The priority of the environmental politics and the responsibility to control and reduce the environmental degradation led to a technological evolution in the direction of avoiding at, minimizing the pollution without modifying the industrial processes, while an international crisis linked to oil price increase determined the pursuit of renewable energy sources, independent from fossil ones In the context of using alternative fuels for gas turbines, the paper studies, based on numerical experiments, the constructive solution for transforming an aviation gas turbine into an aero-derivative one, working on gaseous fuel. The first part is dedicated to a comparative examination of several representative fuels, analyzed from the point of view of their combustion performances in an aviation gas turbine. The characteristics of using various gaseous fuels are presented comparatively, each variant being described with advantages and disadvantages. The burning process in the modified combustion chamber is simulated using a commercial CFD code. The main goal of the CFD applications is to define, for steady states, the optimum fuel injector geometrical configuration in order to transform the combustor chamber for gas fuel such as the new gas turbine works in safety conditions - a stabilized process and the expected flow and wall temperatures. The geometry is optimized to obtain a stabile flame that doesn't burn the combustion chamber walls and the first stator stage of the turbine. The conclusions are related to previous successful experiments on the test bench, realized following the natural gas combustion numerical simulations.
