Respect wheel and ground interference
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Course: Engineer downforce you can actually use
Module: Shape the whole car's airflow
Estimated duration: 55 minutes
A race car does not move through clean air in the abstract. It moves close to a road, on rotating tyres, with wheel openings, suspension motion, underbody restrictions, and wakes that often reach the ground. That single fact changes how you should think about almost every aerodynamic device on the car.
The useful skill in this lesson is not designing a wing or choosing a diffuser angle in isolation. It is learning to ask where the air can actually go once the ground and wheels have interfered with it. If you ignore those two interference sources, you can make a part that looks powerful in isolation but feeds dirty, slow, blocked, or unstable flow into the rest of the car. If you respect them, you begin to shape the whole car as a connected pressure and flow system.
Start with the ground. Every car operates near the ground, so every car operates in ground effect in the broad sense. The surface below the car interferes with the underside flow simply because there is limited space between the car and the road. That interference can help you or hurt you. A front wing can make more downforce near the ground than it does in free air, but if it gets too close, the benefit can reverse and downforce can fall. An underbody can produce downforce only if it can keep useful attached flow moving through the floor and diffuser region. A rough or obstructed underside can instead create slow, turbulent flow and a thick boundary layer that reaches the ground, then merges into a wake that also reaches the ground.
That is the first principle: the ground is not a passive reference plane. It is one wall of the aerodynamic duct formed by the car and road. When the car moves up, down, pitches, rolls, or crests a rise, that duct changes shape. The pressure field changes with it. The driver may feel that change as balance shift, confidence loss, or a car that seems to gain and lose grip in a way that does not match steering, brake, or throttle input.
Now add the wheels. Wheels are not just blunt objects in the airstream. They rotate, contact the ground, sit partly inside bodywork or fully exposed depending on the car, steer at the front, and create separated flow around their perimeter. In an open-wheel car they can be a very large drag source and can also create positive lift. In a closed-wheel car they are shrouded from much of the outside air, but air still enters the wheel wells from the front, from underneath, and from the sides. The rotating wheel can behave like a pump inside a semi-enclosed wheel well, increasing the importance of where the air exits.
That is the second principle: a wheel is a moving disturbance, not a static lump. Its wake, pumping action, yaw sensitivity, and steering angle can spoil the air that later devices need. The front wheel wake is especially important because it reaches everything downstream. If the front wheels contaminate the side flow, the underbody feed, or the rear device inlet, the loss may appear far away from the wheel that caused it.
For you as a driver or track-side engineer, respecting wheel and ground interference means learning to diagnose aero behavior by flow path, not by part name. Do not ask only whether the car has a splitter, diffuser, wing, louvre, cutaway, or duct. Ask whether the air reaching that part is clean enough, energetic enough, and given a real exit path. Also ask whether the car keeps that flow condition when ride height, pitch, roll, yaw, and speed change. A car that works only in a static setup photo is not a race car setup. It has to work while braking, turning, accelerating, and running over crests.
The underbody lesson begins with the ordinary passenger car shape because it shows the penalty clearly. A typical road-car underside has exhaust, suspension, transmission, drivetrain, fuel tank shapes, engine and transmission cavities, and wheel wells interrupting the flow. Those protrusions and cavities create roughness. Roughness thickens the boundary layer under the car and tends to drag the air along with the car. At the rear, that thick underbody layer merges into the wake. The flow under the car is then slow, turbulent, and sometimes effectively blocked. Static pressure may be lower than ambient in places, but the system is losing too much energy to be a strong downforce producer.
The alternative is not simply low pressure. The alternative is fast, attached underbody flow with fewer losses. If the air can move quickly through the underbody region, static pressure can be reduced more usefully. That can reduce, cancel, or reverse the positive lift normally associated with a passenger-car shape. The difference is energy management. Slow, turbulent, obstructed air is not the same as fast, low-pressure, attached air.
This matters because many club cars begin life closer to the rough-underbody example than the prototype example. You may bolt on a front splitter, add a rear wing, or install a diffuser, but those parts still live in the actual flow environment of the car. A splitter that feeds a chaotic underside will not behave like a splitter feeding a clean floor. A diffuser behind a rough, obstructed mid-floor cannot be judged only by its exit angle. The air has to arrive with enough speed and organization to stay attached.
