Skip to content

[fp024c] Side Mirror Comparison (Passive Flow Jet Control)

Jump to bottom Edit New page
Yosuke Yamamoto edited this page Sep 24, 2018 · 112 revisions

fp024c - Side Mirror Comparison (Passive Flow Jet Control)

Introduction

Ferrari introduced very interesting side mirrors for their 2018 F1 car. Toro Rosso and Red Bull followed it.

The design of the side mirror seems to use a passive flow jet control.

In this study, a passive flow jet mirror and closed fairing mirrors ware simulated and compared to know their characteristics.

Models

Model Car Overview

fp-024c_cfd-model_overview

Side Mirror Models

fp-024c_cfd-model_side-mirrors


Side Mirrorless

  • No Mirror









Side Mirror Origin

  • Closed Fairing









Side Mirror B

  • Passive Flow Jet
  • Shape along Flow of "Side Mirrorless"
  • Road Legal
    • Legal Size of Mirror Surface
    • No edge with radius less than 2.5[mm]




Side Mirror C

  • Closed Fairing
  • Shape of Side Mirror B extended forward
  • Shape along Flow of "Side Mirrorless"
  • Road Legal
    • Legal Size of Mirror Surface
    • No edge with radius less than 2.5[mm]




Simulations

SimScale Project: https://www.simscale.com/workbench/?pid=2112433938440842326#tab_0-0

Conditions

  • Freestream Velocity Magnitude Value : 30 [m/s]
  • Ride Height : Front / Rear = 110 [mm] / 110 [mm]
  • RF : Radiator Flow [m3/s]

Results - Coefficients

Side Mirror-less

Coef. Whole Car Body & Mirror Body Mirror Fr Wheel Rr Wheel
Cd 0.5606 0.4481 0.4481 0.0000 0.0495 0.0629
Cl -0.1979 -0.2359 -0.2359 0.0000 0.0305 0.0074
Clf -0.0761 -0.1202 -0.1202 0.0000 0.0365 0.0077
Clr -0.1218 -0.1156 -0.1156 0.0000 -0.0059 -0.0003
CoP 0.6155 0.4902 0.4902 -0.1943 -0.0355
L/D -0.3531 -0.5263 -0.5263 0.6163 0.1180
RF 0.1616 m3/s

Side Mirror - Origin

Coef. Whole Car Body & Mirror Body Mirror Fr Wheel Rr Wheel
Cd 0.5630 0.4521 0.4442 0.0078 0.0490 0.0619
Cl -0.1759 -0.2126 -0.2273 0.0147 0.0302 0.0065
Clf -0.0546 -0.0983 -0.1103 0.0120 0.0361 0.0076
Clr -0.1213 -0.1143 -0.1170 0.0027 -0.0059 -0.0011
CoP 0.6894 0.5377 0.5147 0.1822 -0.1944 -0.1649
L/D -0.3124 -0.4703 -0.5117 1.8818 0.6164 0.1050
RF 0.1619 m3/s

Side Mirror - B

Coef. Whole Car Body & Mirror Body Mirror Fr Wheel Rr Wheel
Cd 0.5655 0.4534 0.4459 0.0075 0.0494 0.0628
Cl -0.1953 -0.2324 -0.2345 0.0020 0.0303 0.0068
Clf -0.0693 -0.1132 -0.1166 0.0035 0.0362 0.0077
Clr -0.1260 -0.1192 -0.1178 -0.0014 -0.0059 -0.0009
CoP 0.6453 0.5131 0.5025 -0.6959 -0.1951 -0.1247
L/D -0.3453 -0.5126 -0.5258 0.2725 0.6139 0.1087
RF 0.1620 m3/s

Side Mirror - C

Coef. Whole Car Body & Mirror Body Mirror Fr Wheel Rr Wheel
Cd 0.5653 0.4534 0.4448 0.0085 0.0492 0.0628
Cl -0.1942 -0.2314 -0.2326 0.0012 0.0301 0.0071
Clf -0.0680 -0.1117 -0.1150 0.0032 0.0360 0.0077
Clr -0.1261 -0.1197 -0.1177 -0.0020 -0.0059 -0.0006
CoP 0.6496 0.5171 0.5058 -1.6393 -0.1956 -0.0783
L/D -0.3435 -0.5104 -0.5230 0.1429 0.6127 0.1133
RF 0.1622 m3/s

Comparisons

Coefficients and Radiator Flow Comparison

Coef. Mirrorless Side Mirror Origin Side Mirror B Side Mirror C
Cd 0.5606 0.5630 0.5655 0.5653
Cl -0.1979 -0.1759 -0.1953 -0.1942
Clf -0.0761 -0.0546 -0.0693 -0.0680
Clr -0.1218 -0.1213 -0.1260 -0.1261
CoP 0.6155 0.6894 0.6453 0.6496
L/D -0.3531 -0.3124 -0.3453 -0.3435
RF 0.1616 0.1619 0.1620 0.1622

