The list doesn't pretend to be exhaustive or fully descriptive on certain topics, such as CFD, but for now I'd prefer the simpler variant, listed alphabetically for easier navigation. Additions and comments are appreciated , but at the same time I will assume that you know the basics, for example the fact that there are four forces that act on a car: lift, weight, thrust, and drag.
The format is simple:
- TERM
- Explanation
- Illustrated picture (almost all have larger sizes)
AIRFOIL
[Explanation] In British English you can also find the term as "Aerofoil", but generally this is a transverse cross-section of a wing. This is how the term is named in all aerospace sources, but in motorsport that's just another word for wing or its shape.
[Picture] To follow below, when explaining Angle of attack
ANGLE OF ATTACK
[Explanation]
This is the angle between airfoil's chord line and the crosswind airflow, regardless of wing's direction.
[Picture]
 |
| image credit: http://wikipedia.org |
ASPECT RATIO
[Explanation] The ratio of the length of wings to their width is called aspect ratio. A high aspect ratio indicates long, narrow wings. A low aspect ratio indicates short, wide wings.
In short, a simple formula to present it mathematically:
Aspect ratio = wing length / wing width
BARGEBOARD
[Explanation]
Bodywork piece on an open-wheel race car, which is usually situated between the front wheels and the sidepod. They, the bargeboards, are usually created with trapezoid profile, and their main task is to redirect turbulent air (flow conditioners), from the wake of the front wing, tires and suspension.
Another function of bargeboards is to serve as vortex generators, for example, creating and directing a quite fast vortex around the sidepods.
[Picture]
BERNOULLI'S PRINCIPLE
BOUNDARY LAYER
[Explanation]
When an object moves through a fluid or gas the molecules of the fluid near the object are disturbed and aerodynamic forces are created, whose magnitude is dependent on fluid's viscosity and its elasticity.
The former is very important, as the molecules right next to the surface of the object are sticking to it. Then, there's a collision between molecules sticking to the surface and those above it - this creates a tiny layer with 0 to very small velocity which is called Boundary layer.
Boundary layers can be Laminar or Turbulent, which are covered below.
[Picture]
CAMBER (ANGLE)
[Explanation]
Misdirection such as "camber is the top surface of a wing" do exists, but in fact if we look previously at Angle of Attack's picture, we will notice that one of the surfaces is just more curved than the other - than it's said that the airfoil has camber, while the camber angle is the difference between the chord line (red) and camber line (blue).
COMPUTATIONAL FLUID DYNAMICS (CFD)
[Explanation]
CFD is a leaf on the large tree of fluid mechanics which uses numerical and computational methods to solve issues arising during fluid flow.
It is important to note that typical CFD simulation offers approximations and assumptions by solving Navier–Stokes equations, which define any single-phase fluid flow. Recently there is a lot of interest in two or multiphase models.
F1 teams would usually use CFD along with wind tunnel testing to correlate the produced data and produce parts with greater confidence, having done simulations prior to actual fabrication and production. Such simulations often require large computing power in order to complete as fast as possible.
Generally, a CFD task usually consists of three main stages:
[Picture]
DOWNWASH
[Explanation]
The downwash effect is simply an air which is forced down - due to wing trailing edge or due to the shape of the body in general. In case of downforce inducing airfoil, the downwash occurs in front of the wing.
Video with downwash effect on a finite wing can be seen below, at Wake section.
[Picture]
END PLATE
[Explanation]
In order to overcome the problem of turbulence created between the front wheels and the front wings, end plates have been introduced (blue color on the picture below). During the years they had different shapes, but have been used to redirect air away from the tires, and also as pressure equalizers (at rear wing), having in mind the usual wingtip vortices.
[Picture]
FLAP
[Explanation]
The front wing of F1 car consists of end plates, center section, cascade elements and main flap, highlighted in blue on the picture below. Generally, there's a slot gap between each of the elements, in order to keep the air as attached as possible, thus prevent stall and flow separation. This flap is the element that determines the angle of attack of the front wing, it is adjustable, and therefore it is very important part.
[Picture]
GURNEY FLAP (WICKERBILL)
[Explanation]
That term originates back in 1970's where American Dan Gurney was fixing this small device at the trailing edges of the wings on racing cars. This is really an effective way to increase the downforce of a wing at the expense of small drag induced. Different researches are quoting different numbers, but let's throw some average numbers and give a ratio of 8% more downforce vs. 3% increase in drag.
