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- Pressure Based Comparison of Different Gas Turbine Ground Vortex FlowsPublication . Barata, Jorge M M; Manquinho, Pedro; Silva, AndréThe present paper has the previous work of Barata et al in mind and has the purpose of analyzing the behavior of ground vortex flows through several values of height of the engine axis above the ground, diameter of engine intake and inlet airflow velocity using pressure on the ground and in a 3D scale for that.
- A comparison of different gas turbine engines ground vortex flowsPublication . Manquinho, Pedro Alexandre Rodrigues; Barata, Jorge Manuel Martins; Silva, André Resende Rodrigues daThe design of an engine intake is very important because, it is one of the engine components that directly interface with the flow around the engine and the internal airflow. The inlet is designed to give the appropriate amount of airflow required from the free-stream conditions to the conditions required at the entrance of the compressor with minimal pressure loss by the engine1. When the pressure losses and the flow distortions are very low, the performance of the engine is optimal, and that is the reason why the airflow has to be as uniform as possible when entering into the compressor. This airflow condition is necessary in all flight configurations including when the aircraft is maneuvering on ground tasks. The intake performance depends on the mass-flow delivered to the compressor. [...]
- A Comparison of Different Gas Turbine Engines Ground Vortex FlowsPublication . Barata, Jorge M M; Manquinho, Pedro; Silva, AndréA computational method was used to predict and compare the ground vortices forming between the ground and a 1/1th scale model intake of different gas turbine engines. Calculations have been performed for the case of an irrotational crossflow mode of formation. Two different kinds of vortices appear around the intake: an inlet vortex and a trailing vortex. Away from the inlet plane other types of complex vortical structures were also identified. The computational method was found to describe all the main features of the flow for full scale geometry.
- Identification of Gas Turbine Ground Vortex Formation RegimesPublication . Barata, Jorge M M; Manquinho, Pedro; Silva, AndréIn the present paper the preliminary work of Barata et al.11 on gas turbine ground vortex formation is extended to include eighteen different engines that are presently in service. The ground vortex flows produced by each engine are compared and discussed for the corresponding operational condition. The results have shown that more than one mode can occur for a particular engine-velocity ratio-clearance distance combination with 1, 2 or 3 vortexes that may merge before entering the inlet engine. Further improvement of gas turbine design is then required to prevent hazardous operation of aircrafts in the airports.
- Identification of Gas Turbine Ground Vortex Formation RegimesPublication . Barata, Jorge M M; Manquinho, Pedro; Silva, AndréIn the present paper the previous work of Barata et al.11 is extended to include eighteen engines that are being used in the present. The ground vortex flows produced by the different engines are compared and discussed for each operational condition. The results have shown that more than one mode can occur for a particular engine-velocity ratio-clearance distance combination with 1, 2 or 3 vortexes that may merge before entering the inlet engine.
- Gas turbine engines ground vortex flowsPublication . Manquinho, Pedro Alexandre Rodrigues; Barata, Jorge Manuel MartinsWhen an aero-engine is operating near the ground at low aircraft speeds, high thrust and exposed to a crosswind the formation of a potent inlet ground vortex can arise. This structure create significant pressures losses and flow distortions and is swallowed by the engine. As a consequence, fan efficiency and thrust are severely affected and compressor surge may also occur. Inlet ground vortices are the cause of major foreign object damage (FOD) due to the ingestion of rocks, sand and other debris. The ingestion of foreign objects can cause notable damage to engine components as well as overall performance degradation. In the present work the flow fields for a full-scale aero-engine have been simulated for a range of ground clearances, engine diameters and intake velocity ratios under crosswind conditions. The aim of this study is to better understand the ground vortex inlet mechanisms supplying new information to foster vortex avoidance techniques. This work has shown large low pressure regions in front of the engine face for different engine-velocity/ratio-clearance distance combinations that extend to the ground especially where the vortex coalesces. There are two areas of no vortex as a function of h/Di and𝑈𝑖/𝑈∞ . The first is the anticipated frontier (threshold) between the regions vortex/no vortex, but a second one was detected for high values of 𝑈𝑖/𝑈∞ (𝑈𝑖/𝑈∞ >50.00) that had not been mentioned in previous works. The inlet ground vortex mechanism is a very complex one which should be further investigated, and experimental works are desirable.