Gasoline Spray (Spray G) Topic 3.5 Internal flow modeling Ron Grover (GM)

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

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

Spray G – Model Setup • Fluid Solver HRMFoam (c/o UMass) • Turbulence k-epsilon • Assumptions Submerged Fluid, Incompressible, Isenthalpic • Meshing 414,000 cells • Mesh Topology Polyhedral (STAR-CCM+) 2 layer extrusion on wall • Needle Motion 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

Spray G – Run to Steady State Predicted CD ~ 0.50 Cv ~ 0.73 CA~ 0.69 GM Measurement CD~ 0.52

Spray G – Internal Flow Results

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

Discharge Coefficient Per Hole 2 3 1 8 4 5 7 6 Time=2.8ms

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

Thank-You

Gasoline Spray (Spray G) Topic 3.5 Internal flow modeling Ron Grover (GM)

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