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Proposing Institution

Lehrstuhl für Aerodynamik, TU München
Project Manager

Dr.-Ing. Steffen Schmidt
Boltzmannstr. 15
85748 Garching
This project focuses on numerical analysis of the dynamics ofcavitating flows within injection systems and micro valves of modernautomotive engines, as well as of the flow around pump- and turbineblades and ship propellers. All simulations will be performed withour validated in-house CFD code CATUM which relies on a 3-D highresolution finite volume scheme together with a modified Godunovflux. CATUM enables high quality predictions of complex flow phenomenaincluding unsteady shock formation and wave propagation due tocollapsing vapor clouds within compressible two-phase flows of low andhigh Mach numbers. In the first phase of the project we willinvestigate the quality and the numerical performance of recentlydeveloped thermodynamic models of Diesel, gasoline and water includingphase transition. The available data of experimental investigationswill be used to validate our numerical predictions. The second goalduring the first phase is to further develop our existing module topredict cavitation erosion which is highly relevant for industrialapplications. The existing module to predict erosion is based onanalyzing the shock induced maximum pressure that occurs during thewhole simulation within each cell of the computational domain. Thisapproach provides ad hoc predictions of those areas where erosion ismost likely to occur, but no rate of material removal can beestimated. The new approach will be based on a significantly moredetailed analysis of the arising maximum loads by analyzing theirimpulsive strength as well as their frequentness and their localdistributions. This approach will allow us to estimate the rates ofmaterial removal due to collapse induced cavitation erosion. Afterevaluating these new models against experimental data within systemsof reduced geometrical complexity we will investigate the flow withinmodern injection nozzles of automotive engines. The results of thesesimulations will provide detailed insight even into those flowphenomena that cannot be analyzed experimentally. Especially, theprediction of the erosiveness will provide crucial new informationthat will lead to improvements of the design of modern high pressureinjectors and to enlarge the life time of turbines and pumps.

Impressum, Conny Wendler