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Old 08-15-2017, 01:06 AM   #136 (permalink)
t vago
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Quote:
Originally Posted by josemapiro View Post
Hi t vago

I wanted to do some coastdown testing but I need your help.
First as this topic is very technical the translation does not always represent what it is actually transmitting to me, that's why I asked if it's possible that I try to explain myself in the less technical way, maybe this way the translation will be easier.

For the coastdown test it takes 3 values.
1st vehicle frontal area I already have.
2nd Density of the air, this value as you get it, there is some site where you can see this value or it is through calculations. I have tried several sites of Weather but do not have this value.
3rd period between samples, what is the value that you think is most appropriate for these tests.

What is the procedure for getting the results, what kind of road is the most suitable for the test and what values can I get, just to get an idea if I'm not doing something wrong.

Thanks
José Rodrigues
The second parameter, air density, can be found from converting barometric pressure and outside air temperature, to density. Link here -> How to Calculate Air Density - Fly Me to the Moon

The third, period between samples, is a good guess. I would pick once every 5 seconds.

You'll want to find a nice, smooth, flat section of road. No bumps, dips, humps, potholes, inclines, or anything else that might interfere with the coastdown itself.

Keep in mind that coastdown doesn't work yet because it isn't fully coded. I have yet to program a matrix equation solver. I also have to figure out how I am going to account for vehicle lift at higher speeds.
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