W ATER : V OLVO C ARS , FFI PROJECT , 2006-2011 U Water inlet L. - - PowerPoint PPT Presentation

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W ATER : V OLVO C ARS , FFI PROJECT , 2006-2011 U Water inlet L. - - PowerPoint PPT Presentation

Nov 26, 2022 175 likes •509 views

H OW TO CARRY OUT FUNDAMENTAL RESEARCH TOGETHER WITH INDUSTRY Lars Davidson Division of Fluid Dynamics Dept. of Mechanics and Maritime Sciences (M2) Chalmers A PPLIED AND F UNDAMENTAL R ESEARCH I will show five nice examples of fundamental

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SLIDE 1

HOW TO CARRY OUT FUNDAMENTAL RESEARCH

TOGETHER WITH INDUSTRY

Lars Davidson Division of Fluid Dynamics

  • Dept. of Mechanics and Maritime Sciences (M2)

Chalmers

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SLIDE 2

APPLIED AND FUNDAMENTAL RESEARCH

I will show five nice examples of fundamental research carried out together with industry

◮ Water droplets/ruvulets on side mirrors ◮ Heat transfer in engines: exp & simulation ◮ External windnoise disturbing driver and passengers (automotive) ◮ Using active flow control for reducing drag on vehicles ◮ Heat transfer in engines: development of simulation method

  • L. Davidson, FFI, April 2019

Applied and Fundamental 2 / 25

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SLIDE 3

WATER: VOLVO CARS, FFI PROJECT, 2006-2011

Water inlet U∞

  • L. Davidson, FFI, April 2019

Applied and Fundamental 3 / 25

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SLIDE 4

WATER: EXPERIMENT

(A) Scatter plot. Air velocity Vair = 13 (B) Different air velocities.

FIGURE: Velocity of waterdrops that left the table.

ρℓhcVair σ = −155 + 280Vair

  • T. Tivert and L. Davidson Experimental study of water transport on a generic mirror, International

Conference on Multiphase Flow,ICMF, Tampa, FL, US, 2010.

  • L. Davidson, FFI, April 2019

Applied and Fundamental 4 / 25

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SLIDE 5

ENGINES: VOLVO CARS, FFI PROJECT, 2009-2014

Real engine Simplified case Piston top simplified as a series of horizontal and inclined plans Impinging jet flow and heat transfer

  • L. Davidson, FFI, April 2019

Applied and Fundamental 5 / 25

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SLIDE 6

ENGINES: EXP & SIMULATIONS

(A) Setup (B) Computational domain

FIGURE: Simplified setup

  • M. Bovo and L. Davidson “Direct comparison of LES and experiment of a single-pulse impinging

jet”, International Journal of Heat and Mass Transfer, Vol. 88, pp. 102-110, 2015.

  • L. Davidson, FFI, April 2019

Applied and Fundamental 6 / 25

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SLIDE 7

ENGINES: RESULTS

(A) Velocities at three instants.

Velocities at three instants Surface temperature wall normal velocity, 0.6ms

  • L. Davidson, FFI, April 2019

Applied and Fundamental 7 / 25

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SLIDE 8

ACOUSTICS, VOLVO & VCC, FFI PROJECT 2014-2018

W inds reen A-pillar Plenum Du k tail Hood Side mirror Side windo w Beltline x y z

side mirror Cavity

  • L. Davidson, FFI, April 2019

Applied and Fundamental 8 / 25

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SLIDE 9

AERO-VIBRO ACOUSTICS: FFI PROJECT 2014-2018

An important source of the interior noise in vehicles is the window vibration that is excited by

◮ the exterior flow (indirect noise generation). ◮ the exterior flow-induced noise (direct noise transfer).

Boundary layer Noise from Vortices Structure Noise due to Noise due to hydrodynamic acoustic Exterior side Interior side vortices pressure pressure Vibration Noise from boundary layer

  • L. Davidson, FFI, April 2019

Applied and Fundamental 9 / 25

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SLIDE 10

APPLICATION 1 – GENERIC SIDE-VIEW MIRROR (1)

The exterior turbulence creates interior noise by making the window glass vibrate

1.4 0.8 0.2 0.2 1.6 1.4 1.2 0.1 1.2 0.1 0.1 0.1 X Y Z Glass window GSV Mirror Rigid plate Cavity

(A) Domain with mirror, glass window and cavity.

Pressure of interior noise Generic side view mirror Glass window Cavity Vortices Pressure on window

(B) CFD, vibrating window, noise propagation in cavity.

H.-D. Yao & L. Davidson, “Generation of interior cavity noise due to window vibration excited by turbulent flows past a generic side-view mirror”, Phys. Fluids, Vol. 30, 036104, 2018

  • L. Davidson, FFI, April 2019

Applied and Fundamental 10 / 25

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SLIDE 11

APPLICATION 1 – GENERIC SIDE-VIEW MIRROR (2)

Compressibility: compressible vs. incompressible. Turbulence modeling: detached eddy simulation vs. large eddy simulation. Acoustics: direct vs. indirect simulation using acoustic perturbation equations. Grid topologies: trimmed vs. polyhedral cells.

