How to calculate Vehicle Aerodynamics

January 7, 2023
Lamborghini Huracan STO
January 13, 2023

The study of air movement and its interactions with solid things is known as aerodynamics. Aerodynamics, in the context of automobiles, is concerned with the design and optimization of the shape and other aspects of the vehicle to reduce drag and increase performance.

The performance, stability, and fuel efficiency of a vehicle are significantly influenced by its aerodynamics. The vehicle’s speed, acceleration, and fuel efficiency can be increased by giving it a streamlined shape and other elements that reduce drag. Additionally, aerodynamics can affect a vehicle’s handling and stability, particularly at high speeds.

The aerodynamics of a vehicle can be improved through a variety of methods, such as computer simulation, on-road testing, and wind tunnel testing. These methods are used by engineers to examine a vehicle’s aerodynamic features and alter the design to enhance performance.

In the previous blog we learn about What is aerodynamic of vehicle and how can we test it. In this blog we will see how to calculate some important terminologies like :

• Aerodynamic Coefficient
• Drag Force
• Down Force
• Lift Force
• Streamlining
• Turbulence
• Thrust force

Steps to calculate Aerodynamic Coefficient:

The aerodynamic coefficient of a car is a measure of the drag that the vehicle experiences as it moves through the air. It is often expressed as a decimal value, and a lower coefficient indicates a more aerodynamic vehicle. Here is a general process for calculating the aerodynamic coefficient of a car:

• Determine the velocity of the car: The first step in calculating the aerodynamic coefficient of a car is to determine the velocity of the car. This will be a key factor in determining the amount of drag that the car experiences as it moves through the air.
• Measure the drag and lift forces experienced by the car: The next step is to measure the drag and lift forces experienced by the car. These forces can be measured using sensors or other instruments, and they will be used to calculate the aerodynamic coefficients of the car.
• Calculate the density of the air: The density of the air is another important factor in determining the aerodynamic coefficient of the car. The density of the air is affected by factors such as temperature, humidity, and altitude.
• Calculate the surface area of the car: The surface area of the car is also an important factor in calculating the aerodynamic coefficient. The larger the surface area of the car, the more drag and lift will be generated by the airflow over the surface.
• Use a formula to calculate the aerodynamic coefficient: Once all of these factors have been determined, they can be used in a formula to calculate the aerodynamic coefficient of the car. The aerodynamic coefficient is often expressed as a decimal value, and it can be calculated using the following formula: Aerodynamic coefficient = (Drag force + Lift force) / (1/2 x air density x velocity^2 x surface area).
• Repeat the process at different velocities: To get a more accurate measurement of the aerodynamic coefficient, it is often necessary to repeat the process at different velocities. This will allow you to get a more complete picture of the aerodynamic characteristics of the car and help you to optimize its performance.

Steps to calculate Drag Force:

Drag is the resistance that the air exerts on a vehicle as it moves through it. It is caused by the interaction between the air and the surface of the vehicle, and it can have a significant impact on the vehicle’s performance. Here is a general process for calculating the drag of a vehicle:

• Determine the velocity of the vehicle: The first step in calculating the drag of a vehicle is to determine the velocity of the vehicle. This will be a key factor in determining the amount of drag that is experienced by the vehicle.
• Measure the aerodynamic coefficients of the vehicle: The next step is to measure the aerodynamic coefficients of the vehicle. These coefficients are used to describe the aerodynamic characteristics of the vehicle and include factors such as the drag coefficient and the lift coefficient.
• Calculate the density of the air: The density of the air is another important factor in determining the amount of drag that is experienced by the vehicle. The density of the air is affected by factors such as temperature, humidity, and altitude.
• Calculate the surface area of the vehicle: The surface area of the vehicle is also an important factor in calculating drag. The larger the surface area of the vehicle, the more drag will be generated by the airflow over the surface.
• Use a formula to calculate the drag: Once all of these factors have been determined, they can be used in a formula to calculate the drag that is experienced by the vehicle. A common formula for calculating drag is: Drag = (1/2) x air density x velocity^2 x surface area x coefficient of drag.

Steps to calculate downforce:

Downforce is a force that is generated by the flow of air over the surface of a vehicle, which pushes the vehicle down towards the ground. It is the opposite of lift and can improve the stability and handling of a vehicle at high speeds. Here is a general process for calculating downforce in a vehicle:

• Determine the velocity of the vehicle: The first step in calculating downforce is to determine the velocity of the vehicle. This will be a key factor in determining the amount of downforce that is generated by the airflow over the surface of the vehicle.
• Measure the aerodynamic coefficients of the vehicle: The next step is to measure the aerodynamic coefficients of the vehicle. These coefficients are used to describe the aerodynamic characteristics of the vehicle and include factors such as the drag coefficient and the lift coefficient.
• Calculate the density of the air: The density of the air is another important factor in determining the amount of downforce that is generated by the airflow over the surface of the vehicle. The density of the air is affected by factors such as temperature, humidity, and altitude.
• Calculate the surface area of the vehicle: The surface area of the vehicle is also an important factor in calculating downforce. The larger the surface area of the vehicle, the more downforce will be generated by the airflow over the surface.
• Use a formula to calculate the downforce: Once all of these factors have been determined, they can be used in a formula to calculate the downforce that is generated by the airflow over the surface of the vehicle. A common formula for calculating downforce is: Downforce = (1/2) x air density x velocity^2 x surface area x coefficient of lift.

