Flex-fuel engines are an important national development that guarantees decision-making power and operating safety, with ethanol, gasoline or their mixtures, regardless of seasonal price variations and international quotations, both for oil and sugar. However, the compromise solution adopted for use with both fuels causes the engines to operate with low efficiency compared to the potential of each fuel. Normally, the main limiting factor for the increase in efficiency is the operation severely limited by detonation (knock), when operating with gasoline, making parameters such as the air/fuel ratio and compression ratio limited to maximum values for gasoline, but which are still too low for combustion with ethanol. Low operating efficiency is a problem with both fuels. It gets worse, however, with ethanol, due to its lower calorific value, leading to a high volumetric consumption of fuel. A solution that would enhance efficiency gains with both fuels and, particularly, with ethanol, would be the use of high and ultra-high pressure direct injection. The high pressure injection allows the adoption of late fuel injection in the compression phase, making it practically only with air, which inhibits the occurrence of self-ignition; in addition to allowing higher compression ratios. Air-only intake and compression also raises the specific heat ratio, leading to even greater thermodynamic gains. On the other hand, the ultra-high pressure injection promotes a highly turbulent spray with high momentum, which allows to condition the flow to enhance the mixture preparation and accelerate combustion, further benefiting the thermodynamic cycle, at the same time in which the potential emissions of particulate matter are minimized. By adding complementary technologies, such as Miller/Atkinson cycles, VVT; de-throttling; variation of the effective compression ratio, water injection, fuel heating, etc., the benefits become even more expressive. This project, therefore, aims to develop, study and test strategies related to high and ultra-high pressure injection that allow the improvement of flex-fuel engines for application in conventional and hybrid vehicles. The project takes place in cooperation with the companies: AVL SOUTH AMÉRICA LTDA, MARELLI SISTEMAS AUTOMOTIVOS INDÚSTRIA E COMÉRCIO BRASIL LTDA., FCA FIAT CHRYSLER AUTOMÓVEIS BRASIL LTDA., GENERAL MOTORS DO BRASIL LTDA., and the ICTs ITA, IMT, UNICAMP, UFSM, USP , with each ICT having its associated coordinator. PARTNERSHIP AGREEMENT 27192.01.01/2020.05-00 FOR RESEARCH, DEVELOPMENT AND INNOVATION – RD&I. Project approved in Call 01/2020 of Line V (BIOFUELS, VEHICLE SAFETY AND PROPULSION ALTERNATIVE TO COMBUSTION) with resources from the Rota 2030 Program. doctor Pedro Lacava (ITA) The institutional coordination of USP and Prof. doctor Guenther Carlos Krieger Filho.
Participants: Fernando Luiz Sacomano Filho – Member / Antonio Luiz Pacífico – Member / Guenther Carlos Krieger Filho – Member / Pedro Teixeira Lacava – Coordinator / Mario Eduardo Santos Martins – Member / Rogério Gonçalves dos Santos – Member.