Numerical investigation on the upstream flow condition of the air flow meter in the air intake assembly of a passenger car Zoltán Kórik Supervisor: Dr. Jenő Miklós Suda by

Introduction In a fuel injection system the main goal is to have the desired fuel-air mixture (max power with min consumption and emission) We must know the accurate mass flow rate of air measured by the Air Flow Meter (AFM) 1Throttle valve 2AFM 3Engine Control Unit (ECU) 4Filter housing Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik

The investigated assembly in the car Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik

Assembly details Investigation of the influence of the upstream conditions (with funnel and without funnel) Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik

Measurement Measurement data were provided by a BSc Thesis work Numerical model based on the experimental setup: - Inlet and outlet geometry - Boundary conditions - Filter model Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik

Geometry modelling Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik

Cases Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik H M L β α

Pressure taps Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik 4 static pressure tap at each cross section: FB “bottom” of the filter (upstream) FT “top” of the filter (downstream) AIinlet of the AFM AOoutlet of the AFM

Plot planes Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik x z z y z Well defined main flow direction through the AFM

Mesh Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik Different volume zones (mesh control and porous zone) Target number of cells: 2 million Method: Octree

Numerical settings Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik Pressure based solver with absolute velocity formulation Steady “initialization” (1000 iteration) Transient simulation (200 step with 0.01s time step, 50 iterations/step) Viscous model: k-ω – SST Pressure velocity coupling: SIMPLE Spatial discretizations: GradientLeast squares cell based PressureStandard (due to porous zone) MomentumSecond order upwinding Turbulent kinetic energySecond order upwinding Specific dissipation rateSecond order upwinding Constant density

Boundary conditions and evaluation Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik Inlet:Mass flow rate prescribed on the half-sphere based on measurement data Outlet:Outflow Evaluation Calculation of loss coefficients: Cumulative average of the static pressure values Visualization: Flow field of the last time step H1 AO average

Filter modelling Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik Handled as porous zone Coefficients in through flow direction were calculated based on measurement data Non-homogeneous  other directions can be estimated only Local coordinate system

Coefficient iteration and directional dependence Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik X direction - lower Y direction - higher H1 case was used

Resulting flow field in the filter zone Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik H0 case (sectional streamlines)

Contour plots Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik High loss when the funnel is not present, due to contraction.

Contour plots Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik Zero z velocity component iso-surface

Contour plots Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik Velocity magnitude

Contour plots Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik Static pressure with sectional streamlines

Contour plots Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik Different secondary flow at the inlet

Contraction loss coefficient Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik Significant difference can be shown.

Pressure distribution - taps Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik

Pressure drop Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik Good agreement at FT and AI The difference at AO is probably due to a loosen tap

Animations Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik Z velocity Iso-surface sweep (pressure contours) Z coordinate sweep (velocity contours)

Conclusion Introduction Geometry modelling Mesh Numerical setting and boundary conditions Filter modelling Results Conclusion MSc Thesis presentation Zoltán Kórik The influence of the funnel could be shown with developed model. It has potential for further development. Transient operation can be interesting!

Thank you for your attention! Q & A