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)

1 Throttle valve

2 AFM

3 Engine Control Unit(ECU)

4 Filter 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 detailsInvestigation 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 workNumerical 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)AI inlet of the AFMAO outlet 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:Gradient Least squares cell basedPressure Standard (due to porous zone)Momentum Second order upwindingTurbulent kinetic energy Second order upwindingSpecific dissipation rate Second 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 - lowerY 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