IFS OPTIMIZATION FOR JET FUEL'S SURROGATE

In the last decades, the increasing demand for air transport, both in the military and in the civil field, has led to an exponential growth of greenhouse gases emission, which are rationally thought to play an active role in climate change. One of the most important (and promising) solution proposed to counter this problem is the replacement of current fuels with less pollutant ones. Since no such adequate improvement would be achieved if the research was focused on current feedstocks, the interest is centered on renewable energy sources, whose products are the main hydrocarbons directly involved in the fuel combustion, reducing as much as possible the presence of other polluting agents. From this alarming context immediately flows the necessity to find a well founded numerical model to forecast the chemical and physical properties of hydrocarbons' surrogate, in order to validate them against the reference petroleum fuel's properties. In this regard, the collaboration between the two Universities has made possible the development of this Master Thesis, whose main aim is to find the optimal IFS for given petroleum fuel. The strategy of IFS construction is based on the direct correlation between the synthetic petroleum fuel's specifications and the hydrocarbons' model's ones and it is used to reproduce the real fuel combustion properties. The IFS is intended to include adequate fractions of four different chemical families of hydrocarbons, i.e. normal/iso-paraffins, naphthenes (also known as cycloparaffins) and aromatics. Thanks to previous studies and with an huge bibliography effort, researchers succedeed in completing a full properties table for the forty-seven hydrocarbons, which are supposed to be the starting point for future developments. Going into the specifics of this thesis, the first pages are dedicated to a general introduction of the main problem, trying to get the reader on the path of the reference topic. Then, after a brief presentation of many important civil and military fuels, paying attention to adding specific information about the reasons for their current utilization or their past dereliction, some historical kerosene models are shown, with the aim of introducing the general iter for jet fuel modelling. In the same pages, their properties are also shown in order to make the reader more aware about their general meaning (and also their normal magnitude and operative range). After a brief treatise about the main chemical and physical properties of jet fuels, the indirectly optimized MATLAB code for the IFS is introduced. It consists of three main parts, each of them dedicated to a particular output. While the first two are independent from each other, the third one leans on them, giving the IFS as direct output. Then, a second possible code is introduced. This time, the code is characterized by a robust strategy of optimization through the use of the PSO algorithm and it returns the same outputs of the previuos attempt's code. These data are the validated against a reference model, obtained from database. In the end, potential future developments are hypothesized, in order to further validate the numerical model proposed in this work. However, regardless any possible future advancement, this thesis, since supported by a broad theoretical discussion, is thought to be a valid starting point for the course of research, giving forthcoming insiders a well founded basis where to begin their work.