What is actually little known as fact is that Gurney flap increases lift by changing the Kutta condition (related to sharp trailing edges), so the wake behind the flap are two counter-rotating vortices (also very typical to diffuser lateral edges, where Gurney flaps are present, too).
[Picture]
OR
LAMINAR FLOW
[Explanation]
Laminar flow is sometimes also known as streamline flow, occurs when fluid flows in a parallel uninterrupted layers. The main characteristics of laminar flow are its smoothness, the lack of swirls or vortex formations (as much as possible), steady velocity and hence stable pressure gradients.
Few more lines below we are going to talk about Reynolds number, but generally laminar flow is characterized with low Reynolds number (Re).
[Picture]
LIFT TO DRAG RATIO
[Explanation]
Most commonly you will find this term abbreviated as L/D ratio or simply Ld - is the amount of lift (or downforce) generated by a wing or vehicle, divided by the drag it creates by moving through the air.
That ratio has lots of components that build it, but for now we will skip the math and the formulas, and will conclude that in F1 engineers are always trying to achieve higher downforce at lower drag coefficients, which is usually a result of a balancing act - in either setup or design stage.
PITCH SENSITIVITY
[Explanation]
While in motion, certain aerodynamic forces act on a race car. The magnitude of those forces is commonly known as pitch movements, and the ability of the car to cope with them is know as pitch sensitivity. That ability is directly related to the way the car feels and handles, for example sudden and excessive diving nose when braking. More can be seen below at Yaw paragraph.
REYNOLDS NUMBER
[Explanation]
Reynolds number can be frequently seen when solving fluid dynamic issues, just as well as characterize different flow modes, such as laminar or turbulent flow. It is generally a ratio of inertial to viscous forces.
For example, at high Reynolds number the flow is turbulent, characterized by unstable formations, such as eddies and vortices, while at low Reynolds number the flow is laminar (usually smooth flow).
Reynolds number as a measure is very useful for aerodynamic engineers which are trying to match data produced by wind tunnels testing with real track data. This is also one the very possible reasons for data correlation mismatch (a popular topic in F1 world) - the Reynolds number is different on a wind tunnel scaled-down model and real car, because the boundary layer is different.
where:
Laminar flow: Re < 2000
Transitional flow: 2000 < Re < 4000
Turbulent flow: Re > 4000
SLAT
[Explanation]
This is part of multi-element wing which is installed ahead of leading edge of the airfoil, below the main element. Certainly, it's there to create more efficiency and downforce. See picture below - a typical aircraft installment, imagine it reversed for a race car.
[Picture]
STRAKE
[Explanation]
A flat plate body fixed to race car in order to control and direct airflow (falls under the general category of Flow conditioners).
[Picture]
TURNING VANES
[Explanation]
The turning vanes on the picture below are rather Mclaren style, as opposed to the L-shaped from Red Bull and recent 2012 Ferrari incarnations. Turning vanes serve similar purpose to bargeboards, but are usually smaller in size. They started as very simple elements, like the ones highlighted with blue below, but have turned into increasingly complex in the recent years, given the strong aerodynamic profiles of modern Formula 1 cars.
[Picture]
VENTURI
[Explanation]
Here we will talk about both the effect and the tube, named after the Italian physicist Giovanni Battista Venturi.
The Venturi effect is a jet effect per se - in a tunnel the velocity of the fluid increases as the cross sectional area decreases, which is accompanied with a decrease of the static pressure.
In Formula 1 Venturi effect is closely related with underbody aerodynamics, which included shaped channels (before flat floors) aimed to accelerate the air and hence create low pressure areas.
See the picture below and imagine how and where can this be applied in a race car.
Again, the blue areas are low pressure ones and red are high.
[Picture]
VORTEX
[Explanation]
Vortex in aerodynamics is any fluid or gas formation which usually has turbulent flow. What is typical for a vortex is the low pressure at its core, which rises progressively as we go away from the center to the outer edges where the pressure is very high. This is one of the reasons why aero people generally would like to avoid creating vortices - the high pressure would mean lower velocity of the surrounding layers, thus drag.
Other reason why vortices are generally avoidable is because of the possibility of "vortex burst" - this is the moment where the formation literally breaks and creates even more turbulent and uncontrollable flow. This is less likely to happen with weak vortices and respectively, usually seen with strong vortices, where the core sometimes disintegrates into few smaller vortices.
The reason why, however, vortices are sometimes deliberately induced is to wake or re-energize the boundary layer - the small portion of air which is very close to a surface, where due to skin friction and resistance the velocity of the air is very low. We would like, as aero people, to have less drag, so we create a vortex generators - small winglets, which often induce normally rotating, weak vortices. The trade-off is the smaller portion of drag induced due to the shape of the device, but it's more beneficial in terms of L:D coefficient.
