On 29 Jul 2005 06:12:00 -0700, "smitha4u"
wrote:

Hello all
I am new to this group and found some interesting discussions iin this
so i thought i could get soome help from you.
My question may be sort of silly but i am coming out.
Can any one explain what are system curves for an electrical fan and
what are the fan curves. what is the difference between those.
If we are given an electrical with motor specification how can we draw
system curves and fan curves to defiine a operating point for the fan.
what data should i need to collect for that.
I have the el.motor spec as 2Kw, 200rpm variable speed DC motor. I was
given a question in the class that " if you are asked to draw sytem
curves and fan curves and find the operating point of the fan with the
given motor spec. assume a cooling scenario in the car and think of a
radiator fan to be designed" so this is my actual queest.
I appreciate if any one could help me in understanding this in detail
or help me with some websites where i could get better info
Regards
Smitha

See
http://tinyurl.com/7b9lz

Buffalo Forge used to publish a very good book entitled "Fan
Engineering", copyright 1970 by Buffalo Forge. No ISBN number,
apparantly only available from Buffalo Forge. 729 pages. It
thoroughly treats fan curves and related issues.

Fan curves show the relationship between pressure, flow, speed and
power *for a given fan*. Designing a fan to produce a given
behavior is a very complex matter. You would also need to know (or
define, or measure) the flow vs pressure behavior of your radiator.