Flexible Clean Propulsion Technologies

VVA-enabled Ultra-Efficient RCCI Combustion Development in a Medium Speed Marine Engine Platform

Author

Jeyoung Kim , Maciej Mikulski , Hunicz Jacek

Category

Publication channel

Keywords

Variable Valve Actuation (VVA), Efficient Powertrain Solutions, Combustion Research, Energy Transition., PhD Research, Engine Development, Large Engine Symposium, Rostock, Clean Propulsion, Dual-Fuel Engines, RCCI, Combustion, marine engines

Year of the publication

2026

Citation

Kim, J., Hunicz, J., & Mikulski, M. (2026). VVA-enabled Ultra-Efficient RCCI Combustion Development in a Medium Speed Marine Engine Platform. Presented at the 9th Rostock Large Engine Symposium, Rostock, Germany, 13–14 October 2026. https://cleanpropulsion.org/wp-content/uploads/2026/10/RGMT26-Poster-KIM-UVA.pdf

Language

English

Related to:

Abstract

Background & motivation
Reactivity controlled compression ignition (RCCI), dual-fuel concept, achieves high thermal
efficiency (~55%) & ultra-low NOX and Soot and adapts various low or zero carbon fuels
Challenges: limited-load range, combustion stability, excessive hydrocarbon emissions  limit
efficient RCCI operations
Variable valve actuation (VVA) addresses these challenges by flexibly regulating in-
cylinder thermodynamic and mixing conditions [1]  unlock a broader operating window of
ultra-efficient RCCI combustion [2]
However, VVA’s potential has not been fully investigated in the marine engine platform
(efficient turbocharging system and high thermal inertia) + VVA significantly increases
calibration and optimization complexity.