Car/Race Car aerodynamics Flashcards
What are the main aims of car aerodynamics?
Reduced drag Prevent undesired lift forces Reduce wing and emmision noise Preventing casues of instability Improve handling characteristics Improve comfort
What makes car aerodynamics different to an aircraft?
A car is a bluff body rather than a streamlined one
Car aerodynamics dominated by pressure drag due to unavoidable seperation
Car aerodynamics takes passive role as functionality and confort are more important
Car aerodynamics normally tested in wing tunnels (experimental)
What are the three different flow fields in car aerodynamics?
Flow around the vehicle body
Flow around/through vehicles components (engine, wheels)
Internal flow around passenger cabin
Aerodynamic drag increases with the…?
Square of velocity
What are the three major drag contributors in a car?
Upper body (roughly 50%) Under body (roughly 25%) Wheels and arches (roughly 25%)
What angle of rear screen wake produces the minimum drag?
10 degrees. Anymore and vortex drag drastically increases due to seperation.
What are the neagatives of increasing front screen rake angle (shallower angle) ?
While it can reduce seperation it also increases solar heating and internal reflections which affect the driver safety/comfort.
What is the component used on the underbody to reduce drag?
A diffuser
Whats the difference between priorities in a normal car and a racing car?
Normal car aims to reduce drag and increase stability.
Racing car aims to design for downforce where flow goes around open wheels, also air cooling and minimisation of drag.
Whats the difference between passive and active aerodynamics?
Active aerodynamics attempt to manipulate the flow to benefit the vehicle rather than allow the vehicle to travel through passively.
Examples of passive modifications include?
Spoiler No side mirrors Diffuser Flat underbody Side skirts Wheel deflector
Examples of active modifications include?
Grill Shutter Adjustable front/rear spoiler Aero rims Extendable diffuser Extended roof spoiler
What aspects of racing cars produce the large downforce?
Inverted front wing
Flat underbody with diffuser work with rear wing to produce downforce.
How does skirting help on a race car?
Skirting maintains the lower pressure of the underbody and so maintains the suction and downforce.
What is the most complicated part of the race car to an aerdynamisist?
The four large wheels