In F1 world we often hear the term referred to as "wingtip vortices", as seen on the picture below. The reason for creation of such formations is the natural tendency of the air to move from high to low pressure regions, being a continuous function. Here, since we operate with negative lift (downforce), the direction of the vortices is upwards.
These wingtip vortices, on the other hand, create lift-induced drag and drag is unwanted in any of its forms in motor sports, where speed matters.
[Picture]
VORTEX GENERATORS
[Explanation]
We have already explained what boundary layer is, so down on the alphabet we reached the vortex generators - small, usually vertical wings (or winglets, if you prefer - the synonym for small wing) whose purpose is re-energize the boundary layer, and thus increase the overall velocity of the air stream.
Generally, they are quite an easy way to direct air (flow conditioning) and enforce some turbulence close to the surface. In Formula1 cases we have even seen plastic-like Vortex Generators used on Toro Rosso's car - most probably a quick prototype parts, still, they do the job.
[Picture]
WAKE
[Explanation]
This is the turbulent disturbed air behind an object where the total pressure is low. Notice the 3D grid generated behind the wing's trailing edge below.
[Video]
YAW (PITCH AND ROLL)
[Explanation]
Yaw, in particular, is the motion of race car around a vertical axis, which occurs for example during steering.
All three directions are shown below.
[Picture]
[Picture]
 |
| Image credit: http://NASA.gov |
BARGEBOARD
[Explanation]
Bodywork piece on an open-wheel race car, which is usually situated between the front wheels and the sidepod. They, the bargeboards, are usually created with trapezoid profile, and their main task is to redirect turbulent air (flow conditioners), from the wake of the front wing, tires and suspension.
Another function of bargeboards is to serve as vortex generators, for example, creating and directing a quite fast vortex around the sidepods.
[Picture]
 |
| Original concept: deus1066, Model remix: F1 Framework |
BERNOULLI'S PRINCIPLE
[Explanation]
In 1738 the Swiss mathematician Daniel Bernoulli publishes in his book, Hydrodynamica, the principle stating that an increase in a fluid's speed occurs simultaneously with accompanying decrease in pressure or decrease in fluid's potential energy.
Here we see very close relations and roots with the Conservation of Energy principle, as well as Newton's 2nd law.
Here we see very close relations and roots with the Conservation of Energy principle, as well as Newton's 2nd law.
BOUNDARY LAYER
[Explanation]
When an object moves through a fluid or gas the molecules of the fluid near the object are disturbed and aerodynamic forces are created, whose magnitude is dependent on fluid's viscosity and its elasticity.
The former is very important, as the molecules right next to the surface of the object are sticking to it. Then, there's a collision between molecules sticking to the surface and those above it - this creates a tiny layer with 0 to very small velocity which is called Boundary layer.
Boundary layers can be Laminar or Turbulent, which are covered below.
[Picture]
 |
| Image credit: NASA.gov |
CAMBER (ANGLE)
[Explanation]
Misdirection such as "camber is the top surface of a wing" do exists, but in fact if we look previously at Angle of Attack's picture, we will notice that one of the surfaces is just more curved than the other - than it's said that the airfoil has camber, while the camber angle is the difference between the chord line (red) and camber line (blue).
COMPUTATIONAL FLUID DYNAMICS (CFD)
[Explanation]
CFD is a leaf on the large tree of fluid mechanics which uses numerical and computational methods to solve issues arising during fluid flow.
It is important to note that typical CFD simulation offers approximations and assumptions by solving Navier–Stokes equations, which define any single-phase fluid flow. Recently there is a lot of interest in two or multiphase models.
F1 teams would usually use CFD along with wind tunnel testing to correlate the produced data and produce parts with greater confidence, having done simulations prior to actual fabrication and production. Such simulations often require large computing power in order to complete as fast as possible.
Generally, a CFD task usually consists of three main stages:
- Pre-processing - where geometry is defined, the total occupational volume of the fluid is divided into cells - mesh creation, as well as physical models and boundary conditions;
- Solving - the actual process of iteratively solving the conditions of each cell;
- Post-processing - the stage where the results for each calculations are being analyzed and then presented in a readable form, usually like the picture below.
