Fundacao para a Ciencia e a Tecnologia (FCT) e Fundacao Luso-Americana para o Desenvolvimento (FL... more Fundacao para a Ciencia e a Tecnologia (FCT) e Fundacao Luso-Americana para o Desenvolvimento (FLAD) Proj. no 05/2020
The study and understanding of cooling and freezing water droplets is of paramount importance due... more The study and understanding of cooling and freezing water droplets is of paramount importance due to their influence in the decrease of aerodynamic performance on lifting surfaces. It is imperative to develop models capable of simulating the freezing processes and ice accretion effects, in order to predict with maximum efficiency freezing and avoid this phenomenon or even taking advantage of it and develop new technologies that ultimately will improve air travel. As such, this paper aims to study the cooling of a water droplet in free fall. A two-way coupling model is implemented to evaluate the influence of gas-drop and drop-gas interactions, numerically investigating the cooling of free falling droplets for different diameters and air humidity ratios. The predictions are compared with experimental and numerical data with the objective of providing insight into the degree of heat and mass transfer involved. Some correlations to account for the convection effects are introduced and are found to be in close agreement with the experimental data.info:eu-repo/semantics/publishedVersio
The Transatlantic Flights performed at 1919 proved to be a tremendous success; however, aerial na... more The Transatlantic Flights performed at 1919 proved to be a tremendous success; however, aerial navigation over ocean was based on radio equipment. Sextants were very difficult to use, and methods of calculations were quite time-consuming to provide positioning results of an aircraft at great speeds. For these reasons, the Aerial Astronavigation was considered unsuitable. 3 years later, two Portuguese airmen managed to perform the First Aerial Crossing of the South Atlantic exclusively achieved by Aerial Astronavigation in an unprecedent route precision achievement; such feat was a milestone in Aviation History, marking the debut of the sextant as a key mean for air navigation: for the first time, sextant, course corrector and methods of calculations proved their effectiveness and value for aerial navigation. Reports of the 1st South Atlantic Air Crossing [Relatórios da 1ª Travessia Aérea do Atlântico Sul] written by Coutinho and Cabral, published in 1922, were included in the International Register of the “Memory of the World” of UNESCO. After July 27, 2011, the reports were considered World Heritage [Património da Humanidade].info:eu-repo/semantics/publishedVersio
Fundacao para a Ciencia e a Tecnologia (FCT) e Fundacao Luso-Americana para o Desenvolvimento (FL... more Fundacao para a Ciencia e a Tecnologia (FCT) e Fundacao Luso-Americana para o Desenvolvimento (FLAD) Proj. no 05/2020
The study and understanding of cooling and freezing water droplets is of paramount importance due... more The study and understanding of cooling and freezing water droplets is of paramount importance due to their influence in the decrease of aerodynamic performance on lifting surfaces. It is imperative to develop models capable of simulating the freezing processes and ice accretion effects, in order to predict with maximum efficiency freezing and avoid this phenomenon or even taking advantage of it and develop new technologies that ultimately will improve air travel. As such, this paper aims to study the cooling of a water droplet in free fall. A two-way coupling model is implemented to evaluate the influence of gas-drop and drop-gas interactions, numerically investigating the cooling of free falling droplets for different diameters and air humidity ratios. The predictions are compared with experimental and numerical data with the objective of providing insight into the degree of heat and mass transfer involved. Some correlations to account for the convection effects are introduced and are found to be in close agreement with the experimental data.info:eu-repo/semantics/publishedVersio
The Transatlantic Flights performed at 1919 proved to be a tremendous success; however, aerial na... more The Transatlantic Flights performed at 1919 proved to be a tremendous success; however, aerial navigation over ocean was based on radio equipment. Sextants were very difficult to use, and methods of calculations were quite time-consuming to provide positioning results of an aircraft at great speeds. For these reasons, the Aerial Astronavigation was considered unsuitable. 3 years later, two Portuguese airmen managed to perform the First Aerial Crossing of the South Atlantic exclusively achieved by Aerial Astronavigation in an unprecedent route precision achievement; such feat was a milestone in Aviation History, marking the debut of the sextant as a key mean for air navigation: for the first time, sextant, course corrector and methods of calculations proved their effectiveness and value for aerial navigation. Reports of the 1st South Atlantic Air Crossing [Relatórios da 1ª Travessia Aérea do Atlântico Sul] written by Coutinho and Cabral, published in 1922, were included in the International Register of the “Memory of the World” of UNESCO. After July 27, 2011, the reports were considered World Heritage [Património da Humanidade].info:eu-repo/semantics/publishedVersio
Uploads
Papers by Jorge Barata