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Numeric modelling of fumes flow in exhaust manifold of the combustion engine

100%

Andrych M. , Sitnik L. J. , Tkaczyk M. , Walkowiak W.

Journal of KONES

2014

tom Vol. 21, No. 4

9--14

In the paper there is presented the methodology of researches as well as the numeric researches results, which aim is the analysis of fumes flow parameters in the exhaust manifold in the diesel engine, particularly the velocity, the temperatures and the turbulence of gas. It has been presented that the research methodology depending on three dimensional model of air flow in the outlet systems with the application of standard numeric methods based on the principles of conservation of: mass, energy and momentum can be the way of researches. The model may be to be the basis for performing changes in geometry of outlet system concerning minimizing the flow losses and shaping the field of velocity. The model enables of calculations of outlet system of internal combustion engines on the stage of its construction. Results show that the numerical simulations methods are one of the possible to use for achievements of investigations low costs, especially that the hardware engine parts must be not prepared. Inter alia, complete model of exhaust manifold, model of fluid volume fitting in the manifold with the numbers of ducting, the grid with applied edge conditions, linear outline of static pressure on the walls of exhaust manifold, total pressure, tension, distribution of total temperature, distribution of fluid velocity on the walls, turbulence intensity are presented in the paper.

Influence of exhaust manifold modification on engine power

75%

Bober B. , Andrych-Zalewska M. , Boguś P.

Combustion Engines

2024

tom R. 63, nr 1

54--65

The article deals with the subject of the impact of an exhaust system on the power of the internal combustion engine. In particular the article shows the possibility of increasing the power of the gasoline drive unit, interfering only with an exhaust system. The purpose of the tests carried out is to compare the results of measurements from the chassis dynamometer before and after the modification, and additionally to perform simulations for the key parts of the system in terms of shaping the power and torque curves. The analysis includes a simulation model of the exhaust gas flow through the serial manifold and also the sport manifold, especially the pressure distribution and the course of the velocity vectors at the characteristic points of the element. Before obtaining the final results of power measurements on the sport units, the roughness of the steel from which the collectors were made was also measured. The final stage is the measurement of power on the new exhaust system. The obtained results of power measurements and simulations were presented in the form of a summary, which focused on the impact of individual fluid mechanics phenomena on the formation of power and torque curves and detailed the advantage of the new exhaust system in comparison with the factory system in terms of increasing the performance of the tested vehicle.

Heat Treatment of the SiMo Iron Castings - Case Study in the Automotive Foundry

63%

Cygan B. , Stawarz M. , Jezierski J.

Archives of Foundry Engineering

2018

tom Vol. 18, iss. 4

103--109

Silicon – molybdenum cast iron commonly called SiMo due to its unique properties has becoming more and more interesting engineering material. The history and development of this alloy is relatively long but, due to the significant difficulties during the manufacturing process resulting in the lower final quality than expected, it has not been applied to often in practice. The biggest challenge is its brittleness as a result of the carbides precipitations. During last few years, thanks to the many important researches made and the general foundry technology development, the interest in SiMo iron has been rapidly growing, especially for the castings for heavy duty applications like corrosion, high temperature and wear abrasion resistant parts. In the article the heat treatment attempts to improve the microstructure of SiMo castings has been presented. The goal was to destroy or at least to refine and uniformly distribute the carbides precipitations to improve mechanical properties of the exhaust manifold castings for the cars. The experiments were carried out for the alloy contains approx. 4% Si, 1% Mo and 3.2%C. The range of the research included: hardness measuring, standard mechanical properties and microstructure for as-cast state and after that the subsequent heat treatment process with another properties check. The result of the heat treatment was the elimination of pearlite from the metal matrix. Moreover, the changes of the carbide molybdenum – rich phase morphology were observed. The dispersion of the carbides precipitations in the carbides area was observed. The experiments proved the possibility to control the microstructure and the mechanical properties of the SiMo castings by means of heat treatment but only to some extent.