Numerical Analysis of Combustion Stability and Efficiency Improvement in Ammonia Engine Utilizing Passive Turbulent Jet Ignition (PTJI) Chosun University

Format:

Book

Conference/Event

Author/Creator:

Ju, Kangmin, author.

Contributor:

Kang, Hyun-Ung

Kim, Jeong Hyeon

Conference Name:

SETC2025: 29th Small Powertrains and Energy Systems Technology Conference (2025-11-10 : Florence, Italy)

Language:

English

Physical Description:

1 online resource cm

Place of Publication:

Warrendale, PA SAE International 2025

Summary:

Ammonia, a carbon-neutral fuel, is a promising candidate for next-generation engine applications. However, its low flame speed (~7cm/s) and prolonged ignition delay (~10ms at stoichiometric conditions) impose significant challenges in achieving stable and efficient combustion across varying operating conditions. At high-speeds, incomplete combustion due to limited residence time reduces efficiency, while at low-speeds, ignition instability and low combustion temperatures hinder reliable operation. To address these challenges, the Passive Turbulent Jet Ignition (PTJI) system has been proposed to enhance turbulence-driven mixing and improve ignition characteristics. This study focuses on optimizing a PTJI system for ammonia-fueled engines using a three-phase methodology. First, the 800cc 2-cylinder gasoline engine was modified for ammonia using numerical analysis, and a baseline analysis of the combustion characteristics was conducted. Next, a turbulent intensity study within the PTJI system was performed to determine an optimal configuration for stable combustion. Results show that PTJI increased turbulent intensity by up to 120% compared to conventional spark ignition, enhancing flame propagation and reducing ignition delay. Finally, PTJI effectiveness was evaluated under both high-speed and low-speed conditions. At 2000rpm, PTJI increased combustion temperature by ~150K, improving ignition stability and reducing cycle-to-cycle variations, thereby improving the convergence of the analysis. At 3000rpm, PTJI accelerated flame propagation speed by ~50%, facilitating complete fuel-air mixture combustion and enhancing thermal efficiency. In conclusion, this research demonstrates that PTJI is a viable solution for overcoming the inherent limitations of ammonia combustion. By increasing turbulence intensity and improving flame propagation, PTJI enables more stable and efficient ammonia engine operation, offering a promising approach for future carbon-neutral powertrains

Notes:

Vendor supplied data

Publisher Number:

2025-32-0049

Access Restriction:

Restricted for use by site license