The first sub-skill is identifying the real underside path. Trace the air from the front of the car to the rear. Look for the first places where flow is blocked, slowed, or dumped into cavities. Ask what the front wheels are doing to the air entering the floor. Ask whether the floor has a clean central path or whether protruding mechanical parts dominate the underside. Ask whether the rear wake reaches the ground. If the wake reaches the ground, rear-body separation and underbody flow are interacting strongly, and base drag cannot be treated as a separate rear-only problem.
The second sub-skill is separating low static pressure from useful underbody work. A messy underside can contain locally low pressure, but the important question is whether the car is making stable vertical load with tolerable drag and consistent balance. Useful underbody downforce needs attached flow. If the floor or diffuser becomes separated, blocked, or over-sensitive to height, the pressure map may no longer produce a dependable load distribution.
The third sub-skill is connecting ride height and rake to the pressure system. Ground clearance changes the underbody cross-sectional area. Rake changes the shape of the underbody duct. A flat floor with a rear diffuser can be very sensitive to small ground-clearance and rake changes, especially when clearances are small. A stepped bottom can be less sensitive because the raised outer underbody sections see less cross-sectional-area change as the car moves vertically. The point is not that one layout is always better. The point is that the car moves, so the pressure system moves.
This is where intermediate drivers often misread aero balance. They feel entry understeer at high speed and call it a front grip problem. It may be, but it can also be a front-wing or splitter proximity problem, a ride-height problem, or a pitch-sensitivity problem. They feel rear instability over a crest and call it bravery or tire confidence. It may be, but it can also be an underbody and rake problem if the car is momentarily forced into an unfavorable attitude. A setup that produces strong platform-sensitive downforce can punish the driver exactly when speed, compression, cresting, or braking pitch changes the car height and angle.
Pitch sensitivity is the warning sign. In motion, the car rolls, pitches, and yaws on the suspension. Speed changes alter downforce, which changes ride height, which changes proximity to the ground and angle of attack for devices near the ground. That creates a feedback loop. The aero load changes the platform; the platform changes the aero load. If the load changes smoothly and predictably, the driver learns it. If the load changes sharply, the car becomes harder to trust.
The severe case is a front device run too close to the ground. At low dynamic ride height the front wing can stall. Downforce falls quickly, the nose rises, airflow reattaches, downforce returns, and the nose is pulled down again. The cycle can repeat as porpoising. Even if your track-day car is not a ground-effect Formula 1 car from the 1980s, the lesson still applies: devices near the ground can have a useful operating window, and closer is not always better.
The fourth sub-skill is treating device height as an operating window, not a single static number. Static ride height in the paddock is only the beginning. The real question is dynamic height at speed, in braking, in pitch, and over surface features. If a splitter, front wing, floor, or diffuser works only when the car is parked or only in one narrow speed band, it is not giving the driver stable information. Good aero balance is not just peak downforce. It is downforce the driver can believe.
The wheels complicate the same picture. On open-wheel cars, wheel airflow is one of the dominant problems. The wheels create substantial drag and often positive lift. The flow over, around, and especially behind them is hard to predict because the wheel is rotating, touching the ground, steering at the front, seeing yaw angle, and shedding separated flow. If a test method does not rotate the wheels, its measurements can mislead. If a CFD model treats the wheels too simply, it can miss the core disturbance.
This explains why open-wheel cars spend so much design effort around the front wheels. The front wheel wake is upstream of the rest of the car. Bargeboards, deflectors, flip-ups, endplate devices, sidepod features, and narrow central body sections are not decoration. They are attempts to manage where the wheel wake goes, give air a path between the wheels, and reduce drag while protecting downstream devices. Some features also deflect air over or around the wheels and may induce downforce, but the deeper idea is flow management.
For a driver, the practical implication is that steering angle is an aero input on an open-wheel or prototype-style car. More steering angle does not only ask the tire for more lateral force. It also changes the front-wheel wake and yaw relationship. If you scrub the front tires, hold unnecessary steering, or enter a corner with large corrections, you may also be feeding worse air to the car behind the front axle. The stopwatch may show the loss later in the corner or down the next straight, not exactly where you added the steering.
On closed-wheel cars, the wheels are partly shielded, but the problem does not disappear. Bodywork reduces the direct effect of the outside stream on the wheels, especially away from the lower region near the ground. Yet air still enters the wheel wells from several directions. Once inside, it has to go somewhere. A rotating wheel in a semi-enclosed wheel well can pump air, and the effect increases with speed. That can raise wheel-well pressure and create lift if the pressure is trapped under a curved wheel arch.
