Method of selecting optimal engine characteristics for minimum injector deposits

Abstract

A method of selecting at least one optimal combination of engine or fuel injector characteristics that minimize injector tip deposit formation of one or more selected internal combustion engine and fuel injector. The combination can be different engines with different injectors or the same engine or the same injector but with different characteristics for the engine and injector. For each combination selected, the method involves generating at least two maps different maps that are analyzed to determine whether a particular engine with the particular fuel injector has a tendency to promote injector tip deposits formation. The first map is a map of the range of injector tip temperatures of a particular engine and injector combination. The first map is a rough indicator of a tendency towards combustion deposits. The second map is an engine characterization map that correlates testing conditions to actual combustion deposits formation. Each engine and injector being tested is one combination that can be evaluated by both the first and the second maps. Various combinations of engine and injector can be tested. Alternatively, different combinations can be achieved when the engine or injector characteristics for a particular combination of engine and injector are altered. The engine or injector characteristics can be different engines, different fuel injectors, an engine operating in a stratified charge operational mode or homogeneous charge operational mode, operating cycles of the engine, injector tip position proximate the combustion chamber, insulated and non-insulated injector tip, material composition of the injector tip, coating or plating on the injector tip, surface polishing of the injector tip; fuel type, fuel additives, geometry of the injector:seat, geometry of the needle, the seat sac volume, reduced bounce injector (by controlling the impact velocity of the injector tip on the seat during a closing of the injector), increased fuel flow, increased fuel flow and fuel pressure or air/fuel ratio.

Dependencies are inferred from the claim text.