Pedro Magalhães de Oliveira.

Combustion is the fast heat-producing reaction between hydrocarbon fuel and oxygen. While CO2 is often the focus, NOx (a family of compounds including nitrogen dioxide or NO2) and particulates are also emitted by modern jet engines. NO2 is an important pollutant on its own, and it participates in atmospheric ozone and acid rain chemistry. While new combustion processes that minimise NOx production from industrial burners have been developed, they have not yet been applied to the combustion of kerosene in jet engines. Reducing particulate matter emission from kerosene or new synthetic fuels is also important. The EU-funded LEAFINNOX project covers these gaps through a combination of experiments and modelling that provide new combustion concepts minimising both NOx and particulate emissions.

Clean Sky 2 is a European research programme aimed at developing leading-edge clean air aviation technologies to reduce greenhouse gas emissions and noise levels produced by aircraft. Currently, the demonstrator programme is developing and testing very high bypass ratio (VHBR) geared turbofan technologies that are expected to improve fuel efficiency by more than 25 . The EU-funded PROTEUS project will undertake research and development of tools that can predict the idle and sub-idle performance and operability of VHBR geared turbofan engines. To do so, it will perform detailed component aerodynamic performance characterisation of validated high-order methods, using high-fidelity models and simulations along with validation against experimental data.

Low-emission gas turbines are confronted with unsteady combustion problems often only discovered late into development or in service because our scientific and understanding is insufficient to predict them at the design stage. For reasons of cost and simplicity, we have been trying to solve unsteady combustion problems by studying them in single (or multiple) sectors. The lack of success of this approach is a striking gap in our community and is hindering innovation. ANNULIGhT will break this paradigm by bringing together academic and industry leaders to provide a new generation of engineers with an innovative, structured, multi-disciplinary training programme combining cutting-edge theory, computational and experimental methods that exclusively focuses on annular combustion chambers as found in real gas turbines.

The development of lean-burn gas turbine combustors, which will lead to a reduction of emissions from aviation, relies upon resolving significant problems associated with this new technology, namely the emergence of combustion-induced pressure oscillations that can damage the engine, and the danger of flame extinction, which may not allow the full benefits of lean-burn to be realised. Apart from their very significant practical importance, these phenomena are very challenging scientifically and a complete theoretical treatment is not available at present.In this proposal, simulation tools for advanced cooling methods, for thermoacoustics, and for flame extinction will be developed, enabled by recent theoretical, computational, and experimental developments. These tools will be based on low-order models and more complex Computational Fluid Dynamics methods, both validated against focused experiments in single-sector, multi-sector, and full annular geometries. The results will assist engine manufacturers assess ideas and designs at low TRL levels, which will decrease the development time and the high cost associated with testing at high TRL.

O conhecimento de propriedades termofísicas e de processos de transporte envolvendo o dióxido de carbono (CO2) a altas pressões e altas temperaturas será vital para o desenvolver e otimizar sistemas de produção e para a garantia do escoamento do óleo da região do pré-sal. O objetivo deste projeto é a caracterização teórica e experimental do comportamento termodinâmico (equilíbrio de fases, limites de miscibilidade) e das propriedades termofísicas de misturas de óleos e dióxido de carbono (CO2) a altas pressões e altas temperaturas (até 400 bar e 200oC). Dentre as propriedades avaliadas destacam-se a densidade, a viscosidade, a tensão superficial, o ângulo de contato, a condutividade térmica, o calor específico a pressão constante e a difusividade mássica. Propriedades elétricas da mistura, como a constante dielétrica e a permissividade relativa também serão avaliadas experimentalmente.

O projeto, vinculado à Rede Temática CENPES/Petrobras em Escoamentos Multifásicos em Dutos, visa a implantação de uma estrutura de laboratório para a investigação de fenômenos de mudança de fase e escoamentos multifásicos envolvendo misturas. O principal objetivo da pesquisa é o desenvolvimento do conhecimento sobre a utilização de técnicas de medições avançadas de escoamentos (como imagem a alta velocidade, PIV, LDA) em situações envolvendo mudança de fase. Para tal, será construído um aparato experimental para simular a vaporização por redução de pressão (flashing) em escoamentos em dutos e singularidades. Modelos teóricos e numéricos desenvolvidos pelo grupo serão utilizados para corroborar os dados experimentais..

O fenômeno de ?Liquid Loading? em poços de gás é o foco principal deste projeto. Tal fenômeno, que é prejudicial à produção e acelera o envelhecimento do poço, é resultado da formação e acúmulo de gás condensado ao longo de sua vida útil. A pesquisa consiste no desenvolvimento de modelos matemáticos para simular o transporte de gás e condensado ao longo do poço, assim como os mecanismos físicos relevantes e cenários que propiciem a ocorrência de ?Liquid Loading?. O projeto, vinculado à Rede Temática da Petrobras em Poços Maduros, conta com a colaboração acadêmica da Texas AM University, Imperial College London e Universitá di Roma ?La Sapienza?.

NOx Production in Partially Pre-Vaporized Droplet and Spray Systems under Microgravity