That is why louvres, cutaways, and ducts matter. Louvres on the top of sports prototype wheelarches help reduce the pressure difference between low static pressure over the curved arch and higher static pressure inside the wheel well. Side cutaways behind the front wheels help air leave the wheel wells and can also help air escape from under the whole front of the car. These features can work with front splitters and diffusers because they provide exits for air exploited farther forward.
The fifth sub-skill is asking whether wheel-well air has an exit path. If the car has a front splitter but trapped front wheel-well pressure, the splitter is working in a compromised environment. If the car has front fender louvres but the wheel-well inlet path is uncontrolled, the louvres may relieve pressure but still leave downstream flow messy. If a side cutaway dumps air into a region feeding the rear tire or side of the car, it may solve one problem and create another. The lesson is not to add vents everywhere. The lesson is to respect entry, pressure, and exit as one connected system.
Ducts belong in the same conversation. Many systems need air: radiators, brakes, electronics, and engine induction. Pulling air from the external stream can create drag, and careless cooling layouts can add lift. A duct is a way to use the energy of the airflow to do the necessary cooling or feeding job with smaller aerodynamic losses. But a duct is still a flow path. It has an inlet, a pressure recovery or restriction region, and an exit. If the exit dumps into a sensitive underbody or wheel-well zone, the duct may damage the aero map even while cooling well.
This is the sixth sub-skill: do not treat cooling air as free. Air used for brakes, radiators, electronics, or induction has been diverted from somewhere and must be returned somewhere. In wheel and ground interference work, the exit is often the overlooked half. A brake duct may cool the rotor but add to wheel-well pressure. A radiator outlet may reduce cooling drag or may feed a bad wake region. A cutaway may relieve under-front pressure or may dirty the side flow. The correct judgment is not whether a hole exists, but whether the whole duct path reduces losses while preserving the pressure fields you need.
The diffuser brings the lesson together because it depends on both ground proximity and downstream help. A short diffuser with a steep angle would normally be at risk of losing attached flow. But on some competition cars, a rear wing, especially a lower element, can have a strong beneficial effect on the underbody. The low static pressure under the rear wing interacts with the diffuser flow and can help it work. Pressure plots discussed by Katz showed that adding a rear wing improved under-car static pressure across different vehicle types, and the effect extended well forward, increasing integrated downforce over the underbody.
This is not a reason to think the rear wing fixes everything. It is a reason to stop thinking of the diffuser as a stand-alone ramp. The rear wing can help the diffuser. The diffuser can influence the rear wake. The floor flow depends on front feed and ride height. Wheel wakes can spoil that feed. Wheel-well exits can help or hurt the front-underbody region. The car is one flow system, but this lesson narrows that idea to the two disturbances most likely to be underestimated: the road under the car and the wheels beside it.
A useful mental model is to picture three air streams trying to coexist. The first is the underbody stream, squeezed between car and ground. The second is the wheel stream, disturbed by rotation, contact patch, steering, yaw, and cavities. The third is the external body stream, including the pressure over fenders, cockpit, arches, sidepods, rear body, and wing. Performance comes from managing how those streams meet. Losses come from pretending they do not meet.
When you inspect a car in the paddock, start at the front. If it is open-wheel, look at how the body and deflectors manage the front wheel wake. Is air being given a path between the wheels, over the wheels, around the wheels, or into the side of the car? If it is closed-wheel, look into the front wheel well and ask how air enters and exits. Look at the arch, louvre, side cutaway, under-front exit, and any brake duct path. Then look under the car and ask whether the floor can actually move air rearward with reasonable attachment.
Next, look at the dynamic platform. Is the car likely to run very low at speed? Does braking pitch put the front device close to the ground? Does acceleration or cresting risk rear-down or nose-up attitude changes that alter the underbody? Does the suspension have enough platform control to keep the aero map consistent? The source material describes third elements, springs, dampers, and damping systems that separate slower vehicle attitude changes from faster wheel movements. You do not need to become a damper engineer to use the lesson. You need to understand that suspension platform control and aerodynamic consistency are linked.
Then listen to the driver language. A driver who says the car is fine at medium speed but vague or nervous at high speed may be describing aero sensitivity. A driver who says the front bites, releases, then bites again may be describing a platform or front-device operating-window problem. A driver who says the car is strong in smooth high-speed corners but loses trust over crests may be describing ride-height, rake, or pressure-system change. A driver who says straight-line speed is poor after a bodywork change may be describing wheel drag, wheel-well pressure, cooling drag, or a wake penalty.
