Browse Topic: Combustion and combustion processes
The demand for electrified vehicles has been increasing over the last few years, near to 180 thousand units were sold only in 2024, which represented around 7% of total sales of this type of vehicle in Brazil. By the year 2030, it is expected that at least 40% of sales volume will be electrified vehicles, considering mild hybrids. These results show that vehicle manufacturers are moving towards electrification and reducing carbon emission rates. Different levels of electrification are applied in their portfolio: from mild hybrid or rechargeable vehicles to fully electric vehicles. When analyzing the number of components in each automotive system, it is possible to notice a huge reduction. Electric vehicles have 90% fewer moving parts in the engine than combustion vehicles. In brake systems, the reduction can be up to 20% in hybrid and electric vehicles, which can use the same solutions. This paper aims to present the changes in the sets of braking components from combustion vehicles to
The activation of the fuel injector affects both engine performance and pollutant emissions. However, the automotive industry restricts access to information regarding the circuits and control strategies used in its vehicles. One way to optimize fuel injections is using piezoelectric injectors. These injectors utilize crystals that expand or contract when subjected to an electric current, moving the injector needle. They offer a response time up to four times faster than solenoid-type injectors and allow for multiple injections per combustion cycle. These characteristics result in higher combustion efficiency, reduced emissions, and lower noise levels, making piezoelectric injectors widely used in next-generation engines, where stricter emission and efficiency standards are required. This study aims to design a drive circuit for piezoelectric injectors in a common rail system, intended for use in a diesel injector test bench. Experimental measurement of voltage was obtained from an
With the implementation of increasingly stringent regulations for pollutant emissions, such as Proconve L8 [1], which requires a 37% reduction in NOx and non-methane organic gases (NMOG) emissions for light passenger vehicles compared to previous regulations, the automotive engineering community is constantly evolving to develop prediction models that are capable of predicting the performance of Internal Combustion Engines (ICE). With this, the society search solutions to increase fuel conversion efficiency and reduce fuel emissions. In a special case, related to the study of the turbulent jet ignition (TJI) engine, there was a need to develop a refined numerical model that allows for the accurate design of the ignition pre-chamber geometry. In view of this, a one-dimensional modeling was carried out in the GT-SUITE ® software, in its modeling environment for Internal Combustion Engines (ICE), GT-POWER ®, with the objective of determining its ideal volume, parameters such as internal
Flex-fueled vehicles (FFV) dominate the Brazilian market, accounting for over 75% of the national fleet. Ethanol fuel is widely used, primarily in the form of hydrated ethyl alcohol fuel (HEAF). Given the similar physicochemical properties of ethanol and methanol, fuel adulteration is a growing concern, often involving the addition of anhydrous ethanol, methanol, or even water to hydrated ethanol. These adulterants are visually imperceptible and can only be detected through analyses conducted by regulatory agencies using specialized instruments. However, they can significantly affect vehicle performance and accelerate engine component deterioration. The experiment was performed with a small displacement 3-cylinder port fuel injection flex-fuel engine on an engine test bench (dynamometer) and compared when fueled with ethanol and methanol. Data acquisition included combustion pressure, spark plug temperature, torque, air-fuel ratio, fuel flow, spark maps, and the overall effects of
As a zero-carbon fuel, ammonia has the potential to completely defossilize combustion engines. Due to the inert nitrogen present in the molecule, ammonia is difficult to ignite or burn. Even if the ammonia can be successfully ignited, combustion will be very slow and there is a risk of flame quenching, i.e. the flame going out before the ammonia-air mixture has been almost completely converted. Both the difficult flammability and the slow combustion result in high ammonia slip, which should be avoided at all costs. The engine efficiency is also greatly reduced. Safe ignition and burn-through can be achieved by drastically increasing the ignition energy and/or using a reaction accelerator such as hydrogen. The planned paper will use detailed 1D and 3D CFD calculations to show how high the potential of ammonia combustion in an internal combustion engine is when an active pre-chamber is used as the ignition system. As a result of the flame jets penetrating into the main combustion chamber
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