Using multiple ignition sites and pressure sensing devices to determine the effect of air-fuel equivalence ratio on the morphology of knocking combustion
2022-01-0524
03/29/2022
- Event
- Content
- Knocking combustion inherently presents an interaction between main flame front and end gas autoignition. Conventionally, it generates a high amplitude pressure wave traveling across the chamber, can be responsible for reducing the performance of the engine and can cause heavy damage to engine components. In order to study the phenomenon in a controllable way, experiments were performed on a specialized single-cylinder research engine fitted with a liner equipped with four equi-spaced spark plugs in the side so as to propagate various flames from those locations, and hence achieve more controlled knock events. In addition, six pressure transducers were employed at distinct locations to precisely record details of the autoignition event by monitoring pressure oscillations, and with them combustion characteristics and knock intensity. Four of the six transducers were mounted on the circumference of the liner (each next to one of the spark plugs), one was placed at the center of the cylinder head, and one at a slight offset from the center of cylinder head. Various spark ignition approaches such as the spark timing (ST), the number of ignition sites, and the location of the active spark plugs were applied to analyze the knock attributes for different ignition strategies. Since knock occurrence depends strongly on the relative air-fuel ratio (λ), this paper describes the effect of rich and lean conditions on knock instigation coupled with firing multiple spark ignition sites. The experimental results reveal that using multiple spark-ignition could promote knock intensity, advance the start of auto-ignition and introduce more acoustic resonance modes in the gas vibration in the cylinder
- Citation
- Uddeen, K., Shi, H., Tang, Q., and Turner, J., "Using multiple ignition sites and pressure sensing devices to determine the effect of air-fuel equivalence ratio on the morphology of knocking combustion ," SAE Technical Paper 2022-01-0524, 2022, .