ECN Spray G Internal Flow Modeling Gasoline Spray

ECN Overview Research Questions • Can we actually get results? • What is a

ECN Spray G – Model Setup • Fluid Solver • Turbulence • Assumptions •

ECN Spray G – Run to Steady State Predicted CD ~ 0. 50 Cv

ECN Spray G – Velocity Cut Planes Nozzle Hole Exit Counterbore Exit Time=2. 8

ECN Discharge Coefficient Per Hole % Flow CD Deviation (%) 1 12. 0 0.

ECN Summary & Discussion Points Initial Findings • CFD calculations show that deficit in

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ECN Spray G – Internal Flow Modeling Gasoline Spray (Spray G) Topic 3. 5 Internal flow modeling Ron Grover (GM) 1

ECN Overview Research Questions • Can we actually get results? • What is a representative discharge coefficient injector? • What is the flow field exiting the injector? • What is the deviation in mass flow per hole? Outline • Model setup and assumptions • Mass flow calculations • Nozzle exit velocity field • Summary and discussion 2

ECN Spray G – Model Setup • Fluid Solver • Turbulence • Assumptions • Meshing • Mesh Topology • Needle Motion HRMFoam (c/o UMass) k-epsilon Submerged Fluid, Incompressible, Isenthalpic 414, 000 cells Polyhedral (STAR-CCM+) 2 layer extrusion on wall None. Fixed maximum lift 45 µm Nozzle cell size ~ 20 -30 µm L/D ~ 1 (nozzle) L/D ~ 1. 2 (c-bore) Cell size ~ 30 – 65 µm 3

ECN Spray G – Run to Steady State Predicted CD ~ 0. 50 Cv ~ 0. 73 CA ~ 0. 69 GM Measurement CD ~ 0. 52 4

ECN Spray G – Internal Flow Results 5

ECN Spray G – Velocity Cut Planes Nozzle Hole Exit Counterbore Exit Time=2. 8 ms 6

ECN Discharge Coefficient Per Hole % Flow CD Deviation (%) 1 12. 0 0. 50 -3. 65 2 12. 2 0. 50 -2. 10 3 12. 5 0. 52 0. 34 4 14. 1 0. 58 13. 01 5 11. 4 0. 47 -8. 96 6 11. 5 0. 47 -8. 30 7 14. 5 0. 60 16. 10 8 11. 7 0. 48 -6. 44 3 2 1 8 4 5 7 6 Time=2. 8 ms 7

ECN Summary & Discussion Points Initial Findings • CFD calculations show that deficit in discharge coefficient is equally attributed to both a velocity and area deficit • The velocity distribution per hole is biased towards the side of the hole closest to the injector axis • An instantaneous snapshot of discharge coefficient per hole shows variation; a finding that requires further investigation Call for Additional Contributions! • Solicit various modeling approaches (1 -fluid, 2 -component, etc. ) • Increased mesh resolution • Effect of plenum size • Needle motion effects • Internal-to-external nozzle flow coupling 9

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