Research of Nature of Interaction of Fuel Spray with Wall of Combustion Chamber of Overload Diesel Engine on Unique ‘Injection’ Research Installation

This paper provides the results of experimental research of visual development of diesel fuel spray and its interaction with the wall of combustion chamber for the regimes of an overloaded transport diesel engine. Studies are performed in a constant volume chamber using a unique ‘Injection’ research installation with colour high-speed video recording of the injection process. The analysis results show that the initial profile of the piston combustion chamber does not provide free development of the reverse-flow zone of the fuel spray after its collision with the combustion chamber wall, so the initial profile needs to be changed. To prove the efficiency of such measures, motor tests were performed for a one-cylinder diesel engine with the cylinder’s diameter of 150 mm, piston stroke of 160 mm, and also equipped with an air compressor at crankshaft speed of 2000 min⁻¹. Two variants of piston structures, with an initial combustion chamber and a test one, were studied. The results of experimental research for a one-cylinder diesel engine show that the piston with the test combustion chamber in the whole studied range provides the improvement of fuel efficiency by 3–5 g/kW * h as compared to the initial combustion chamber without increasing of thermal and mechanical intensity which confirms the results of non-motor research.