Influence of Injection and Flame Propagation on Combustion in Motorcycle Engine - Investigation by Visualization Technique

Abstract

Reduction of fossil fuel consumption is necessary with regards to global warming and energy security. Motorcycle has great potential to play an important role for these demands due to its light weight. Reduction of environmental impact is also an important factor as well as the fuel efficiency. Mixture formation is one of the key issues for both aspects. Port fuel injection system is getting popular due to better control ability of fuel supply than by carbureter that is still used widely due to the benefit of cost and simplicity. Port fuel injection system is widely used for automotive application in many years. Compared to automobile, motorcycle has severe limitations about cost and space. Demand for specific power is higher instead of less stringent emission regulation. Considering these differences, it is important to establish appropriate guide for motorcycle applications with regard to injector layout and injector specification to satisfy regulation for environment without deterioration of advantages. One of the most important issues is generation of wall film. It is enhanced by shorter distance between injection hole and wall against it, shorter duration to evaporate due to higher engine speed, and lower evaporation

An Experimental Study for Performance and Emissions of a Small Four-Stroke Si Engine for Modern Motorcycle

“…Therefore, new techniques have been proposed for robust fine-tuning of fuel quantities to boost engine performance and reduce emission levels. Electronically controlled fuel injection offer the prospect of realizing the fuel efficiency concept (giving the lowest fuel consumption and emissions) [9].Fuel injection allows the amount of fuel injected per cycle to be varied in response to inputs derived from sensors which define actual engine operating conditions [10]. The fuel injection system seems a promising technology as a means to supply suppressed fuel because of its high fuel delivery efficiency, enhanced fuel economy and reduced engine out emission [11][12][13][14][15][16][17][18].A fuel injector is a valve-nozzle combination that inserts a spray fuel into the air flow.…”