X Z (a) (b) 7 6 5 4 3 2 1

Trimmed mesh

X Z (a) (b) X Y

Polyhedral mesh

  • L. Davidson, FFI, April 2019

Applied and Fundamental 11 / 25

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SLIDE 12

APPLICATION 1 – GENERIC SIDE-VIEW MIRROR (3)

The contributions of the exterior hydrodynamic and acoustic pressure fluctuations to the interior noise generation are addressed.

0.05 0.12 0.19 0.26 0.33 0.4 C-LES I-DES with polyhedral mesh I-DES with trimmed mesh C-DES 0.3 0.6 0.9 1.2 0.3 0.6 0.9 1.2 x x 0.6 0.3

  • 0.3
  • 0.6

0.6 0.3

  • 0.3
  • 0.6

z z

(A) RMS values of surface pressure fluctuations

(a) (b)

(B) SPLs of interior noise at Mic. 4 (bottom corner)

  • L. Davidson, FFI, April 2019

Applied and Fundamental 12 / 25

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SLIDE 13

APPLICATION 2 – FULL-SCALE TRUCK (1)

The installation effect of a side-view mirror is studied. The simplification strategy for a full-scale production truck is validated.

(a) (b)

Original and simplified trucks

X Z Y X Y Z Window Upper mirror head Bottom mirror head Mirror bracket Window Upper mirror head Bottom mirror head Mirror bracket A-pillar

Side-view mirror components, the A-pillar and the window

H.-D. Yao & L. Davidson, “Simplifications Applied for Simulation of Turbulence Induced by a Side View Mirror of a Full-Scale Truck Using DES”, SAE 2018-01-0708, 2018. H.-D. Yao, L. Davidson, Z. Chroneer, “Investigation of interior noise from generic side-view mirror using incompressible and compressible solvers of DES and LES”, SAE 2018-01-0735, 2018.

  • L. Davidson, FFI, April 2019

Applied and Fundamental 13 / 25

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SLIDE 14

APPLICATION 2 – FULL-SCALE TRUCK (2)

A hybrid mesh of trimmed and polyhedral cells is employed. The mesh is sufficiently refined near the mirror and A-pillar to resolve turbulent flow structures.

X Y Z (a) (b) X Y Z

A hybrid mesh of trimmed & polyhedral cells

X Z 100

  • 120
  • 340
  • 560
✲ ✁ ✂ ✲✄ ✂ ✂ ✂

(Pa) X Y

Snapshots of Q-criterion

  • L. Davidson, FFI, April 2019

Applied and Fundamental 14 / 25

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SLIDE 15

AERODYNAMICS: AB VOLVO, FFI PROJECT 2013-2018

A−pillar

  • L. Davidson, FFI, April 2019

Applied and Fundamental 15 / 25

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SLIDE 16

U

inf

  • L. Davidson, FFI, April 2019

Applied and Fundamental 16 / 25

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SLIDE 17

U

inf

  • L. Davidson, FFI, April 2019

Applied and Fundamental 16 / 25

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SLIDE 18

U

inf

Jet Uinf Membrane Time Jet

  • L. Davidson, FFI, April 2019

Applied and Fundamental 16 / 25

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SLIDE 19

Jet Uinf Membrane Time Jet

D L W S W K A z y

  • L. Davidson, FFI, April 2019

Applied and Fundamental 16 / 25

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SLIDE 20

Uinf Uinf D A C

y/W x/W

x B A B R L

0.5 1 1 1.6

domain y z domain

Laser Camera

Side Rear

AFC

  • L. Davidson, FFI, April 2019

Applied and Fundamental 17 / 25

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SLIDE 21
  • G. Minelli, E. Adi Hartono, V. Chernoray, L. Hjelm and S. Krajnovic “Aerodynamic flow control for

a generic truck cabin using synthetic jets”, Journal of Wind Engineering and Industrial Aerodynamics, Vol. 168, pp. 81-90, 2017.

  • L. Davidson, FFI, April 2019

Applied and Fundamental 18 / 25

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SLIDE 22

AFC OFF AFC ON

  • G. Minelli, S. Krajnovic, B. Basara and B. Noack, “Numerical Investigation of Active Flow Control

Around a Generic Truck A-Pillar”, Flow, Turbulence and Combustion, Vol. 97, pp. 1-20, 2016.

  • L. Davidson, FFI, April 2019

Applied and Fundamental 18 / 25

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SLIDE 23

ENGINES: AB VOLVO, FFI PROJECT ON-GOING

FIGURE: Internal engine combustion of mixture of air and direct injected diesel.

piston valves spray

  • L. Davidson, FFI, April 2019

Applied and Fundamental 19 / 25

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SLIDE 24

IMPINGING JET

FIGURE: Turbulent axisymmetric impinging jet.

