Simulating a lap

In F1 world anything that can help you make the car better is welcome. This time we will talk about software simulators and in particular, showcase the one from Ansible Design. It's called AeroLap and is able to simulate a whole lap given certain car parameters and even take environmental factors into account. This entire article would have not been possible without the kind cooperation from the people at Ansible Design, Woking, UK.
This software has been used successfully for years throughout all kinds of motorsport divisions, including existing F1 customers.

AEROLAP

How it works

Using a complex, multi-layered model with many non-linear components, and performing hundreds of thousands of calculations for a run AeroLap can provide more realistic and accurate results than other methods.
The underlying calculation method is to discretise a given 3D path into small segments. For each segment the maximum thrust is applied to the car, according to the authority of the engine or braking system and limited by the grip available, driver behaviour and other forces on the car e.g. aero or gravity. A pseudo steady state solution is found for the sprung mass position and the solver focus moves to another segment. Segments are solved in the most efficient order, which is often not sequentially. When all segments have been solved the results can be presented as a continuous time history.

How the teams are using it

• Decide race engineering strategy before going to the track.
• Prepare your setups in advance for changes in track layout, or for going to a new track.
• Make key design decisions before committing to building a prototype.
• Choose gear ratios based on their effect on laptime, automatically taking account of many factors that are not considered when using ratio charts or spreadsheet modelling such as engine performance, track gradients, ambient wind speed.
• Compare different engine torque/power curves, both in terms of predicted lap time and by plotting the engine torque or power actually being used throughout the lap.
• Run a variety of aerodynamic trims and look at lift/drag trade-offs.
• Predict ride heights and alter the suspension setup so that you are getting the best out of the car's aerodynamics.
• Examine the effect of different fuel loads on performance for pit strategy.
• Setup your suspension to get the best from the tires.
• Gain a better understanding of what affects your car's performance and why.

They say picture is worth a thousand words, so instead of describing all parameters that can be modified I will feature them in a series of screenshots. The sample data we have available is for Le Mans car and track layout, but assume that track data can be modified to match precisely each of the F1 tracks, just as well as car parameters. Let's dive in and don't be scared by the amount of numbers - these are all vital parts of car setup. The article itself could always be updated to include even more screens.

Parameters
Define and setup a model of car - you can choose parameters for:

1.  Aerodynamics - reference frontal area, front and rear downforce, wind tunnel offsets, etc. This data can be also generated from AeroContour software, which is going to create the aero maps. Example:
   
   This is the one displaying downforce related to front and rear ride height, here's also one showing the drag:
   
2. Chassis
   Defining the physical dimensions of the car, masses - front, rear and even mass on the grid (assuming driver plus fuel)

   

   Mass

   

   Dimension

3. Suspension
   
   
4. Tires
   
   
   This includes data for all four tires
5. Gearbox
6. Environment factors
   
   
7. Engine data
   
   
8. Track data
   

Finally, as soon as we have all the input parameters set, we can hit the big Play button, which activates the solver and interactively the little yellow circle (the car) moves around the track. On a moderate normal desktop PC the simulation took around 8 seconds and the result looks like this: 

Other charts and graphs that are useful to data engineers are various parameters which progress as the lap advances, such as Speed vs. Lap or Torque / Engine RPM vs. Lap.
Here's an example:

On this final tab where you see the results of the simulation, there are multiple channels to select from, i.e. you can overlay the Speed vs. Aero drag, in our case labeled as Cd (coefficient of drag):

Quite obviously, the drag increases as the speed goes up. In the same manner multiple parameters can be displayed, derived from the base suspension, chassis, tires, aerodynamics, etc. These results are also available in table format as data values, so that you can export them and pass the output to another chart-drawing software. 

Finally, we would like to have a look at our results and revisit the strategy for the race. Back to the suspension module gives us the option to change the ride height from 65 mm to another value, I will select 80 and then re-run the simulation. The results are clear from this simple change: 

We lost about 0.7 seconds for the whole lap, and this is a clear indicator that increased ride height is perhaps not the most optimal strategy. In the same fashion you can tune and play with all available parameters, check the results and decide what to do. Again, this gives precious insight to race engineers, designers and aero people to make early predictions on what direction to follow when building / modifying a car, as well as create and adjust racing strategies. 
Aerolap, as a mature software, has a lot more to offer, for example integration with software from the same breed, such as AeroSusp or AeroContour to literally any kind of motorsport division. 

Thanks for attending, questions are always welcome. 

F1 car setup

Hello and thanks for tuning in.

The goal of the following article is to give an overview, as well as two interesting pictures, to the reader in regards to Formula 1 car setup - and a rough idea of the complexity that every team/driver has to cope with.
Note: Some of you may be more advanced in F1's technical matters, so to some extent you may be familiar with the information below. But I'm sure you'll like the pictures.

Probably quite often you hear from a driver after the race: "For some reason, we couldn't get the balance right with the current setup and I was struggling on every fast|slow corner".
Conventional racing wisdom says that the car setup is a balance between different things, but sometimes could be a trade-off, too, for example, if you want to overcome certain shortcomings of your design, e.g. running "more wing" to compensate for lack of downforce.

Let's dive into the details about on-track settings. 

• Tires - A bit aside from tire optimal working temperatures, depending on the compound (90 - 125C), a word about the pressure. Usually, they (the tires) are filled with a special, nitrogen-rich air mixture, designed to minimise variations in tyre pressure with temperature. The mixture also retains the pressure longer than normal air would.
  The tire manufacturer would provide the teams with a limits for variation, so it will be up to the race engineers to decide, because incorrect values may simply ruin the car's performance.
  A typical average pressure number would be 19 psi.
• Suspension - There are couple of settings and terms I'd like to highlight:
  Camber, caster, toe, rear and front ride height and rake.
  
