Ricerc@Sapienza

The present article deals with the design of a micro turbogas turbine suitable for on board applications, e.g., as a power generator on hybrid transit bus, characterized by a simple constructive approach. Deriving the machine layout from an existing KJ-66 aircraft model engine, the authors propose a theoretical design of a compact, lightweight turbogas turbine, by investigating the technical possibility and limits of the proposed design.

An analysis of the erosion due to water droplet on a compressor blade is performed. The study reports the erosion patterns due to droplets of 15 μm diameter dragged by the main flow. An analysis of the droplets dynamics and erosion patterns is provided. The study put in evidence the influence of the tip leakage vortex and the separation close to the hub on the droplet motion and erosion patterns.

An analysis of the erosion due to water droplet on a compressor blades case is performed. The study reports the erosion patterns due to droplets of 15 μm diameter dragged by the main flow. An analysis of the droplets dynamics and erosion patterns is provided. The study put in evidence the influence of the tip leakage vortex and the separation close to the hub on the droplet motion and erosion patterns.

Blade fouling is a very relevant problem in turbomachin-ery applications. It affects both compressors and turbines. In the first case, fouling can be generated by the presence of dust, ashes or brackish air (in offshore applications). In turbines, fouling is mainly generated by residual of combustion process. Blade fouling generally leads to a reduction of the performance due to an increase on profile losses. Here we focus on the foul-ing due to salt deposition on naval/off-shore applications refer-ring to machines that are part of the fleet of gas turbines man-ufacturers.

Here, a new model for predicting the water droplet erosion (WDE) from online water washing in compressors is developed and its results are discussed in comparisons with a baseline model. The model development started with the analysis of existing WDE models as well as pertinent experimental campaigns aiming at extracting a comprehensive erosion model able to account for the influence of droplet velocity and diameter, impact angle, surface roughness and hardness on the erosion phenomena.

Recent year witnessed an increasing interest in online water washing technique since it allows to minimize compressor performance losses in the time interval between two off line washing. However, the washing capability and the related erosion risk depend on several parameters such as the injection duration , the d roplet size , the s pray angle , the water mass flow rate and the i nje ctor position s The influence of such parameters on the washing capability and erosion rate is analysed .