FROM WING CARS TO FLAT BOTTOMS
Jorge Arnedo García – Miguel Andrés Masip – Lucas Bernácer Soriano – Francisco García Villanueva 1. Introduction
- Aerodynamic design of a F1
- Generation of downforce
- Bottom layout
Diffuser and flat bottom layout
Why did they need such a long time to introduce this concept if it was known in the aviation industry since the 20's?
“Aerodynamics are for people who can't build engines”
Enzo Ferrari 1. IntroductionIntroduction
- Aerodynamic design of a F1
- Generation of downforce
- Bottom layout
Diffuser and flat bottom layout
Why did they need such a long time to introduce this concept if it was known in the aviation industry since the 20's?
F1 needed a new generation of engineers
Colin Chapman 2. FundamentalsFundamentals of carsof cars aerodynamics aerodynamics
2.1 Aerodynamical forces Aerodynamical forces
Lateral Downforce Drag stability
- Pulls down the - Resistance force exhorted by the air vehicle to the ground - Looking for reducing this force
- Gives stability when cornering at high speeds 2. Fundamentals of cars aerodynamics
2.1 Aerodynamical forces Aerodynamical forces
Lateral Downforce Drag stability
Monza vs Monaco car configuration 2. FundamentalsFundamentals of carsof cars aerodynamics aerodynamics
2.2 Mechanisms to generate downforce
Lift generation
Downforce generation 2. Fundamentals of cars aerodynamics
2.2 Mechanisms to generate downforce
Downforce generation
Frontal aileron Rear aileron 2. Fundamentals of cars aerodynamics
2.2 Mechanisms to generate downforce
Downforce generation
- Flow acceleration due to the ground effect
- Greater pressure difference
- Suction effect
Bottom layout configuration 2. FundamentalsFundamentals of carsof cars aerodynamics aerodynamics
2.3 Downforce distribution
Downforce generation along the car 3. BottomBottom evolution evolution through through decades decades
3.1 70s: Birth of aerodynamics in F1
Introduction of the airplanes ground effect into F1 cars
LOTUS 78
- Designed by Colin Chapman
- Inverted airfoil shape
- High adherence in quick turns
Lotus 78-79 3. Bottom evolution through decades
3.1 70s: Birth of aerodynamics in F1
Introduction of the airplanes ground effect into F1 cars
Brabham BT46B
- Known as the “fan car”
- Extracted air from the bottom of the car
- The generated depression attached the car to the ground
Brabham’s fan car 3. BottomBottom evolution evolution through through decades decades
3.2 80s: The seek for safety
New safety regulations and standardization
Ban of the flexible skirts in the sidepods
More difficult to obtain ground effect 3. BottomBottom evolution evolution through through decades decades
3.2 80s: The seek for safety
New New modifications restrictions by the engineers
Safety was not improved and more deaths took place GROUND EFFECT WAS BANNED 3. Bottom evolution through decades
3.3 90s: Diffusers and flat bottoms
More stable behavior
Imposition of the flat bottom
Determined the car dimensions
The diffuser becomes the most important part
- Allows teams to increase the downforce generation
- Pressure difference generation along the underbody
Flat bottom and diffuser bottom shape 3. Bottom evolution through decades
3.3 90s: Diffusers and flat bottoms
BROWN’s revolutionary double diffuser
- Extracted air in a more efficient way - Increased negative pressure and downforce - Banned at the end of the season
Double diffuser design implemented by BROWN 3. BottomBottom evolution evolution through through decades decades
3.3 90s: Diffusers and flat bottoms
Newey’sNewey’sblowblow diffuser diffuser - Introduced more mass flow at the bottom of the car - Employed exhaust gases to re-energize the flow
Newey’s blow diffuser concept 4. ExperimentalExperimental measurements measures
Perform a comparison in terms of downforce generation
LOTUS 79 2017 F1 car
Inverted wing bottom layout Diffuser + flat bottom 4. ExperimentalExperimental measurements measures
4.1 Wind tunnel configuration
1. Ground effect simulation
Metallic plaque installed in the wind tunnel 4. ExperimentalExperimental measurements measures
4.1 Wind tunnel configuration
1. Ground effect simulation
2. Design of the model cars
- Limitations on the scale LOTUS 79 inverted wing shape
- Needed to find information about the actual dimensions
- Fulfillment of the geometric, kinematic and dynamic similarities
- Employment of the same upper surface for both cars 4. ExperimentalExperimental measurements measures
4.1 Wind tunnel configuration
1. Ground effect simulation
2. Design of the model cars
- Limitations on the scale 2017 diffuser and flat bottom layout
- Needed to find information about the actual dimensions
- Fulfillment of the geometric, kinematic and dynamic similarities
- Employment of the same upper surface for both cars 4. ExperimentalExperimental measurements measures
4.1 Wind tunnel configuration
1. Ground effect simulation
2. Design of the model cars
3. Wind tunnel limitations
Scale Speed Vibrations
Only able to replicate 4 km/h of real speed 5. ObtainedObtained results results
5.1 Downforce
Downforce LOTUS 78 Downforce 2017 car 0,1
0 0 5 10 15 20 25 30 35 -0,1
-0,2 Lotus 78 shows a greater evolution -0,3
-0,4 2017 car generates a higher downforce for lower airspeeds
-0,5 Downforce (N) Downforce
-0,6
-0,7
-0,8 Air speed (m/s) 5. ObtainedObtained results results
5.2 Drag
Drag LOTUS 78 Drag 2017 car 1,8
1,6
1,4
1,2 Approximately the same drag force 1
0,8 Low influence of the bottom layout
Drag (N) Drag in the drag generation 0,6
0,4
0,2
0 0 5 10 15 20 25 30 35 Air speed (m/s) 5. ObtainedObtained results results
5.3 Analysis of the results
Perform a comparison in terms of downforce generation
Better behavior of the LOTUS 79
Yes
Proved that the inverted wing configuration gives a greater downforce 5. ObtainedObtained results results
5.3 Analysis of the results
Perform a comparison in terms of downforce generation
Better behavior of the LOTUS 79
No
OVERSIZED DIFFUSER What happened with the results? 65.. ObtainedConclusions results
Different configurations of the bottom along the years
Improvements on the ways of generating downforce according to the imposed restrictions
The effect of the wing car can be replicated with an oversized diffuser and flat bottom configuration OVERSIZED DIFFUSER Thank you so much!
Jorge Arnedo García – [email protected] Miguel Andrés Masip – [email protected] Lucas Bernácer Soriano – [email protected] Francisco García Villanueva – [email protected]