STU666V
Active Member
Hi,
Was thinking in making or buying a front splitter that works!!
Any body have an ideas?
This tutorial will explain how an external flow interacts with a car to affect its dynamics. The drawing below shows a representation of the path of air moving around a car (or more correctly, the path of air as the car moves through it).
At the front of the car, the oncoming air goes through a process of stagnation, slowing down and increasing in pressure. This is represented by the shaded area at the front of the car. The airflow parts and some goes over the car while some goes below it. The air moving over the car follows the hood, but when it reaches the sharp direction change at the base of the windshield, it stagnates again. It then continues up over the roof to the rear windshield. At this point, the momentum of the air and the friction of the car's surface are usually not enough to keep the airflow attached, and flow separates over the rear windshield. This phenomenon creates an area of low pressure above the rear windscreen and over the trunk. This effect further continues to the rear of the car as the airflow is subjected to another drastic direction change when the trunk drops off to the rear bumper.
The flow that goes beneath the car is subjected to many obstacles along its path. Underneath the car, the air strikes the oil pan, steering rack, and transmission, causing it to stagnate. It runs into the tires, also inducing stagnation. As it continues along the length of the car, it further runs into the driveshaft, exhaust, rear end, and gas tank, all of which cause the flow to stagnate. The air finally exits at the rear of the car into the low pressure wake at the rear bumper.
The stagnation zone at the front of the car creates an area of high pressure, while the flow separation at the rear creates an area of low pressure. This pressure differential creates a force pushing opposite the car's direction of travel, called drag. Similarly, the stagnation below the car coupled with the separation above the trunk creates a net upward force, called lift. Both of these forces increase with vehicle speed - as the car goes faster, the effects increase. In the world of automotive performance, both drag and lift are bad. Drag holds the car back, limiting both acceleration and top speed. Lift reduces the weight of the car on the tires, lessening steering response, stability, and overall grip.
To combat the effect of these forces, several devices have been developed over the years.
Spoilers
A spoiler is simply a device that slows and collects air, causing it to stagnate. The most common spoilers are placed at the rear of the car, over the trunk, as shown below.
The spoiler creates an area of high pressure to replace the usual low pressure over the trunk. This helps reduce the pressure differential between the bottom and top of the car, reducing lift. The only drawback to spoilers is that they usually increase drag. Because all of the air collects in front of the spoiler, there is very little behind it. The spoiler itself contributes to the pressure differential between the front and back of the car, increasing drag. However, in rare cases, the increased pressure drop behind the spoiler can help pull air from beneath the car to fill in the void at the rear bumper, causing a net decrease in drag, but this is a rare circumstance.
Was thinking in making or buying a front splitter that works!!
Any body have an ideas?
This tutorial will explain how an external flow interacts with a car to affect its dynamics. The drawing below shows a representation of the path of air moving around a car (or more correctly, the path of air as the car moves through it).
At the front of the car, the oncoming air goes through a process of stagnation, slowing down and increasing in pressure. This is represented by the shaded area at the front of the car. The airflow parts and some goes over the car while some goes below it. The air moving over the car follows the hood, but when it reaches the sharp direction change at the base of the windshield, it stagnates again. It then continues up over the roof to the rear windshield. At this point, the momentum of the air and the friction of the car's surface are usually not enough to keep the airflow attached, and flow separates over the rear windshield. This phenomenon creates an area of low pressure above the rear windscreen and over the trunk. This effect further continues to the rear of the car as the airflow is subjected to another drastic direction change when the trunk drops off to the rear bumper.
The flow that goes beneath the car is subjected to many obstacles along its path. Underneath the car, the air strikes the oil pan, steering rack, and transmission, causing it to stagnate. It runs into the tires, also inducing stagnation. As it continues along the length of the car, it further runs into the driveshaft, exhaust, rear end, and gas tank, all of which cause the flow to stagnate. The air finally exits at the rear of the car into the low pressure wake at the rear bumper.
The stagnation zone at the front of the car creates an area of high pressure, while the flow separation at the rear creates an area of low pressure. This pressure differential creates a force pushing opposite the car's direction of travel, called drag. Similarly, the stagnation below the car coupled with the separation above the trunk creates a net upward force, called lift. Both of these forces increase with vehicle speed - as the car goes faster, the effects increase. In the world of automotive performance, both drag and lift are bad. Drag holds the car back, limiting both acceleration and top speed. Lift reduces the weight of the car on the tires, lessening steering response, stability, and overall grip.
To combat the effect of these forces, several devices have been developed over the years.
Spoilers
A spoiler is simply a device that slows and collects air, causing it to stagnate. The most common spoilers are placed at the rear of the car, over the trunk, as shown below.
The spoiler creates an area of high pressure to replace the usual low pressure over the trunk. This helps reduce the pressure differential between the bottom and top of the car, reducing lift. The only drawback to spoilers is that they usually increase drag. Because all of the air collects in front of the spoiler, there is very little behind it. The spoiler itself contributes to the pressure differential between the front and back of the car, increasing drag. However, in rare cases, the increased pressure drop behind the spoiler can help pull air from beneath the car to fill in the void at the rear bumper, causing a net decrease in drag, but this is a rare circumstance.
