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.

Feeding young animals is a very important stage during their growing-up period, but in order to provide them with essential nutrients, they are fed with liquid feeds, whole milk substitute in particular (WMS). The technique for reconstituting WMS consists of dissolving it in water followed by mixing, but it is significant to follow the cooking recipe strictly, so it is necessary to develop a system with a feeding (dosing) device that will make it possible to solve this problem. Theoretical and experimental studies of the feeding device have been conducted in order to optimize the technological process of mixing liquid feed. Theoretically, the quality of determining the mixture during dosing was established for the purpose of further research. The influence of the design and technological parameters of the feeding device was experimentally studied, and its efficiency was evaluated. It was found that as the inclination angle α increases from 67,50 to 700, the rotation speed n being from 850 to 1500 minE−1, the maximum probability of staying in the tolerance field ΔP=96% is reached, and feed discharge Q ranges from 540 to 660 kg hE−1. The research makes it possible to develop a feeding device at the design stage, meeting the requirements of the recipe, having high discharge rates and the lowest energy consumption.

Feeding young animals is a very important stage during their growing-up period, but in order to provide them with essential nutrients, they are fed with liquid feeds, whole milk substitute in particular (WMS). The technique for reconstituting WMS consists of dissolving it in water followed by mixing, but it is significant to follow the cooking recipe strictly, so it is necessary to develop a system with a feeding (dosing) device that will make it possible to solve this problem. Theoretical and experimental studies of the feeding device have been conducted in order to optimize the technological process of mixing liquid feed. Theoretically, the quality of determining the mixture during dosing was established for the purpose of further research. The influence of the design and technological parameters of the feeding device was experimentally studied, and its efficiency was evaluated. It was found that as the inclination angle α increases from 67,5⁰ to 70⁰, the rotation speed n being from 850 to 1500 min⁻¹, the maximum probability of staying in the tolerance field ΔP=96% is reached, and feed discharge Q ranges from 540 to 660 kg h⁻¹. The research makes it possible to develop a feeding device at the design stage, meeting the requirements of the recipe, having high discharge rates and the lowest energy consumption.