Calibration cues should be specific. On track, good wheel and ground interference management feels like aero load that builds with speed without sudden balance reversals. The car should not require surprising steering correction as speed rises. It should not feel as if the front or rear aero platform disappears at a repeatable ride-height event. In data, you would expect fewer unexplained speed-dependent balance changes, cleaner minimum-speed consistency in high-speed corners, and less straight-line penalty for a given downforce level. In visual inspection, you would expect exits for trapped wheel-well or under-front air to look intentional rather than accidental.
You can also calibrate by change isolation. If you add wheel-arch louvres, do not judge only engine or brake temperature. Watch straight speed, high-speed balance, and driver confidence. If you lower the front, do not judge only static splitter gap. Watch whether the car gains front load smoothly or begins to oscillate, scrape, or lose consistency. If you add rear wing angle, do not judge only rear grip. Watch whether underbody behavior improves because the rear wing is helping the diffuser, and also whether drag rises too much.
A common failure mode is chasing peak downforce while narrowing the operating window. A low front ride height, aggressive splitter, or strong front device may produce excellent load in one condition and then fall off when the car pitches lower. The felt symptom can be inconsistent front grip, oscillation, or a driver who cannot build confidence despite seeing high potential grip in some corners. The correction is not automatically raising the car or softening everything. The correction is to identify the dynamic condition where the flow stops behaving and set the platform so the car stays inside the useful range.
Another failure mode is sealing or venting the wrong thing. A closed-wheel car with trapped wheel-well pressure may create lift around the arches. Adding louvres or cutaways can help pressure escape, but only if the exit path improves the whole flow field. Poorly placed openings can dump high-energy or turbulent air into a region that another device needs. The correction is to map inlet, pressure source, and exit path before cutting bodywork.
A third failure mode is treating the front wheels as local drag only. On open-wheel cars, front wheel wakes influence downstream performance. You may reduce a small amount of local drag while making the sidepod, floor, rear body, or rear device worse. The correction is to trace the wake downstream and judge the car-level effect. This is why narrow central bodies and deflectors can matter as much as the wheel itself: they create routes for air to pass between or around the wheels.
A fourth failure mode is confusing duct success with aero success. A duct that cools well may still create drag or lift if it is careless. Brake, radiator, electronics, and induction air all have aerodynamic cost. The correction is to design and evaluate the whole duct, not just the inlet. The exit should serve a useful pressure region or at least avoid damaging a sensitive one.
A fifth failure mode is reading a rear diffuser without the rear wing. On many race cars, the rear wing and diffuser interact strongly. A rear-wing change can alter underbody static pressure well forward of the rear axle. The correction is to treat wing, diffuser, floor, and rear wake as linked. If a diffuser stalls or underperforms, the cause may be upstream feed, ride height, or rear-wing interaction, not just the diffuser geometry.
The recovery process is always the same: return to flow path, platform, and evidence. Flow path asks where the air comes from, what disturbs it, and where it exits. Platform asks what ride height, rake, pitch, roll, yaw, and speed do to that path. Evidence asks what the driver feels, what speed traces show, what pressure or tuft testing suggests, and whether the change helped the whole car rather than the part you were staring at.
For an intermediate driver, the most valuable habit is to stop separating aero from driving inputs. Braking pitch, steering angle, yaw, curb use, cresting, and throttle application change the aerodynamic problem. If you drive with unnecessary steering, you are not just abusing the front tires. If you smash over a crest in a car with sensitive ride height, you are not just testing suspension compliance. If you ask a low splitter to work while the nose is moving through a large pitch range, you are asking the airflow to stay attached through a changing duct. The driver is part of the aero environment.
This does not mean you should be afraid of aero. It means you should respect its conditions. Ground effect can be beneficial. Wheel-well exits can reduce lift. Deflectors can tidy wheel wakes. Rear wings can help diffusers. Ducts can use airflow energy with reduced losses. But every one of those benefits depends on where the air is before the device, how much energy it still has, how the car platform changes, and whether the air has a clean place to go afterward.
Carry this lesson into the next time you look at a car. Do not admire the largest device first. Look at the space between the car and the ground. Look at the tires as rotating disturbances. Look at the wheel wells as pressure volumes. Look at the floor as a duct whose shape changes with motion. Look at louvres and cutaways as exits, not styling. Look at the rear wing as a partner to the diffuser, not just a rear axle load tool. When you can explain how the road and wheels interfere with each flow path, you are no longer just naming aero parts. You are reading the car.