In most of the cases the red color zones will mean high pressure, while the blue is the opposite - low pressure regions.
 |
| ANSYS Fluent pressure gradients in polyhedral mesh |
[Picture]
 |
| Image courtesy: Voxdale In this particular case, the colors stand for velocity - red is high, blue is low. |
DOWNWASH
[Explanation]
The downwash effect is simply an air which is forced down - due to wing trailing edge or due to the shape of the body in general. In case of downforce inducing airfoil, the downwash occurs in front of the wing.
Video with downwash effect on a finite wing can be seen below, at Wake section.
[Picture]
 |
| Original concept: deus1066, Model remix: F1 Framework |
END PLATE
[Explanation]
In order to overcome the problem of turbulence created between the front wheels and the front wings, end plates have been introduced (blue color on the picture below). During the years they had different shapes, but have been used to redirect air away from the tires, and also as pressure equalizers (at rear wing), having in mind the usual wingtip vortices.
[Picture]
 |
| Original concept: deus1066, Model remix: F1 Framework |
FLAP
[Explanation]
The front wing of F1 car consists of end plates, center section, cascade elements and main flap, highlighted in blue on the picture below. Generally, there's a slot gap between each of the elements, in order to keep the air as attached as possible, thus prevent stall and flow separation. This flap is the element that determines the angle of attack of the front wing, it is adjustable, and therefore it is very important part.
[Picture]
 |
| Original concept: deus1066, Model remix: F1 Framework |
GURNEY FLAP (WICKERBILL)
[Explanation]
That term originates back in 1970's where American Dan Gurney was fixing this small device at the trailing edges of the wings on racing cars. This is really an effective way to increase the downforce of a wing at the expense of small drag induced. Different researches are quoting different numbers, but let's throw some average numbers and give a ratio of 8% more downforce vs. 3% increase in drag.
What is actually little known as fact is that Gurney flap increases lift by changing the Kutta condition (related to sharp trailing edges), so the wake behind the flap are two counter-rotating vortices (also very typical to diffuser lateral edges, where Gurney flaps are present, too).
[Picture]
 |
| Original concept: deus1066, Model remix: F1 Framework |
LAMINAR FLOW
[Explanation]
Laminar flow is sometimes also known as streamline flow, occurs when fluid flows in a parallel uninterrupted layers. The main characteristics of laminar flow are its smoothness, the lack of swirls or vortex formations (as much as possible), steady velocity and hence stable pressure gradients.
Few more lines below we are going to talk about Reynolds number, but generally laminar flow is characterized with low Reynolds number (Re).
[Picture]
LIFT TO DRAG RATIO
[Explanation]
Most commonly you will find this term abbreviated as L/D ratio or simply Ld - is the amount of lift (or downforce) generated by a wing or vehicle, divided by the drag it creates by moving through the air.
That ratio has lots of components that build it, but for now we will skip the math and the formulas, and will conclude that in F1 engineers are always trying to achieve higher downforce at lower drag coefficients, which is usually a result of a balancing act - in either setup or design stage.
PITCH SENSITIVITY
[Explanation]
While in motion, certain aerodynamic forces act on a race car. The magnitude of those forces is commonly known as pitch movements, and the ability of the car to cope with them is know as pitch sensitivity. That ability is directly related to the way the car feels and handles, for example sudden and excessive diving nose when braking. More can be seen below at Yaw paragraph.
REYNOLDS NUMBER
[Explanation]
Reynolds number can be frequently seen when solving fluid dynamic issues, just as well as characterize different flow modes, such as laminar or turbulent flow. It is generally a ratio of inertial to viscous forces.
For example, at high Reynolds number the flow is turbulent, characterized by unstable formations, such as eddies and vortices, while at low Reynolds number the flow is laminar (usually smooth flow).
Reynolds number as a measure is very useful for aerodynamic engineers which are trying to match data produced by wind tunnels testing with real track data. This is also one the very possible reasons for data correlation mismatch (a popular topic in F1 world) - the Reynolds number is different on a wind tunnel scaled-down model and real car, because the boundary layer is different.
The formula is simple:
- v = is the mean velocity of the object relative to the fluid (m/s)
- L = characteristic linear dimension, (travelled length of the fluid) (m)
- mu = is the dynamic viscosity of the fluid (Pa·s or N·s/m² or kg/(m·s))
- u = is the kinematic viscosity (v = mu / p) (m²/s)
- p = density of the fluid (kg/m³)
Laminar flow: Re < 2000
Transitional flow: 2000 < Re < 4000
Turbulent flow: Re > 4000
SLAT
[Explanation]
This is part of multi-element wing which is installed ahead of leading edge of the airfoil, below the main element. Certainly, it's there to create more efficiency and downforce. See picture below - a typical aircraft installment, imagine it reversed for a race car.
