Air flow & heatsink- convert cubic feet per minute to li

[ballimo]

Air flow & heatsink

Hello,

I am using a TO220 heetsink for a power resistor, the heatsink datasheet include a graph of the thermal resistance versus the air flow velocity in linear feet per minute.
the PCB will be inclosed in a metal enclosure, the Fans in this enclosure produce produce 116 cubic feet per minute.

My question is how can I convert the cubic feet per minute to linear?, because I want to know the exact thermal resistance of the heatsink.

thanks in advance,

Ballimo

 

[eem2am]

Air flow & heatsink

you calculate volume of your enclosure.

you calcualte how long it takes your fan to "flush out" one enclosure's worth of air.

find the longest dimension of your enclosure.

This length divided by the time of "fludsh" above is the linear airflow u wanting