Search Results

The experiments were made on the direct injection combustion system consisting of the shallow W - type combustion chamber and the intake port with shorter passage length and weaker swirl intensity, which leads to lower requirements for manufacturing the engine cylinder head, in a small bore single - cylinder diesel engine. Test results are satisfactory. Based on performence characteristics and heat release rate curves measured in different behaviour under various matches of combustion chamber design and fuel injection system, authors have discussed each effect of design parameters on engine performances and combustion characteristics, and put forward the key points for optimization of the combustion system match.

In this paper, on the basis of great test data, the heat exchange characteristics of the water cooling and radiating system for the Star-Steyr WD615 diesel engine series are analyzed in detail. From the characteristic of heat releasing of engine and the measured discharge curves of water pump and fan, the coefficient K of heat transfer and the radiating capability for the radiator of Model WD615.67 diesel engine are exactly computed. The computing results are conformable with the practical inspection of the diesel engine. The calculation of the radiator indicates that its heat transfer resistance comes mostly from the resistance of the water tube and the cooling rib to air. Therefore in the view of authors, the key to improve the heat radiating capability of a radiator is to decrease the heat transfer resistance of the radiator on the air side.

The unsteady gas flow phenomenon in the gas exchanging process for a small two-stroke petrol engine with crankcase-scavenge is very complex. And the effect of its flow state on engine performances is extremely sensitive. In this paper, the effect of the intake and exhaust system for several small twostroke petrol engines on engine performances is investigated through the engine bench test. The airfuel equivalence ratios of engine carburators are statistically analyzed on the basis of a many of Measured data under different operating behaviours. Experimental investigation has indicated that the unsteady gas flow in the intake and exhaust system has influence on the characteristic of airfuel ratio, therefore, in the same time of utilizing the gas dynamic effect of unsteady gas flow for improving the engine performances, the carburator characteristic of airfuel ratio should be modified.

In this paper, computational non-steady gas flow process simulating of intake system of Model SD2100 diesel engine have been made by using the characteristic method. In the meantime, intake air pressure waves in the engine intake pipe under different engine rotative speeds have been measured on the engine test rig with an inverted drive, and exploratory investigation conducted into the influence of intake pipe length, design of pipe branch, air fitter and other factors on the charging efficiency and intake air pressure wave. The computed results agree mainly with the measured data. Because of having used the design of two-branch short pipes equal-length in intake system of SD2100 diesel engine, the interaction phenomenon of intake air pressure waves of two cylinders each other is found out both in test and computation, thereby, the intake air chargings into two cylinders are unequal.

It is simple and advisable as well as efficacious to improve the dynamic and economic properties of two-stroke motorcycle petrol engine by means of exhaust dynamic effect. In this paper, the exhaust pipe design method and the effect of some exhaust system factors on the exhaust dynamic effect are researched into by test for the exhaust systems of the two models of motorcycle engines. Under several operating conditions, exhaust pressure waves are measured respectively at the different points on the exhaust pipes of variously designed sizes. Having analysed the measured exhaust pressure waves and the results simulatively calculated, the relative problems to reasonablely utilize the exhaust dynamic effect of two-stroke motorcycle petrol engines are discussed in some detail.