Worked example: open-wheel front wheels feeding the whole car
Picture an open-wheel single-seater. The front wheels sit in the airstream, rotate against the oncoming air at the top of the tire, touch the ground, steer, and operate at yaw. The source material is clear that this combination makes the flow over, around, and behind the wheels difficult to model or predict. It is also clear that front wheel wake matters because it can heavily influence the aerodynamic performance of everything downstream.
Your job in this example is to stop treating the front wheel as a part that only creates local drag. Start upstream of the sidepod or floor and ask what kind of air reaches it after the front wheel has disturbed the stream. If the car uses bargeboards, front-wing endplate flip-ups, or devices ahead of the wheels, read them as wake-management tools. They may also produce downforce, but their larger job is often to send air over, around, or between the wheels so the rest of the car receives a better flow condition.
The driving connection is steering discipline. If you add unnecessary steering angle, make mid-corner corrections, or hold a scrubbed front tire, you change the wake source. The time loss may show downstream as poorer aero efficiency, not merely as tire scrub at the front axle. The good version is a driver who releases excess steering as soon as the car accepts the line, keeps yaw tidy, and lets the aero devices behind the front axle see a repeatable flow condition lap after lap.
Worked example: closed-wheel front wheel wells, louvres, and splitter exits
Now picture a closed-wheel sports prototype or passenger-car-based race car with front wheel wells, a splitter, and bodywork over the wheels. The body shields the wheels from much of the outside airstream, so the open-wheel problem appears reduced. But air still enters the wheel wells from in front, underneath, and out to the sides. The rotating wheel can pump air in a semi-enclosed wheel well, and trapped pressure inside the wheel well can become a lift source when compared with the low static pressure over a curved wheel arch.
Louvres and side cutaways are the practical response in the corpus. Top louvres over sports prototype wheelarches help relieve the pressure difference between the wheel well and the air over the arch. Side cutaways behind the front wheels can help air leave the wheel well and also help air escape from under the front of the car. That matters because the splitter and diffuser are not isolated. The splitter can exploit air farther forward only if the used air has somewhere to exit without inflating the wrong pressure volume.
The engineering question is not whether vents look aggressive. The question is whether the front wheel-well system has a clean entry, a controlled pressure volume, and an exit that helps the rest of the car. If a change reduces front lift but adds drag or spoils side flow, the car may feel better in one corner phase and worse on the straight or at the rear. The good version is pressure relief that makes the high-speed balance more consistent while preserving the flow needed by the floor and rear devices.
Worked example: low ride height, front-wing stall, and porpoising
The pitch-sensitivity example is the clearest warning against assuming lower is always better. A front wing or near-ground device can gain downforce as it moves closer to the ground, but only inside its useful range. If it is run too close at low dynamic ride height, it can stall. Downforce then falls, the nose rises, flow reattaches, downforce returns, and the nose is pulled down again. The repeated cycle is porpoising.
For the driver, the important sensation is not the historical label. It is the loss of trust. The car seems to change its mind at speed. It may load the front, release it, then load it again, even though your hands and feet are steady. That is not a normal tire limit conversation. It is an aero-platform conversation.
The fix begins with recognizing the operating window. Static ride height is not enough. You need to know what the front device sees when speed builds, when the car pitches under braking, and when the surface compresses the suspension. The good version is a platform that keeps the device close enough to make useful load but not so close that it falls out of attachment or creates oscillation.
Common mistakes
Mistake one is lowering the car until it looks fast. Ground proximity can increase downforce for some devices, but the corpus also shows that too little clearance can reduce downforce or stall a front wing. Good looks like choosing ride height and rake for the dynamic condition, not for the paddock photo.
Mistake two is ignoring the underbody roughness. A rough underside full of protrusions and cavities creates slow, turbulent flow and a thick boundary layer that can merge into a wake reaching the ground. Good looks like asking whether the underbody can move fast, attached flow, not merely whether it has a low front lip or rear diffuser.
Mistake three is treating wheel wells as empty space. Closed-wheel bodywork hides much of the wheel, but air still enters the well and the rotating wheel can pump it. Good looks like providing intentional exits such as louvres or cutaways when the car and rules support them, then checking the car-level effect.
