|
[Sponsors] |
![]() |
![]() |
#1 |
Guest
Posts: n/a
|
Hello everybody! I want to calculate the convective heat transfer coefficient of a cylinder with Fluent. - diameter of the cylinder : d = 0,1524 m - temperature of the cylinder: Tcyl = 273,15 K - temperature of the airflow: Ta = 268,30 K - air velocity : u = 90 m/s - air pressure : p = 100 000 Pa - y+ : between 20 and 50
at "XY Plot" - "Wall Fluxes" - "surface heat coefficient" I receive a value hc=90 W/m²K at the stagnation point. In an article about NASAs LEWICE, they maintain a value of hc=170 W/m²K. In another article, there is a equation für the coefficient for a cylinder: hc = thermal conductivity * Nusselt number/diameter with Nusselt Number = 1,14 * (Prandtl^0,4)*(Reynold^0,5); there you get a value hc = 165 W/m²K Do I have to consider something tricky with fluent because my value is pretty low? |
|
![]() |
![]() |
![]() |
#2 |
Guest
Posts: n/a
|
Heat transfer is very sensitive to the y+ value used. You are probably going to need to reduce your y+ down substantially to get a good value (possibly down as low as 0.1-0.2). No trickery involved, just getting good resolution of the temperature gradient.
|
|
![]() |
![]() |
![]() |
#3 |
Guest
Posts: n/a
|
you should check the reference value for temperature!
|
|
![]() |
![]() |
![]() |
#4 |
Guest
Posts: n/a
|
Dear sir,
I want to calculate the convective heat transfer coefficient of a cylinder casing with temperature 200 deg c, tempearature of air flow outside the casing will be 45 deg c with humidity 95%, please assist me in this regard to proceed with calculation by providing reference material or sample calculations. regards, p k saloni |
|
![]() |
![]() |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
Heat transfer coefficient - what is waht | Stan | FLUENT | 24 | August 31, 2020 07:41 |
Water subcooled boiling | Attesz | CFX | 7 | January 5, 2013 04:32 |
Constant velocity of the material | Sas | CFX | 15 | July 13, 2010 09:56 |
Convective / Conductive Heat Transfer in Hypersonic flows | enigma | Main CFD Forum | 2 | November 1, 2009 23:53 |
Convective Heat Transfer - Heat Exchanger | Mark | CFX | 6 | November 15, 2004 16:55 |