Aerodynamics Question

blacklionboy

Just doing a project concerning aerodynamics and was doing some research on the basic principals.

Sorry if this is a stupid question.

What is difference between "Drag" and "drag coefficent"?

I keep hearing these two terms and found that the internet gives no simple answer. Thanks!

judas101

drag is a force which is measured in newtons.

drag coefficient is a dimensionless quantity which indicates the drag characteristics of a body.

higher drag coefficients indicate higher levels of drag forces, i.e. a sphere will have a higher drag coefficient than an aerofoil of the same frontal area.


an interesting point to note is that for wings, drag coefficient is usually expressd per meter which of course is not dimenionless. this is standard in industry however as it allows for easy comparison bettween various configurations.


all the above is also true for lift and coefficient of lift.

blacklionboy

any formula's for drag coefficentcy that could be used for this sort of car project ---> www.f1inschools.ie

thanks!

judas101

formula for drag coefficient is always drag force divided by (0.5 x density X velocity x area)

this holds for all applications.

for a race car project youd also need to look into levels of downforce (negative lift)

the exact same forces are at work as you cant create downforce without inherently creating drag.

i did my thesis on all this stuff so keep the questions coming if you need to.

blacklionboy

judas101 wrote: »

formula for drag coefficient is always drag force divided by (0.5 x density X velocity x area)

this holds for all applications.

for a race car project youd also need to look into levels of downforce (negative lift)

the exact same forces are at work as you cant create downforce without inherently creating drag.

i did my thesis on all this stuff so keep the questions coming if you need to.

thanks mate. might have questions in near future!