1 Gasoline Spray (Spray G) Topic 3.5Internal flow modeling Topic 3.5 Internal flow modeling Ron Grover (GM) Spray G – Internal Flow Modeling

2 Outline Model setup and assumptions Mass flow calculations Nozzle exit velocity field Summary and discussion 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?

3 Fluid SolverHRMFoam (c/o UMass) Turbulencek-epsilon AssumptionsSubmerged Fluid, Incompressible, Isenthalpic Meshing414,000 cells Mesh TopologyPolyhedral (STAR-CCM+) 2 layer extrusion on wall Needle MotionNone. Fixed maximum lift 45 µm Cell size ~ 30 – 65 µm Nozzle cell size ~ µm Spray G – Model Setup L/D ~ 1 (nozzle) L/D ~ 1.2 (c-bore)

4 Predicted C D ~ 0.50 C v ~ 0.73 C A ~ 0.69 Spray G – Run to Steady State GM Measurement C D ~ 0.52

5 Spray G – Internal Flow Results

6 Counterbore Exit Time=2.8ms Nozzle Hole Exit Spray G – Velocity Cut Planes

7 Hole% FlowCDDeviation (%) Time=2.8ms Discharge Coefficient Per Hole

8 Hole % Flow CD Deviation (%) Discharge Coefficient Per Hole Time=2.8ms

9 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 Summary & Discussion Points

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