The ICE-GA (Italian Combustion Experiment for Green Air), as follow-on to the FLEX (FLame EXtinguishment) experiments, has the objective of studying the combustion of binary mixtures, emulating real fuels rich in renewable green components, in microgravity conditions. To this aim, droplets composed of n-heptane/ethanol and n-decane/1-hexanol will be studied by using the Combustion Integrated Rack (CIR) and the associated Multi-user Droplet Combustion Apparatus (MDCA) that is currently in-orbit aboard the International Space Station (ISS). The experiment will investigate the combustion of fiber supported droplets ranging from 1mm to 4 mm at different pressures and oxygen concentration. The pressure will be varied from below atmospheric pressure to 0.3 MPa. The experimentation will be carried out in synthetic atmosphere whose composition will be changed from oxygen-rich conditions down to flammability limit. n-decane and n-heptane are two alkane fuels with high sooting tendency. The low sooting tendency of the alcohols will lighten the soot shell formed around the droplet by the combustion of n-alkane fuels. This should facilitate the study of the burning of droplets formed with the mixture. The analysis of the reduction of the droplet diameter permits also the study of the non-ideal behaviour of the mixture. n-decane and n-heptane represent good surrogates of aviation fuels and diesel fuels, respectively. Thus it is of particular interest to study their heating, vaporization and combustion when mixed with high concentrations of bio-alcohols. Both ethanol and hexanol can be in fact considered as drop-in-fuels derived from non-food biomasses (cellulose, hemicellulose, lignin, etc.) by means third but also fourth generation transformation processes. The FLEX-ICE-GA experiment will provide systematic experimental data on the interaction of sooting and non-sooting fuels in the combustion of an equal binary mixture of the two. The data from the experiments include details of the droplet diameter, flame dynamics from both OH* chemiluminescence and standard color images and also soot and flame temperatures. The paper will report the first analysis of the experimental data acquired during the testing campaign carried out on the ISS during the expeditions 35/36 and 37/38.
Microgravity Combustion of Isolated Binary Alcohol/n-Alkane Droplets
P Massoli;R Calabria;
2013
Abstract
The ICE-GA (Italian Combustion Experiment for Green Air), as follow-on to the FLEX (FLame EXtinguishment) experiments, has the objective of studying the combustion of binary mixtures, emulating real fuels rich in renewable green components, in microgravity conditions. To this aim, droplets composed of n-heptane/ethanol and n-decane/1-hexanol will be studied by using the Combustion Integrated Rack (CIR) and the associated Multi-user Droplet Combustion Apparatus (MDCA) that is currently in-orbit aboard the International Space Station (ISS). The experiment will investigate the combustion of fiber supported droplets ranging from 1mm to 4 mm at different pressures and oxygen concentration. The pressure will be varied from below atmospheric pressure to 0.3 MPa. The experimentation will be carried out in synthetic atmosphere whose composition will be changed from oxygen-rich conditions down to flammability limit. n-decane and n-heptane are two alkane fuels with high sooting tendency. The low sooting tendency of the alcohols will lighten the soot shell formed around the droplet by the combustion of n-alkane fuels. This should facilitate the study of the burning of droplets formed with the mixture. The analysis of the reduction of the droplet diameter permits also the study of the non-ideal behaviour of the mixture. n-decane and n-heptane represent good surrogates of aviation fuels and diesel fuels, respectively. Thus it is of particular interest to study their heating, vaporization and combustion when mixed with high concentrations of bio-alcohols. Both ethanol and hexanol can be in fact considered as drop-in-fuels derived from non-food biomasses (cellulose, hemicellulose, lignin, etc.) by means third but also fourth generation transformation processes. The FLEX-ICE-GA experiment will provide systematic experimental data on the interaction of sooting and non-sooting fuels in the combustion of an equal binary mixture of the two. The data from the experiments include details of the droplet diameter, flame dynamics from both OH* chemiluminescence and standard color images and also soot and flame temperatures. The paper will report the first analysis of the experimental data acquired during the testing campaign carried out on the ISS during the expeditions 35/36 and 37/38.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