  • L. Davidson, FFI, April 2019

Applied and Fundamental 20 / 25

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SLIDE 25

TEST CASE

USED MESH TYPES Mesh for low-Reynolds- number, LRN, modeling Mesh for Numeric Wall Function, NWF Mesh for high-Reynolds- number, HRN, modeling

  • L. Davidson, FFI, April 2019

Applied and Fundamental 21 / 25

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SLIDE 26

WALL FRICTION

FIGURE: Impinging jet at ReD = 220000, comparing; : default LRN, : LRN with NWF mesh, face flux, : wall flux.

  • L. Davidson, FFI, April 2019

Applied and Fundamental 22 / 25

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SLIDE 27

SPEED-UP

1,000 2,000 3,000 Wall flux Face flux LRN w NWF mesh HRN LRN 313 3,470 493 652 624 Steady-state solver time [s] J.-A. B¨ ackar, L. Davidson, “Evaluation of numerical wall functions on the axisymmetric impinging jet using OpenFOAM”, International Journal of Heat and Fluid Flow, Volume 67, pp. 27-42, Part A, 2017.

  • L. Davidson, FFI, April 2019

Applied and Fundamental 23 / 25

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SLIDE 28

AFC AND MACHINE LEARNING

Project leaders: S. Krajnovi´ c and V. Chernoray

  • ✁
✂ ✄ ☎ ✆ ✝ ✞ ✟ ✠ ✡ ☛ ☞ ✌ ✍ ✎ ✏ ✑ ✒ ✓ ✔✕ ✖ ✗ ✘ ✙ ✚ ✛ ✜ ✢ ✣ ✤ ✥ ✦ ✧ ★ ✩ ✪ ✫ ✬ ✭ ✮✯ ✰ ✱ ✲ ✳ ✴ ✵ ✶✷ ✸ ✹ ✺✻ ✼ ✽ ✾✿ ❀ ❁ ❂❃ ❄ ❅ ❆ ❇ ❈ ❉ ❊ ❋
  • ❍
■ ❏ ❑▲
  • ✁
✂ ✄ ☎ ✆ ✝ ✞ ✟ ✠ ✡ ☛ ☞ ✌ ✍ ✎ ✏ ✑ ✒ ✓ ✔✕
  • ✖
✗ ✘ ✙ ✚ ✛ ✜ ✢ ✣ ✤ ✥ ✦ ✧ ★ ✩ ✪ ✫ ✬ ✭ ✮✯ ✰ ✱ ✲ ✳ ✴ ✵ ✶✷ ✸ ✹ ✺✻ ✼ ✽ ✾✿ ❀ ❁ ❂❃ ❄ ❅ ❆ ❇ ❈ ❉ ❊ ❋
  • ❍
■ ❏ ❑▲

Left: A sketch of the flow separation Right: The model placed in the wind tunnel Object: teach the controller to miminize drag by finding optimal A1, A2, f1, f2 in S = A1 sin(2πf1t) + A2 sin(2πf2t) Learning procedure is based on a genetic algorithm (GA)

  • ptimization script
  • L. Davidson, FFI, April 2019

Applied and Fundamental 24 / 25

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SLIDE 29

APPLIED AND FUNDAMENTAL RESEARCH: HOW TO

There is a danger that very applied FFI projects get higher priority than fundamental research

  • L. Davidson, FFI, April 2019

Applied and Fundamental 25 / 25

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SLIDE 30

APPLIED AND FUNDAMENTAL RESEARCH: HOW TO

There is a danger that very applied FFI projects get higher priority than fundamental research How to combine applied & fundamental research?

  • L. Davidson, FFI, April 2019

Applied and Fundamental 25 / 25

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SLIDE 31

APPLIED AND FUNDAMENTAL RESEARCH: HOW TO

There is a danger that very applied FFI projects get higher priority than fundamental research How to combine applied & fundamental research?

◮ Choose the right partner (persons) in industry

  • L. Davidson, FFI, April 2019

Applied and Fundamental 25 / 25

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SLIDE 32

APPLIED AND FUNDAMENTAL RESEARCH: HOW TO

There is a danger that very applied FFI projects get higher priority than fundamental research How to combine applied & fundamental research?

◮ Choose the right partner (persons) in industry ◮ In a project: do both fundamental research (first) and then apply it

(maybe by your industrial partner)

  • L. Davidson, FFI, April 2019

Applied and Fundamental 25 / 25

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SLIDE 33

APPLIED AND FUNDAMENTAL RESEARCH: HOW TO

There is a danger that very applied FFI projects get higher priority than fundamental research How to combine applied & fundamental research?

◮ Choose the right partner (persons) in industry ◮ In a project: do both fundamental research (first) and then apply it

(maybe by your industrial partner)

◮ Go out and visit the industry; make presentations.

  • L. Davidson, FFI, April 2019

Applied and Fundamental 25 / 25