This paper investigates the effect of separated exhaust expansion chamber parameters on pressure oscillations in spark-ignited internal combustion (IC) gasoline engines. It is known that exhaust expansion chambers are becoming increasingly more popular among both – original equipment (OE) and aftermarket equipment (AE) exhaust system manufacturers for performance-oriented motorcycles equipped with mainly single cylinder engines, but the companies are reluctant to reveal any detailed principles of operation of the mentioned expansion chambers. The subject of this research is the type of expansion chamber (separate) as used on performance-oriented motorcycles, particularly its’ effect on exhaust pressure pulsations as different chamber volumes, locations and passage sizes are tested. Time-dependent computational fluid dynamics (CFD) analysis was carried out in Solidworks Flow Simulation environment on a simplified exhaust header pipe model imitating engine operation at full load and steady speed. Honda CRF450R motorcycle engine was used as the example and fully defined using a 1D engine performance calculator software to determine the combustion chamber pressure and exhaust valve lift at any given crankshaft position. Volume flow rate of exhaust gasses at the header pipe inlet was calculated based on engine parameters and operating speed. The average pressure values with respect to physical time were measured and graphed across the header pipe inlet cross-section. Eight different header pipe and exhaust expansion chamber combinations were modelled, tested, and results compared at low, medium and high engine speeds. It was found that the presence of exhaust expansion chamber tends to dampen the amplitude and decrease the frequency of pressure oscillations generated at the opening of the exhaust valve(s). Observations show that the addition of an expansion chamber as per design of performance-oriented motorcycles helps to decrease the negative effect of engine tuning while also dampening the positive effect.

This paper investigates the effect of separated exhaust expansion chamber parameters on pressure oscillations in spark-ignited internal combustion (IC) gasoline engines. It is known that exhaust expansion chambers are becoming increasingly more popular among both – original equipment (OE) and aftermarket equipment (AE) exhaust system manufacturers for performance-oriented motorcycles equipped with mainly single cylinder engines, but the companies are reluctant to reveal any detailed principles of operation of the mentioned expansion chambers. The subject of this research is the type of expansion chamber (separate) as used on performance-oriented motorcycles, particularly its’ effect on exhaust pressure pulsations as different chamber volumes, locations and passage sizes are tested. Time-dependent computational fluid dynamics (CFD) analysis was carried out in Solidworks Flow Simulation environment on a simplified exhaust header pipe model imitating engine operation at full load and steady speed. Honda CRF450R motorcycle engine was used as the example and fully defined using a 1D engine performance calculator software to determine the combustion chamber pressure and exhaust valve lift at any given crankshaft position. Volume flow rate of exhaust gasses at the header pipe inlet was calculated based on engine parameters and operating speed. The average pressure values with respect to physical time were measured and graphed across the header pipe inlet cross-section. Eight different header pipe and exhaust expansion chamber combinations were modelled, tested, and results compared at low, medium and high engine speeds. It was found that the presence of exhaust expansion chamber tends to dampen the amplitude and decrease the frequency of pressure oscillations generated at the opening of the exhaust valve(s). Observations show that the addition of an expansion chamber as per design of performance-oriented motorcycles helps to decrease the negative effect of engine tuning while also dampening the positive effect.

One of the mechanisms for enhancing innovative processes in the industry is the application of the concept of the “four-link spiral”. In contrast to the 3-link spiral, this model as one of the most important components includes a “society”, acting as one of the actors of innovative transformations. Firstly, it is society that is the main consumer of innovative products being created and, thereby, establishes “requirements”, forming demands for the quality and parameters of future products; secondly, society, in turn, acts as the initiator and generator of innovations, forming the so-called “social capital” necessary for the implementation of directly innovative transformations. In this scientific work, the problems of the formation of a “smart specialization” strategy for the innovative development of the industrial sector of the national economic system based on the application of the four-link spiral concept are investigated. A system of quantitative indicators for assessing the innovative level of industrial development is presented. The experience of introducing the concept of a four-link spiral as a mechanism of innovative development of industry (on the example of the Republic of Belarus and the Russian Federation) is given. The aim of the article is to describe innovation processes in the Russian Federation and the Republic of Belarus and to develop an innovation transfer model.

One of the mechanisms for enhancing innovative processes in the industry is the application of the concept of the “four-link spiral”. In contrast to the 3-link spiral, this model as one of the most important components includes a “society”, acting as one of the actors of innovative transformations. Firstly, it is society that is the main consumer of innovative products being created and, thereby, establishes “requirements”, forming demands for the quality and parameters of future products; secondly, society, in turn, acts as the initiator and generator of innovations, forming the so-called “social capital” necessary for the implementation of directly innovative transformations. In this scientific work, the problems of the formation of a “smart specialization” strategy for the innovative development of the industrial sector of the national economic system based on the application of the four-link spiral concept are investigated. A system of quantitative indicators for assessing the innovative level of industrial development is presented. The experience of introducing the concept of a four-link spiral as a mechanism of innovative development of industry (on the example of the Republic of Belarus and the Russian Federation) is given. The aim of the article is to describe innovation processes in the Russian Federation and the Republic of Belarus and to develop an innovation transfer model.