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Advisor(s)
Abstract(s)
A implementação de sistemas de sobrealimentação em motores de combustão interna já
é estudada há várias décadas. A necessidade de aumentar potência juntamente com a de
reduzir consumos tornaram esta procura bastante apelativa. No entanto, durante muitos
anos, os sistemas de sobrealimentação foram projetados e construídos com base em
conhecimento empírico. Dado ao aprofundamento do conhecimento em aerodinâmica e
mecânica praticados hoje em dia, é possível prever o desempenho de turbomáquinas em
função de parâmetros específicos e otimizar o conceito antes da fase de construção, de
forma a tornar os sistemas mais seguro (e eficiente).
Este projeto foi desenvolvido com o propósito de verificar se a implementação de um
sistema de sobrealimentação de pequenas dimensões a um motor de combustão interna
é uma opção viável. Para isso, foi construído um banco de ensaios para teste de um motor
Honda GX50, um monocilíndrico a 4 tempos, ao qual foi acoplado mecanicamente um
compressor centrífugo de pequenas dimensões ligado através de duas polias. Foram
usadas polias de diferentes dimensões com a finalidade de comparar resultados e
perceber a influência no desempenho do motor estudado. O desempenho do motor foi
quantificado pelos valores de binário, potência, pressão estática e consumo específico de
cada caso ensaiado.
Por fim e com base nos resultados obtidos, determinou-se que o sistema de
sobrealimentação aumenta ligeiramente o desempenho do motor, aumentando os seus
valores de binário e potência, e diminuindo os valores de consumo específico, mas apesar
do compressor centrífugo conseguir injetar mais ar para a admissão do motor, verificado
pelo aumento da pressão estática do sistema, evidencia-se que o sistema não é uma
solução muito viável.
The implementation of supercharging systems in internal combustion engines has been studied for several decades. The need to increase power output together with the need to reduce consumption have made this pursuit very appealing. However, for many years supercharging systems were designed and built based on empirical knowledge. Given the depth of knowledge in aerodynamics and mechanics practiced today, it is possible to predict turbomachinery performance as a function of specific parameters and optimize the concept before the construction phase in order to make the systems safer (and more efficient). This project was developed with the purpose of verifying whether the implementation of a small supercharging system to an internal combustion engine is a viable option. For this purpose, a test bench was built to test a Honda GX50 engine, a single-cylinder 4- stroke, to which a small centrifugal compressor was mechanically coupled connected through two pulleys. Pulleys of different dimensions were used in order to compare results and understand the influence on the performance of the engine studied. The engine performance was quantified by the values of torque, power, static pressure and specific consumption for each case tested. Finally, and based on the results obtained, it was determined that the supercharging system slightly increases the engine performance, increasing its torque and power values, and decreasing the specific consumption values, but despite the centrifugal compressor being able to inject more air into the engine intake, verified by the increase of the static pressure of the system, it is evident that the system is not a very viable solution.
The implementation of supercharging systems in internal combustion engines has been studied for several decades. The need to increase power output together with the need to reduce consumption have made this pursuit very appealing. However, for many years supercharging systems were designed and built based on empirical knowledge. Given the depth of knowledge in aerodynamics and mechanics practiced today, it is possible to predict turbomachinery performance as a function of specific parameters and optimize the concept before the construction phase in order to make the systems safer (and more efficient). This project was developed with the purpose of verifying whether the implementation of a small supercharging system to an internal combustion engine is a viable option. For this purpose, a test bench was built to test a Honda GX50 engine, a single-cylinder 4- stroke, to which a small centrifugal compressor was mechanically coupled connected through two pulleys. Pulleys of different dimensions were used in order to compare results and understand the influence on the performance of the engine studied. The engine performance was quantified by the values of torque, power, static pressure and specific consumption for each case tested. Finally, and based on the results obtained, it was determined that the supercharging system slightly increases the engine performance, increasing its torque and power values, and decreasing the specific consumption values, but despite the centrifugal compressor being able to inject more air into the engine intake, verified by the increase of the static pressure of the system, it is evident that the system is not a very viable solution.
Description
Keywords
Binário Compressor Centrífugo Consumo Específico Difusor Potência Média Pressão Estática Rotor Sobrealimentação