[Picture]
[Explanation]
A flat plate body fixed to race car in order to control and direct airflow (falls under the general category of Flow conditioners).
[Picture]
 |
| Original concept: deus1066, Model remix: F1 Framework |
TURNING VANES
[Explanation]
The turning vanes on the picture below are rather Mclaren style, as opposed to the L-shaped from Red Bull and recent 2012 Ferrari incarnations. Turning vanes serve similar purpose to bargeboards, but are usually smaller in size. They started as very simple elements, like the ones highlighted with blue below, but have turned into increasingly complex in the recent years, given the strong aerodynamic profiles of modern Formula 1 cars.
[Picture]
 |
| Original concept: deus1066, Model remix: F1 Framework |
VENTURI
[Explanation]
Here we will talk about both the effect and the tube, named after the Italian physicist Giovanni Battista Venturi.
The Venturi effect is a jet effect per se - in a tunnel the velocity of the fluid increases as the cross sectional area decreases, which is accompanied with a decrease of the static pressure.
In Formula 1 Venturi effect is closely related with underbody aerodynamics, which included shaped channels (before flat floors) aimed to accelerate the air and hence create low pressure areas.
See the picture below and imagine how and where can this be applied in a race car.
Again, the blue areas are low pressure ones and red are high.
[Picture]
 |
| Image credit: http://www.symscape.com |
VORTEX
[Explanation]
Vortex in aerodynamics is any fluid or gas formation which usually has turbulent flow. What is typical for a vortex is the low pressure at its core, which rises progressively as we go away from the center to the outer edges where the pressure is very high. This is one of the reasons why aero people generally would like to avoid creating vortices - the high pressure would mean lower velocity of the surrounding layers, thus drag.
Other reason why vortices are generally avoidable is because of the possibility of "vortex burst" - this is the moment where the formation literally breaks and creates even more turbulent and uncontrollable flow. This is less likely to happen with weak vortices and respectively, usually seen with strong vortices, where the core sometimes disintegrates into few smaller vortices.
The reason why, however, vortices are sometimes deliberately induced is to wake or re-energize the boundary layer - the small portion of air which is very close to a surface, where due to skin friction and resistance the velocity of the air is very low. We would like, as aero people, to have less drag, so we create a vortex generators - small winglets, which often induce normally rotating, weak vortices. The trade-off is the smaller portion of drag induced due to the shape of the device, but it's more beneficial in terms of L:D coefficient.
In F1 world we often hear the term referred to as "wingtip vortices", as seen on the picture below. The reason for creation of such formations is the natural tendency of the air to move from high to low pressure regions, being a continuous function. Here, since we operate with negative lift (downforce), the direction of the vortices is upwards.
These wingtip vortices, on the other hand, create lift-induced drag and drag is unwanted in any of its forms in motor sports, where speed matters.
[Picture]
VORTEX GENERATORS
[Explanation]
We have already explained what boundary layer is, so down on the alphabet we reached the vortex generators - small, usually vertical wings (or winglets, if you prefer - the synonym for small wing) whose purpose is re-energize the boundary layer, and thus increase the overall velocity of the air stream.
Generally, they are quite an easy way to direct air (flow conditioning) and enforce some turbulence close to the surface. In Formula1 cases we have even seen plastic-like Vortex Generators used on Toro Rosso's car - most probably a quick prototype parts, still, they do the job.
[Picture]
 |
| Original concept: deus1066, Model remix: F1 Framework |
WAKE
[Explanation]
This is the turbulent disturbed air behind an object where the total pressure is low. Notice the 3D grid generated behind the wing's trailing edge below.
[Video]
YAW (PITCH AND ROLL)
[Explanation]
Yaw, in particular, is the motion of race car around a vertical axis, which occurs for example during steering.
All three directions are shown below.
[Picture]
 |
| Original concept: deus1066, Model remix: F1 Framework |
Congratulations, you have been very patient :)
Once again, this is just a reference point to some of the aero-related terms and devices in Formula 1. Some that are not included in the list, one reason or another: diffuser, rake (article coming on that in the future, studying effect of diffuser angles and rake together), high velocity tunnels (ducts), F-duct like devices, NACA ducts (or "submerged inlets", due to their vortex-generating nature) but they will find their place at the F1 Framework in detailed articles.
As usual, I'm open to topic suggestions - next raft of blog posts are likely to be attributed to exotic technologies that can make it into F1.