  - Camber - That's the angle between the vertical axis of the wheels and the vertical axis of the vehicle when viewed from the front. In a simple picture, that looks like this (negative camber):

  

  Ferrari F150 - Negative Camber Tire setting
  (click for larger image)
  Photo credit: http://ferrari.com/

  
  Negative camber merely means that both wheels are inclined inwards at the top, as seen above on Ferrari F150. If you are looking for a typical ballpark number, that would be for example 3 degrees, i.e. the wheels are inclined inwards by 3 degrees compared to the center line.
  
  - Caster - That's the angle to which the steering pivot axis is tilted forward or rearward from vertical, as viewed from the side.
  Just have a look at any shopping cart wheel to understand what this is.
  As it can be seen from the final two images below, teams can use figures from 9 to 12 degrees, for example.
  
  - Toe - If you look a car from above, a pair of wheel can have their leading edges pointed to each other - this is Toe-In, whereas opposite - edges away from each other, that's Toe-out. Again, let's use Mclaren 's 2012 competitor, MP4-27, to demonstrate this:
  

  

  Mclaren MP4-27 (click for larger image)
  Photo credit: http://www.mclaren.com/mp4-27

  
  On the left, that's the axis showing Toe-In, only in case where both wheels are aligned the same direction (V like shape).
  Similarly, the opposite is true for the right axis, which is Toe-Out. (Like Lambda ( λ ), from the Greek alphabet).
  More details on what Toe setting can bring in the comment section of the post.
  
  - Rake, ride height - Both are related, but put simply, rake is the car’s attitude from front to rear. Such setup should, in theory, increase the diffuser exit area, and thus increase rear downforce, for example, but it's not that simple, because there are number of settings to take into account, like suspension geometry, overall aero setup, induced oversteer from stiff rear suspension, etc.
  Example or rake here (image link @  http://scarbsf1.wordpress.com Mclaren MP4-27).
  In both pictures below you can see real numbers for rear and front ride height (in mm.)
• Engine maps/modes
  - Map is rather a high-level term describing variations of fuel strategies, ignition timing, torque settings and so on, whereas mode (or mix) is more like a setting for being inline with race demands, like fuel saving and proper amount of power.
  
  Examples of team communicating those are:
  Red Bull telling Vettel: " torque map 5 "is available", while Mercedes say to MSC:  "torque mode 3"
  
  It won't be unusual to hear race engineer on the radio: "Engine 2, mix 5" on the start - they use those values to communicate with the driver the proper settings throughout the course of the race.
  
  Example of engine software modification was the infamous "Off-throttle blown diffuser" employed last year mainly by Renault-powered engine teams.
  Small hint about how the things could be done here - software / automotive engineers will know the answer to that riddle.
  
  - Gear ratios - While real numbers can be seen in Arrows A22 picture below, we should note that this setting can really make a difference. For example, back in 2011 season it was quite evident that Sebastian Vettel had shorter 7th gear choice for Monza - a move which had its merit, namely for better acceleration out of the corners. It was a bit of a gamble, too, because Vettel was assuming that he would lead right from the start and won't need to overtake anyone. His top speed was affected, too, but it played well for him in the end.
  
  
• Differential - Among one of the most important things that driver can control from the cockpit. An example of its importance is the end of the race, where the fuel levels are going down, and car starts to behave differently, so alterations are needed.
  On average of 5 laps there is at least one adjustment, though sometimes drivers are doing it from one corner to another.
  The settings are usually a numbers, just as Rosberg was advised to try "mid-corner diff 7 setting" in Valencia FP2. 
• Angle of attack (AoA) - That's something pretty self-explanatory - it's related to the more or less extreme angles of a wing, for example, aimed to achieve respectively downforce or high-speed.
  The efficiency of a wing is its downforce/drag ratio - more downforce (or lift) typically comes at the cost of more drag and lower top-speed. The greater the angle of attack, the more downforce and drag.
  
  A while ago (2010), a mechanism for changing the angle of attack of the front wing was available for drivers, but in 2011 this was no longer allowed.
  
  Illustrated nicely with the following image, F2012 front wing:
  
• More on aerodynamics is coming here, in the blog, as well as other places, in the next few months - not general aerospace, but Formula 1 related.
• Brake balance / bias - Often adjusted by the driver from the steering wheel. During the race, the brakes can worn to some extent, for example, and in order to avoid instability during braking, the pilot can switch the bias from rear to front or vice-versa. In some cases the brakes can experience extreme overheat (thermal runaway), being loaded with values between 400C and up to 1000C.
• Ballast - Usually plates from high density metal like tungsten steel. Often planted on places where balance and in particular weight in small available space is needed.
  One piece of it usually fits on your palm, and could weight about 11 kg.

And finally to the promised pictures. I found the first one in Ebay a while ago, screenshot it, but the original URL is no longer present.
It's a setup sheet of Arrows A22 - a car that competed back in 2001.

"Arrows A22" car setup 2001

And here's a more recent one. Prior to joining back the F1 madness in 2012, Kimi R. had to complete a "smoke-test" with an old Renault car, namely R30.

Renault R30 - Kimi in pre-2012 private test
Photo credit: http://f1news.cz

These are real numbers from the notebook of his race engineer and that's part of the amount of data that goes into F1 car setup.

Finally, there's a picture available with a team race weekend program, Toro Rosso were generous enough not to hide the sheet from curious eyes. While it's not exactly a car setup, it still gives a good overview of how many of the described permutations are being tried on Friday alone. The picture is from Monza, 2012:

Larger version available, image courtesy of http://f1.f-e-n.net

Thanks for reading all the way down. These are some of the important pieces that take place in a Formula 1 car setup. I'd love to hear more from you, in case I missed something significant, or just a general feedback.
Cheers.