Originally posted by BigBoss:
Hi All,
I'm trying to reason through a radiator sizing script, based on BeaverGuy's prescriptions. Say I know the average heat rejection that I would like to dissipate, as well as all the temps, the mass flow rates of the coolant and air, heat capacity.
1.) Ch & Cc; find Cmax & Cmin of the 2; find Cr
2.) Find Qmax
3.) Find effectiveness; Qneeded/Qmax
4.) Find NTU based on Cr & e
5.) Guess a U
6.) NTU = UA/Cmin ; re-arrange so Aguessed = NTU*Cmin/Uguessed
Q
oes U & A combination reject enough heat?
1b.) calculate Cc & Ch based on guessed A
2b.) calculate Cr, NTU, e
3b.) If we know Cmin from 1b.), we can find the new Qmax
4b.) From all the above, we can find the new, actual Q rejected
5b.) Check: Does new Q act ~ target Q act? If so, A & U is correct; otherwise iterate.