HomePortalFAQSearchRegisterMemberlistUsergroupsLog in

Share | 
 

 Smart brains and/or internet surfers needed

View previous topic View next topic Go down 
AuthorMessage
Xeos
Officer
Officer
avatar

Posts : 880
Join date : 2007-12-10

PostSubject: Smart brains and/or internet surfers needed   Sat Jul 26, 2008 6:32 pm

I have this problem I am hoping I can pick this communities brain for an answer. I have a fan that I need to run at 3000rpm which is belt driven, and the belt is driven by a hydraulic motor, I have the hydraulic motor powered by a hydraulic pump direct driven off of the front of the crank on a truck motor. Currently I got it to run at 1750rpm with 35HP and 2200psi running the pump off the front of the motor, I fell short. What I am looking for is relationship equations for my variables so that I can correctly tweak the system to work properly, without shooting in the dark and buying a whole bunch of unnecessary pumps/motors. The relationship equations that I need include relations for the following.

Work(HP), Pressure(PSI), Volume(GPM)

and

Work(HP), RPM(Fan)


an example of what I am looking for but is obviously wrong is
Work=Pressure*Volume

I know there are probably some constants involved as well. Also do you think the relationship between Work applied to the fan is a linear relationship or parabolic? Essentially I need to get the HP from the motor to the fan, but in order to do so I have to use a hydraulic and belt system.

*cough Tak Almagest cough*
Back to top Go down
View user profile
Tak

avatar

Posts : 404
Join date : 2008-01-07

PostSubject: Re: Smart brains and/or internet surfers needed   Sat Jul 26, 2008 10:30 pm

I think it should be linear, but there are constants dependent upon the efficiency of the motor and the pump.
Back to top Go down
View user profile
Xeos
Officer
Officer
avatar

Posts : 880
Join date : 2007-12-10

PostSubject: Re: Smart brains and/or internet surfers needed   Sun Jul 27, 2008 12:10 am

Really it is linear? What you are saying then that if 35HP runs the fan at 1750rpm, 70HP should run it at 3500rpm ? I was under the impression that it took more work to increase the fans rpms, from 2000-2500 than it did from 1500-2000.

Do you know the generic equations that I can plug my numbers into?
Back to top Go down
View user profile
Almagest

avatar

Posts : 113
Join date : 2008-01-11
Age : 35
Location : Physics!

PostSubject: Re: Smart brains and/or internet surfers needed   Sun Jul 27, 2008 1:07 am

Just going from physics equations, HP should relate to RPM in a quadratic fashion, i.e. you increase the power by 4 to increase RPM by 2.

YOU SHOULD KNOW THIS, TAK.
Back to top Go down
View user profile
Xeos
Officer
Officer
avatar

Posts : 880
Join date : 2007-12-10

PostSubject: Re: Smart brains and/or internet surfers needed   Sun Jul 27, 2008 3:06 am

Thank you Almagest, that gives me a good start in the right direction. I had a gut feeling that it wasn't linear, we ALMOST bought went the routeof doubling the HP to double the RPM. With what you have told me it will be more likely to have to quadruple the HP to double the RPM, no exactly but a generic rule of thumb.
Back to top Go down
View user profile
Ichaerus
Officer
Officer
avatar

Posts : 784
Join date : 2008-04-05
Age : 29
Location : Under a Black Hat.

PostSubject: Re: Smart brains and/or internet surfers needed   Sun Jul 27, 2008 4:59 am

42.
Back to top Go down
View user profile
Necis
Officer
Officer
avatar

Posts : 466
Join date : 2007-12-12

PostSubject: Re: Smart brains and/or internet surfers needed   Sun Jul 27, 2008 7:06 am

Ah the answer to life the universe and everything.

_________________
Ah, women. They make the highs higher and the lows more frequent. - Friedrich Nietzsche
Back to top Go down
View user profile
Sponsored content




PostSubject: Re: Smart brains and/or internet surfers needed   

Back to top Go down
 
Smart brains and/or internet surfers needed
View previous topic View next topic Back to top 
Page 1 of 1
 Similar topics
-
» FREE Gift for Internet Safety Agents!
» Tau Smart Missile System
» My internet disconnects everytime someone calls on my phone.
» Never take ONO as your internet provider if you go to spain...
» HELP!!! Chaos Space Marine models needed for Wargamescon Mirror Match List!!!

Permissions in this forum:You cannot reply to topics in this forum
 :: Public Topics :: Off-Topic-
Jump to: