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Towards ECN 4 Topic 7: Spray B in engines Guidelines. Louis-Marie MALBEC – IFPEN/Sandia September 4th 2014. CONTEXT. ECN until now Experiment: similar facilities + large optical accesses => consistent and “exhaustive” database, boundary conditions well controlled Modelling:
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Towards ECN 4 • Topic 7: Spray B in engines • Guidelines Louis-Marie MALBEC – IFPEN/Sandia September 4th 2014
CONTEXT ECN until now • Experiment: • similar facilities + large optical accesses => consistent and “exhaustive” database, boundary conditions well controlled • Modelling: • only one facility to model + steady-state conditions => several parametric variations are possible • Validation/comparison of the models • Bring more detailed analysis of experimental data
CONTEXT ECN in engines • Experiment: • different facilities + small optical accesses => one dataset per engine, lots of information are not accessible, low details on boundary conditions • Modelling: • Several facilities to model + transient behaviour => requires more time • Validation is not possible. ≠ Engine 1 Engine 2 Unknown Boundary Conditions Database 1 Database 2 Validation Validation Model 1 => Need to define new objectives for Spray B in engines
OBJECTIVES Identify and understand the differences between the spray B in combustion vessels (no initial velocities, no wall interactions, constant temperature and density…) and in engines. ≠ Engine 1 Engine 2 Unknown Boundary Conditions Database 1 Database 2 Models Vessels Database
OBJECTIVES Identify and understand the differences between the spray B in combustion vessels (no initial velocities, no wall interactions, constant temperature and density…) and in engines. Experiment: Identifying differences between Spray B in vessels and in engines Modelling: Bring more in depth analysis, in order to understand the causes of these differences.
METHODOLOGY • Reproducing with models experimental databases: are the same differences obtained? • 1) Modelling spray B in vessels • 2) Modelling Spray B in engine 1 • 3) Modelling Spray B in engine 2 • Imposed boundary conditions for each engine (flow field, wall temperature…), at BDC. Multiplication of the geometries Imposed Boundary Conditions for engine 2 Imposed Boundary Conditions for engine 1
BOUNDARY CONDITIONS • Ambient • Must be targeted at TDC • 2 temperatures: 900K and 800K • 3 geometries x 2 operating points = 6 cases for modellers • Injection • Short injection duration (1.5ms effective) • Prail = 1500b • Triggered so that ignition starts near TDC
EXPECTED DATA Experiments: • Liquid length • Mie scattering. DBI if possibility (additionnal) • Vapour penetration • Schlieren • Ignition delay • Pressure based • Lift-off length • OH* chemiluminescence • Ignition sites location • Broadband luminosity (high speed) Modelling: • Same as above • Thermal boundary layer • Velocity fields • Temperature • Mixture fraction fields • Interesting species (OH, formaldehyde…) • …
CONTRIBUTIONS Experiments: • SANDIA (large bore engine) • IstitutoMotori (small bore engine) • Lund/TUE/Imperial College ? • KAIST ? • Wayne State University ? Modelling: • Carnegie Mellon (yes) • Poli. Milano (yes) • Engine flows? • other Spray A contributors?