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This paper analyzes the performances and the emissions of the JETCAT P80 microengine, when jet A jet A +  10% biodiesel (BD), jet A + 20% biodiesel, and jet A + 30% biodiesel are utilized as fuel, and to each of these combinations is added 5% of Aeroshell Oil 500. The performances will be assessed based on the engine speed, for the generated thrust force, the temperature in front of the turbine, and on the fuel flow. The paper will investigate the performances and the emissions generated by the four fuel blends burning when the engine is idle, at the cruise and at the max regime. This will be realized by maintaining each of these regimes for approximately a minute and a half. During the tests, the vibrations were monitored both radially and axially for the observation of the engine function regimes. From the measurements, the concentrations of SO2, NOx, and CH4 will be analyzed, highlighting the emissions of SO2. There were performed measurements to determine the fuel blend's density in order to transform the values of the fuel flow from liter per hour into kilogram per second. Having these data registered from the engine, a jet engine cycle analysis at max regime will be performed based on the combustion efficiency, the thermal efficiency of the engine, and the specific fuel consumption.

Numerical simulations of flames unstable, due to a parametric acoustic forcing, are performed in this paper. Results concerning the threshold of this instability are compared to quasi-steady theoretical predictions. Important disagreements are found at large frequencies. suggesting that the Markstein lengths relative to curvature and stretch are frequency dependent. Results are discussed in connection to experiments and to new theoretical ideas.

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