It's a system duct design question.
Q = m(dot)Cp(delta)T
i have to choose an axial fan to provide cooling, how do i find the Q?
i have (delta)T, Cp.
2006-07-23 01:31:33 · 3 answers · asked by tanyl78 1 in Science & Mathematics ➔ Engineering
I might be missing out because your info is a bit vague, but this is what I'd think:
-Q would be the amount of heat that has to be led away.
for example if you need to cool a power transistor producing 60W of heat, Q would be 60 (in duct design calculations this is allmost allways a given parameter, you allways need a power to be evacuated)
-you have Cp
-you have deltaT which is the increase in temperature of the air due to evacuation of the heat.
then you can calculate the massflow that is needed to evacuate the excess heat, and this lets you choose the right fan.
Either Q or M should be given to solve the equation, (if not you need extra info to put up a scheme), but without other given parameters you can't work this out..
2006-07-23 01:59:45 · answer #1 · answered by III 3 · 2⤊ 0⤋
You have to be given Q, the heat transfer rate. Recheck the problem to see if it's in there. Then you can figure the mass flow rate Mdot from the equation you gave (where Cp is the heat coefficient of air and deltaT is the air temperature change). Then you look up the density of air at whatever temperature it will be at when it passes the fan, and the required fan capacity (volume/time) is Mdot/density.
2006-07-23 09:12:34 · answer #2 · answered by kirchwey 7 · 0⤊ 0⤋
If this is the only equation you have, you have to know all but one variable in order to solve the equation.
2006-07-23 08:57:45 · answer #3 · answered by Nick 4 · 0⤊ 0⤋