ZURUECK HOCH VOR INHALT SUCHEN

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Proposing Institution

Lehrstuhl für Aerodynamik, TU München
Project Manager

Dr.-Ing. Steffen Schmidt
Boltzmannstraße 15
85748 Garching
Abstract
Cavitation denotes the phenomenon of evaporation of a liquid medium and the subsequent formation of vapor cavities due to a local drop of pressure below the vapor pressure of the considered liquid. When vapor cavities are advected in regions where the pressure of the surrounding liquid is above the vapor pressure, sudden recondensation occurs accompanied by a high acceleration of the surrounding liquid and the formation of strong shock waves. The vigorous collapse of vapor cavities can lead to damage of material (cavitation erosion) or even failure of the device.Flow configurations subject to cavitation are found, e.g., in hydraulic valves of fuel injection systems. Modern diesel injection systems aim at higher and higher injection pressures (2000 bar and above) in order to minimize emissions and to maximize fuel efficiency. Higher injection pressures generally lead to larger pressure differences across valves making them more prone to cavitation. Consequently, the engineer needs to be able to accurately predict and control cavitation during the design process of modern diesel injection systems in order to minimize the risk of a failure during the life cycle of the injector.Among the many open questions related to this topic are the influence of turbulence on cavitation and vice versa as well as the influence of condensable inert gas solved in the liquid. Detailed experimental insight is limited since typical flow geometries are in the order of 10-3 m and below. This makes high fidelity numerical simulations an ideal tool in answering these questions.

Impressum, Conny Wendler