The atomization and burning of biofuels in the combustion chambers of gas turbine engines

The present work analyzes the effect of physical properties of liquid fuels with high viscosity (including biofuels) on the spray and burning characteristics. The study showed that the spray characteristics behind devices well atomized fuel oil, may significantly deteriorate when using biofuels, until the collapse of the fuel bubble. To avoid this phenomenon it is necessary to carry out the calculation of the fuel film form when designing the nozzles. As a result of this calculation boundary curves in the coordinates of the Reynolds number on fuel - the Laplace number are built, characterizing the transition from sheet breakup to spraying. It is shown that these curves are described by a power function with the same exponent for nozzles of various designs. The swirl of air surrounding the nozzle in the same direction, as the swirl of fuel film, can significantly improve the performance of atomization of highly viscous fuel. Moreover the value of the tangential air velocity has the determining influence on the film shape. For carrying out of hot tests in aviation combustor some embodiments of liquid fuels were proved and the most preferred one was chosen. Fire tests of combustion chamber compartment at conventional fuel has shown comprehensible characteristics, in particular wide side-altars of the stable combustion. The blended biofuel application makes worse combustion stability in comparison with kerosene. A number of measures was recommended to modernize the conventional combustors when using biofuels in gas turbine engines. (paper)