Combustion time of the oxygenated and non-oxygenated fuels in an Otto cycle engine

Pedro Mello,Renato Cataluña,Rosângela Da Silva,Giovanni Souza De Andrade,Fabiano Wildner

doi:10.1007/s40430-013-0094-y

Pedro Mello, Renato Cataluña + Show 3 more

Open Access

https://doi.org/10.1007/s40430-013-0094-y

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Abstract

Speed flame propagation in Otto cycle engines is one of the principal characteristics of fuel and is fundamental in defining the ignition advance. The greater the propagation speed the less the negative work required to compress the mixture before the piston reaches the top dead center and the higher the cycle’s efficiency. This paper presents experimental results of time measurements of the fuel’s ignition and the maximum pressure rating in the combustion chamber of a Cooperative Fuel Research engine specially instrumented. The combustion duration measurements of oxygenated and non-oxygenated fuels were taken as a function of the compression ratio (8:1, 10:1 and 12:1) and lambda (λ). The speed flame propagation in the combustion chamber is significantly changed with the change of the lambda different compression ratios. The VNG has a maximum in the speed flame propagation in the stoichiometric region (λ = 1.0) in all compression rates in this study. Similar behavior occurs with ethanol and gasohol, but only in compression ratio 12:1. Ethanol and gasohol have the higher rate of flame propagation for all compression ratios measured as compared to the non-oxygenated (isooctane) and oxygenated fuels (MTBE and TAEE).

Highlights

In conventional spark-ignition engines, the fuel and air pass through intake manifold into the cylinder’s, where they are mixed with the residual gas and compressed
The vehicular natural gas (VNG) has a maximum in the speed flame propagation in the stoichiometric region (k = 1.0) in all compression rates in this study
Similar behavior occurs with ethanol and gasohol, but only in compression ratio 12:1

Summary

Introduction

In conventional spark-ignition engines, the fuel and air pass through intake manifold into the cylinder’s, where they are mixed with the residual gas and compressed. Combustion is triggered by an electric discharge during compression. The flame front propagates through the air–fuel mixture until it reaches the walls of the combustion chamber, where it is extinguished. At the onset of combustion caused by the spark from the spark-plug, the speed flame propagation is small and is accompanied by a slight increase in pressure (delay time) due to combustion. The flame front increases progressively and propagates through the combustion chamber until the. (2014) 36:403–410 pressure inside the cylinder reaches its maximum after the top dead center (TDC) Eng. (2014) 36:403–410 pressure inside the cylinder reaches its maximum after the top dead center (TDC)

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Conclusion