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An experimental assessment of burning behavior of some aviation fuel and biodiesel obtained from waste oil mixture has been performed within this paper. The biodiesel was obtained from sunflower and palm waste oil (SFP) and the mixtures consisted of 10, 30 and 50% biodiesel in regular aviation fuel. The aviation fuel is a mixture of Jet A fuel + 5% Aeroshell 500 oil (called Ke) with the oil being added for turbo-engine’s lubrication. So, the used fuels were: Ke, Ke + 10% SFP, Ke + 30% SFP, Ke + 50% SFP. In first step, SFP was characterized in terms of: density, kinematic viscosity, flash and freezing points and calorific power. Also a deeper analysis was made by using FTIR for all the fuels involved in the experiments. The second step consisted of assessing the chemical reactions that occur during the burning process. Thus starting from the known elemental analysis, the air needed for a stoichiometric reaction has been calculated for each fuel mixtures. Also the resulting CO2 and water has been calculated from the reactions. The third step consisted of experimental testing the burning behavior of the above mentioned fuels on a micro turbo-engine. The used engine was Jet Cat P80® provided by Gunt Hamburg, Barsbüttel, Germany. The variation of: rpm vs. time, burning temperature vs. time and fuel debit vs. rpm are presented for starting and yield procedures. The tests have been conducted at 8 different working regimes of the engine. For each regime, an 1 min testing period was chose, during which burning temperature vs. rpm, fuel debit vs. rpm and thrust force vs. rpm were monitored. For maximum regime, only calculus for burning, thermal efficiencies and specific consumption have been made. As a main conclusion, the engine working behavior was steady throughout the entire range of rpm and for all the blends fed, thus the studied fuel blends may be considered as sustainable fuel for applications that are using micro turbo-engines with main advantages related to pollution and raw materials allowing the production of this type of fuel.

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In the present paper, a combined method of large eddy simulations for non-premixed combustion in a turbulent flow coupled with proper orthogonal decomposition of instantaneous velocity, pressure and temperature fields is developed in order to identify the effect of coherent structure and to obtain a reduced order model for control model. First we investigate the reacting flow using Large Eddy Simulations technique. This physical model is pertinent to internal flows inside the hybrid rocket motors. The turbulence-combustion interaction is based on a combination of finite rate/eddy dissipation model applied to a reduced chemical mechanism with four reactions. Next, the paper refers to the derivation of a Reduced Order Model (ROM) for the same problem, based on the Proper Orthogonal Decomposition (POD) technique. ROMs are used to obtain fast and accurate results, needed in the areas of flow control. The flow and thermal fields obtained with ROMs are compared with the ones obtained from the full simulation and an analysis on the number of modes required to achieve the desired accuracy is presented. Finally, a static control technique is proposed.