Visualization methods have always been used to inspect flows that are invisible to the naked eye. Seedless velocimetry has been regarded as an alternative to other intrusive quantitative methods and adapted to fit many applications in the industrial or scientific field. Schlieren image velocimetry (SIV) uses the general working principle of a schlieren system to acquire flow images, while relying on a particle image velocimetry (PIV)-like algorithm to obtain quantitative data related to the studied flow. The test case of this study consists of a turbulent round exhaust jet generated by a micro-thruster that uses ${\mathrm{H}}_2-{\mathrm{O}}_2$ as a propellent. Mapping the local velocities of the flow is achieved by initially performing a lagrangian tracking method which makes use of a direct image correlation algorithm. These results are then compared to the velocity map obtained from a kymograph applied to a series of images. The velocity profiles obtained through SIV will be compared to the velocity profile of the jet provided by the CFD simulation. The schlieren investigation of the jet’s local velocity map is set to determine the thruster’s capabilities, and conclude if the thruster reaches the desired Mach for which it has been designed.

The paper presents Particle Image Velocimetry experimental measurements and an ANSYS CFX numerical simulation of the mean and fluctuating velocity field in a turbulent, isothermal flow downstream of a V-shaped bluff body flame stabilizer equipping a post-combustion system installed downstream of a Garrett 30-67 gas turbine engine. The post-combustion system used as experimental model is described in detail, and the main characteristics of the Garrett 30-67 gas generator are included in the paper. Also, the instrumentation used on the experimental rig, including the Particle Image Velocimetry equipment, is briefly described. The presence of a bluff body inside the high speed flow creates a re-circulating wake structure, clearly seen in the experimental data. In the near field, the re-circulating region’s length and width of are captured reasonably well by the numerical simulation, but the momentum rate transfer further downstream is over-predicted, as the grid resolution worsens. An overall over prediction of the axial velocity by the numerical simulation is noted by comparing the numerical simulation results to the experimental data, explained by an over estimated inlet velocity in the numerical simulation, provided by Particle Image Velocimetry experimental measurements in the free exhaust jet behind the gas generator, without the installation of the post-combustion system, thus neglecting the effect of the latter on the operating regime of the gas turbine engine.

The aero-derivative gas turbine represents an advanced solution for technologic transfer from aeronautics to industrial applications, including high efficiency, reduced dimensions and high reliability. The paper, as result of a research project, is focused on an application using an aero-derivative gas turbine as an installation for CO2 rich landfill gas valorization. The paper also presents the potential for landfill gas production in Romania, in the context of the requirements imposed by the environmental laws. A calculation is realized based on demographic statistics, showing the most suitable areas in the country for obtaining the landfill gas. The first part is dedicated to a comparative examination of classical liquid fuel, kerosene, and two gaseous fuels, methane and landfill gas with equal volume ratio of methane and carbon dioxide, analyzed from the point of view of their combustion performances in the gas turbine, with the help of CEA program developed by NASA. Considering the nowadays utilization of CFD simulations for design purpose in many activity fields from the engineering domain, the results provided by the CEA program, along with the ones provided by the gas turbine’s producer, were considered input data for the numerical approaches of the combustion process of methane and landfill gas in the known combustion chamber using a commercial CFD code. The main goal of the CFD applications is to determine the optimum geometric configuration of the new injection system in order to obtain a stabilized process and high performances in safety conditions, for low working regimes and nominal regime, as defined by experimental data and producer’s recommendations. Previous successful experimentations on test bench following the combustion simulation of methane gas and the encouraging results from the CFD simulations lead to new experimentations of the gas turbine working on landfill gas in order to validate the numerical approaches, activity described in the third part of the paper. A technological fueling scheme was designed, the geometrical adjustments were made according to previous simulations and the landfill gas was simulated using a homogenization device installed on the fuel line for a forced mixing of the two non-reactive substances, methane and carbon dioxide. The gas turbine was prepared and instrumented for bench testing and stable working was obtained for speeds of 27–63% of the nominal one. The conclusions are related to the execution of an installation allowing experimentation of gas turbines working on landfill gas and future researches focusing on tests for higher working regimes.

The paper presents two approaches for the thermodynamic cycle analysis applied to gas turbines. For a 1,500 kW industrial engine, still in development, different configurations are considered, the most complex including intercooling and heat recovery components. The theoretical algorithm, a conventional compromise between simplicity and accuracy, is presented in the first part of the paper. The second part describes a numerical approach for calculating the operating cycle of a gas turbine and presenting the methods for preparing the particular required format. The conclusions are related to the future work necessary for finalizing a numerical code able to analyse different gas cycle options allowing to obtain the desired output power and efficiency.