Steps to calculate Lift Force:

Lift force is the upward force that is experienced by a vehicle as it moves through the air. It is caused by the interaction between the air and the surface of the vehicle, and it can have a significant impact on the performance and stability of the vehicle. Here is a general process for calculating the lift force in cars:

• Determine the velocity of the car: The first step in calculating the lift force of a car is to determine the velocity of the car. This will be a key factor in determining the amount of lift force that is experienced by the car.
• Measure the lift coefficient of the car: The next step is to measure the lift coefficient of the car. The lift coefficient is a measure of the lift force experienced by the car and is affected by factors such as the shape and size of the car.
• Calculate the density of the air: The density of the air is another important factor in determining the lift force of the car. The density of the air is affected by factors such as temperature, humidity, and altitude.
• Calculate the surface area of the car: The surface area of the car is also an important factor in calculating the lift force. The larger the surface area of the car, the more lift force will be generated by the airflow over the surface.
• Use a formula to calculate the lift force: Once all of these factors have been determined, they can be used in a formula to calculate the lift force of the car. A common formula for calculating lift force is: Lift force = (1/2) x air density x velocity^2 x surface area x lift coefficient.

Steps to calculate streamlining of cars:

Streamlining is the process of designing a vehicle to minimize drag and maximize performance. Here is a general process for calculating the streamlining of a vehicle:

• Measure the drag coefficient: The first step in calculating the streamlining of a vehicle is to measure its drag coefficient. The drag coefficient is a measure of the drag experienced by the vehicle as it moves through the air and is affected by factors such as the shape and size of the vehicle.
• Determine the velocity of the vehicle: The next step is to determine the velocity of the vehicle. This will be a key factor in determining the amount of drag that the vehicle experiences as it moves through the air.
• Calculate the density of the air: The density of the air is another important factor in determining the streamlining of the vehicle. The density of the air is affected by factors such as temperature, humidity, and altitude.
• Calculate the surface area of the vehicle: The surface area of the vehicle is also an important factor in calculating its streamlining. The larger the surface area of the vehicle, the more drag will be generated by the airflow over the surface.
• Use a formula to calculate the streamlining: Once all of these factors have been determined, they can be used in a formula to calculate the streamlining of the vehicle. A common formula for calculating streamlining is: Streamlining = 1 / (drag coefficient x (1/2) x air density x velocity^2 x surface area).

Steps to calculate Turbulence:

Turbulence is the irregular movement of air that can occur as it flows over the surface of a vehicle. It can have a significant impact on the aerodynamics of the vehicle, affecting factors such as drag and lift. Here is a general process for calculating turbulence in vehicle aerodynamics:

• Measure the turbulence intensity: The first step in calculating turbulence in vehicle aerodynamics is to measure the turbulence intensity. This can be done using sensors or other instruments that are placed on or near the surface of the vehicle. The turbulence intensity is a measure of the strength of the turbulent airflow and is often expressed as a decimal value.
• Determine the velocity of the airflow: The next step is to determine the velocity of the airflow over the surface of the vehicle. This will be a key factor in determining the amount of turbulence that is experienced by the vehicle.
• Calculate the length scale of the turbulence: The length scale of the turbulence is another important factor in calculating turbulence in vehicle aerodynamics. It is a measure of the size of the turbulent eddies and is often expressed as a length value.
• Use a formula to calculate the turbulence: Once all of these factors have been determined, they can be used in a formula to calculate the turbulence in vehicle aerodynamics. A common formula for calculating turbulence is: Turbulence = turbulence intensity x velocity / length scale.

Steps to calculate thrust forces:

Thrust force is the forward force that is experienced by a vehicle as it moves through the air. It is caused by the interaction between the air and the surface of the vehicle, and it can have a significant impact on the performance and stability of the vehicle. Here is a general process for calculating the thrust force of a vehicle:

• Determine the velocity of the vehicle: The first step in calculating the thrust force of a vehicle is to determine its velocity. This will be a key factor in determining the amount of thrust force that is experienced by the vehicle.
• Measure the drag coefficient of the vehicle: The next step is to measure the drag coefficient of the vehicle. The drag coefficient is a measure of the drag experienced by the vehicle as it moves through the air and is affected by factors such as the shape and size of the vehicle.
• Calculate the density of the air: The density of the air is another important factor in determining the thrust force of the vehicle. The density of the air is affected by factors such as temperature, humidity, and altitude.
• Calculate the surface area of the vehicle: The surface area of the vehicle is also an important factor in calculating its thrust force. The larger the surface area of the vehicle, the more thrust force will be generated by the airflow over the surface.
• Use a formula to calculate the thrust force: Once all of these factors have been determined, they can be used in a formula to calculate the thrust force of the vehicle. A common formula for calculating thrust force is: Thrust force = (1/2) x air density x velocity^2 x surface area x drag coefficient.

Why calculating aerodynamics of vehicle is important:

There are several reasons why we need to calculate all these factors and make vehicle aerodynamic some of them are as follows:

• Improved performance: By optimizing the aerodynamics of a vehicle, it is possible to improve its performance in terms of speed, acceleration, and fuel efficiency. This can be especially important in motorsports, where aerodynamics can play a key role in determining the competitiveness of a vehicle.
• Enhanced stability and handling: Aerodynamics can also have a significant impact on the stability and handling of a vehicle. By designing the vehicle to generate a certain amount of downforce, it is possible to improve its stability and handling at high speeds.
• Reduced fuel consumption: Aerodynamics can also play a role in reducing the fuel consumption of a vehicle. By reducing the drag experienced by the vehicle, it is possible to reduce the amount of energy that is required to propel the vehicle, which can improve its fuel efficiency.
• Enhanced safety: Aerodynamics can also have an impact on the safety of a vehicle. By designing the vehicle to generate a certain amount of downforce, it is possible to improve its stability and handling, which can help to reduce the risk of accidents.