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