A Numerical and Experimental Investigation on Different Strategies to Evaluate Heat Release Rate and Performance of a Passive Pre-Chamber Ignition System
2022-01-0458
03/29/2022
- Event
- Content
- Passive pre-chamber ignition concept has been proven as an excellent solution to increase the combustion velocity and to allow the use of different strategies that are able to reduce pollutant emissions of internal combustion engines. Although pre-chamber combustion concept has been extensively studied, the evaluation of the heat release rate (HRR) inside the pre-chamber and its effects on the performance of the engine has not been widely investigated. In this work, newly designed passive pre-chambers with different nozzle-hole patterns, featuring combinations of radial and axial holes, were experimentally investigated in a 4-stroke single-cylinder light-duty optical engine. All the pre-chambers analyzed had a narrow throat geometry to increase the velocity of the ejected jets. An inductive and a nanosecond spark ignition systems were implemented. The evolution of the pressure during the engine cycle in the main and pre-chamber was measured at different values of the equivalence ratio, by means of dedicated pressure transducers. High-speed hydroxyl radical (OH*) chemiluminescence images were collected to investigate the combustion process in the main chamber. From the measured pressure profiles, the experimental heat release rate inside the main and pre-chambers was calculated and utilized as input in two different 1D models based on the GT-Power software. The first model implemented the heat release rate calculated from experiments for both chambers. The second model featured only the experimental HRR for the main chamber, while the pre-chamber heat release rate was numerically evaluated. The main differences between these two models were evaluated in terms of pre-chamber jets momentum and penetration, and relevant pre-chamber parameters, such as the rate of heat fluxes to the wall or temperature evolution. Results show discrepancies between the models in the analyzed parameters which affect the estimated performances of the engine and highlighting the sensitivity of the simulation results to a proper inputs selection.
- Citation
- Martinez-Hernandiz, P., Di Sabatino, F., Novella, R., and Ekoto, I., "A Numerical and Experimental Investigation on Different Strategies to Evaluate Heat Release Rate and Performance of a Passive Pre-Chamber Ignition System," SAE Technical Paper 2022-01-0458, 2022, .