Mistake four is treating front wheel wake as somebody else’s problem. On open-wheel cars especially, the front wheel wake influences everything downstream. Good looks like minimizing unnecessary steering and understanding why deflectors, narrow body sections, and wake-management devices exist.
Mistake five is judging ducts only by cooling result. Cooling air has aerodynamic cost, and careless air diversion can add drag or lift. Good looks like evaluating inlet, restriction, and exit as one duct path.
Mistake six is tuning the rear wing as if the diffuser does not exist. The corpus supports a strong interaction between rear wing low pressure and diffuser performance, with rear-wing effects extending forward under the car. Good looks like testing rear-wing and underbody changes as linked balance tools.
Drill: wheel-and-ground interference walkdown
At your next event, do this drill once before the first session, once after a session with stable tire pressures, and once after any aero or ride-height change. It takes about ten minutes each time.
Step one: start at the front wheel. On an open-wheel car, trace where the wake can go. Identify what sends air over the wheel, around the wheel, between the wheels, or into the side of the car. On a closed-wheel car, identify how air enters the wheel well and where it exits.
Step two: move under the front of the car. Identify whether the splitter or front floor has an exit path for air. Look for protrusions, cavities, or blockage that would slow the underbody stream.
Step three: move along the floor. Ask how ride height and rake change the underbody cross-sectional area. Note whether braking pitch, acceleration pitch, or a crest could put the car into a very different attitude.
Step four: move to the rear. Identify whether the diffuser depends on rear-wing help. If the car has a rear wing, ask how its low-pressure field might assist the diffuser and underbody.
Step five: write one testable sentence before driving. Use this format: If this airflow path is the limiter, then I expect this felt symptom or data signature. Examples include high-speed front inconsistency after lowering the nose, straight-line drag increase after a cooling change, or improved high-speed balance after wheel-well pressure relief.
The success criterion is not being right every time. The success criterion is making one grounded prediction, changing only one relevant variable when possible, and comparing the driver feel or data against the prediction. After three event days, you should be faster at identifying whether a handling complaint belongs to tires, mechanical platform, or wheel-and-ground aero interference.
When this principle breaks down
This principle does not break down in the sense that wheels and ground stop mattering. It breaks down when you try to turn it into a single universal setup rule. Lower is not always better, but higher is not automatically better. Wheel-well exits can help, but cutting holes without understanding the pressure path can hurt. Rear wings can help diffusers, but more wing can also add drag or shift balance. Deflectors can tidy wheel wake, but their value depends on what they do to the whole downstream flow.
The reliable rule is conditional: respect the local device, the upstream disturbance, the downstream exit, and the dynamic platform at the same time. If you cannot explain those four pieces, you are guessing.
Author Review
No quiz questions are attached to this lesson.
Sources
| # | Document | Chunk | Pages | Score | Collection |
|---|---|---|---|---|---|
| 1 | Competition Car Aerodynamics 3rd Edition McBeath Simon | a1b96fa7-829e-cf1e-a3d5-42bc39e51de0 | 227 | 1 | uio_books_raw_v1 |
| 2 | Competition Car Aerodynamics 3rd Edition McBeath Simon | 8a9b8241-33e6-a096-ec3e-ae69885b0483 | 282 | 1 | uio_books_raw_v1 |
| 3 | Competition Car Aerodynamics 3rd Edition McBeath Simon | 52658ce3-2ca2-2263-063d-df42929ed14e | 283 | 1 | uio_books_raw_v1 |
| 4 | Competition Car Aerodynamics 3rd Edition McBeath Simon | e026c4ea-8039-2e4c-7120-43aec22c96d6 | 284 | 1 | uio_books_raw_v1 |
| 5 | Competition Car Aerodynamics 3rd Edition McBeath Simon | d3dc9858-9a3f-281f-0bec-c2c8d072705a | 193 | 1 | uio_books_raw_v1 |
| 6 | Competition Car Aerodynamics 3rd Edition McBeath Simon | 532d0edc-f111-725e-3ac8-143bb8ba73c4 | 250 | 1 | uio_books_raw_v1 |
| 7 | Competition Car Aerodynamics 3rd Edition McBeath Simon | abaca23e-4ddb-9839-1862-fcf9c485584e | 251 | 1 | uio_books_raw_v1 |
| 8 | Road vehicle aerodynamics Scibor-Rylski A. J Sykes D. M | 374da5e1-c98d-f20b-32e5-173ccd9fa3ad | 45 | 1 | uio_books_raw_v1 |