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Researches of influence kind of piston on some parameters of the S12-U Wola diesel engine

Jankowski A., Kołomecki J., Siemińska B.

Journal of KONES

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2012

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Vol. 19, No. 3

185-194

EN

Increased weight and greater requirements, regarding manoeuvring opportunities need extension of the power of combustion engines determining their powertrain units. In case of the family "W" engines, following developmental versions came into existence as a result of the modernization of the earlier version, among others thru the optimization of the combustion process, applying of the supercharging, as well as strengthening of the internal construction, which made it possible to carry greater thermal and mechanical loads. The subjects of the study were pistons made from composite materials of the small hysteresis of the alloy mounted on the S12-U combustion engine. In the novel construction of the piston, the outline of the overcoat was modified, the shape of the combustion chamber, the hole for the piston pin, grooves for the piston rings and shape of internal surfaces remained unchanged. A characteristic feature of the novel piston is the smaller hysteresis of the coefficient of thermal expansion composite alloy, alfa of which the pistons were made, whereas a so-called hysteresis is the difference of the coefficient alfa, which occurs during warming and piston cooling, and takes place during working of the piston in the combustion engine. The smaller hysteresis of the coefficient alfa makes the decreasing clearances between piston and cylinder possible, what has a beneficial influence on work parameters of the combustion engine, especially under conditions of partial loading of the engine. Basic parameters of the engine for the maximum torque characteristics and load characteristics are the object of the paper.

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Investigations of strength, thermal expansion and engine of novel pistons for combustion engines

Siemińska B.

Journal of KONES

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2008

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Vol. 15, No. 3

471-478

EN

Pistons of internal-combustion engines work in the conditions of high mechanical and thermal loads. The typical alloy materials applied on pistons of internal-combustion engines have inadequate parameters for such applications. It mainly refers to the fatigue strength of the mechanical and thermal character and to the thermal shocks. In relation with fact that the piston of internal-combustion engine has unsymmetrical shape, that in every case of the piston temperature increase the unequal deformations appear and stresses related with this, what causes fatigue loads of the piston structure. The paper presents special demands, which pistons of contemporary of internal-combustion engines must fulfil with respect to strength, thermal and useful properties, mirrored in the engine work parameters, like engine oil consumption, fuel consumption, noise, gas blow by to the crankcase and the emission of toxic exhaust elements, mainly hydrocarbons. One turned attention on the new material that can be used in manufacture of pistons for the internal-combustion engines, which is the carbon material. In the article the results of research for the mechanical, thermal and engine properties are submitted for the pistons manufactured from a new material. On the emphasis deserve fact, that the application of new materials permits on the obtainment of the small difference in the coefficient of linear thermal expansion during the heating and the cooling, that will bring many profitable effects of both functional and useful nature.

3

Novel engine of higher efficiency

Siemińska B., Drew J.

Journal of KONES

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2007

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Vol. 14, No. 4

409-416

EN

The idea of the new engine results that is possible increasing of the work efficiency of the engine. novel engine of higher efficiency development and the novel method of cylinder filling, piston stop study, dual heat path, piston cooling, combustion chamber pressure development in the constant volume phase, stress containment in the non moving piston, emissions with the direct injection installation. The creature of the solution consists in the realization the process of the combustion at the constant of the volume combustion chambers. It is realized with a piston stand during the period of combustion process. This permits on maximum pressure increasing and average indicated pressure. The enlargement of the efficiency is obtained, and finally - decrease of fuel consumption. Whereas at such itself average indicated pressure, the maximum decrease appears. This development's intention is to answer the question of alternate method of production of mechanical power from the expanding medium. The novel engine of higher efficiency development and novel engine of higher efficiency patents address the means and methods of exchange of spent or burned gasses for the fresh charge of air or fuel-air mixture in the two stroke configuration using the circular cross section pistons like the conventional four and two stroke engines mentioned above and the practical method of stopping the piston mid cycle that will create a constant volume combustion chamber for the duration of the combustion process.

4

A novel design of the combustion engine for improvement of the efficiency and durability

Drew J., Jankowski A., Siemińska B., Sławinski Z.

Journal of KONES

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2006

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Vol. 13, No. 4

453-466

EN

For the purpose of the improvement of the efficiency of the combustion engine, the new solution which links in the advantage of the engine with the spark-ignition and the diesel engine is proposes. The creature of the solution consists in the realization the process of the combustion at the constant of the volume combustion chambers. It is realized with a piston stand during the period of combustion process. This permits on maximum pressure increasing and average indicated pressure. Advantages of this solution are self-evident. The enlargement of the efficiency is obtained, and finally - decrease of fuel consumption. Whereas at such itself average indicated pressure, the of maximum decrease of appears. This maximum pressure decrease causes decrease of mechanical loads of most essential engine parts, for which the pistons belong. The novel design of the engine is In order to reduce the thermal loads on the piston and the negative effects of thermal shocks, the novel construction based design was proposed, where during the time when the thermal loads are the most severe, the mechanical loads are isolated from the inertial loads and the inertial loads are non existent. Besides the reduction of the thermal loads additional gains in overall efficiency were obtained as the result of the combustion process with the piston stopped. That system forms the part of United States Patent No. 6,481.393 B1. Thermal shocks are reasons for high temperature gradients occurring in materials of engine components and sets, what in turn makes for high total stresses, even at lack of mechanical loads that accelerate damage of the engine components. With reference to heterogeneous elements like bimetals and from materials with covers, temperature gradients will be considerably greater and will represent what is due to different material properties. Experimental test results of thermal shocks for heavy-duty pistons of combustion engines are presented in the paper. Temperature measurement results on the crown and the skirt of the piston during the Diesel engine operating under different conditions are presented in the paper. Temperatures on the piston surface in the area of combustion chamber change in an every working cycle and these changes grow less with frequency (engine speed) increasing.