Differences from Mirrorless

Coef. Mirrorless Side Mirror Origin Side Mirror B Side Mirror C
Cd 0.0000 0.0024 0.0050 0.0047
Cl 0.0000 0.0220 0.0026 0.0037
Clf 0.0000 0.0215 0.0068 0.0081
Clr 0.0000 0.0005 -0.0042 -0.0043
CoP 0.0000 0.0739 0.0298 0.0341
L/D 0.0000 0.0406 0.0078 0.0096
RF 0.0000 0.0003 0.0004 0.0006

fp024c_cfd_coef-comparison

  • Remarkable front downforce decrease (lift increase) of "Side Mirror Origin"

Cd Comparison

Mirror Type Whole Car Body Mirror Fr Wheel Rr Wheel
Mirrorless 0.5606 0.4481 0.0000 0.0495 0.0629
Side Mirror Origin 0.5630 0.4442 0.0078 0.0490 0.0619
Side Mirror B 0.5655 0.4459 0.0075 0.0494 0.0628
Side Mirror C 0.5653 0.4448 0.0085 0.0492 0.0628

Differences from Mirrorless

Mirror Type Whole Car Body Mirror Fr Wheel Rr Wheel
Mirrorless 0.0000 0.0000 0.0000 0.0000 0.0000
Side Mirror Origin 0.0024 -0.0039 0.0078 -0.0005 -0.0010
Side Mirror B 0.0050 -0.0023 0.0075 -0.0002 -0.0001
Side Mirror C 0.0047 -0.0033 0.0085 -0.0003 -0.0002

fp024c_cfd_cd-comparison

  • The drags of only the mirrors are almost similar.
    • Although the differences are small, "Side Mirror B" has the smallest drag.
  • The differences of the body drag reductions by the mirrors are larger than the differences of the drags of the only mirrors.
    • "Side Mirror Origin" has the largest reduction in body drag.

Cl Comparison

Mirror Type Whole Car Body Mirror Fr Wheel Rr Wheel
Mirrorless -0.1979 -0.2359 0.0000 0.0305 0.0074
Side Mirror Origin -0.1759 -0.2273 0.0147 0.0302 0.0065
Side Mirror B -0.1953 -0.2345 0.0020 0.0303 0.0068
Side Mirror C -0.1942 -0.2326 0.0012 0.0301 0.0071

Differences from Mirrorless

Mirror Type Whole Car Body Mirror Fr Wheel Rr Wheel
Mirrorless 0.0000 0.0000 0.0000 0.0000 0.0000
Side Mirror Origin 0.0220 0.0085 0.0147 -0.0003 -0.0009
Side Mirror B 0.0026 0.0014 0.0020 -0.0002 -0.0006
Side Mirror C 0.0037 0.0032 0.0012 -0.0004 -0.0003

fp024c_cfd_cl-comparison

  • Side Mirror B and C decrease the amount of downforce reduction compared with Side Mirror Origin.
    • The shape of the mirror along the flow seems important for the downforce.

Streamline Comparison

Streamlines around the mirrors (GIF Animation)

fp024c_cfd_side-mirrors_ym650-streamlines

Side Mirrorless

  • Around 15-20 [deg] upward flow in the area for side mirrors






Side Mirror Origin

  • The flow above the mirror is bent downward.
    • This seems one cause of lift force generation.




Side Mirror B

  • The changes in flow seem smallest and smooth.







Side Mirror C

  • The flow resembles that of "side mirror B".
  • Some of the flow passing below the mirror is bent upward.





Comparison of Side Mirrors B and C - Detailed Streamlines

fp024c_cfd_streamlines_side-mirror-b-c_ym650_zoomin-more_b

Side Mirror B

  • Jet flows are generated between the outer and inner fairings.
  • The upper jet flow seems not enough.






Side Mirror C

  • The confluence point seems closer to the mirror than Side Mirror B.







Summary

  • Drags
    • Compared with only the mirrors, the drag of the Side Mirror B using "Passive Flow Jet Control" aimed at reducing drag is the smallest. However, the differences are small.
    • The differences of the body drags due to the mirrors are larger than the differences of the drags of the mirrors only.
    • It is necessary to evaluate the drag on the whole car.
  • Downforce
    • Side Mirror Origin decreases the front downforce remarkably.
    • Side Mirror B and C decrease the amount of downforce reduction compared with Side Mirror Origin.
    • The shape of the mirror along the flow seems important for the downforce.
Add a custom footer
Add a custom sidebar

Clone this wiki locally