Haf
Mechanical
- Nov 6, 2001
- 176
I once came across a useful equation for estimating the convection coefficient for calculating convective heat transfer from the combustion gases to the surroundings (i.e., piston and bore) in a diesel engine. The equation was of the form:
h = C*b^(m-1)*P^m*w^m*T^(0.75-1.62*m)
where
h is the convection coefficient
b is the bore diameter
P is pressure
w is the mean gas velocity (estimated as mean piston velocity)
T is temperature
C and m are constants
The reference also claimed that the overall heat transfer was 65% convection, 35% radiation.
I have used this equation and relation several times over the last two years with relatively good success. The embarassing thing is I can't find or remember where this equation and relation came from. Is anyone familiar with the above equation, and if so, could you provide the reference it comes from?
Thanks,
Haf
h = C*b^(m-1)*P^m*w^m*T^(0.75-1.62*m)
where
h is the convection coefficient
b is the bore diameter
P is pressure
w is the mean gas velocity (estimated as mean piston velocity)
T is temperature
C and m are constants
The reference also claimed that the overall heat transfer was 65% convection, 35% radiation.
I have used this equation and relation several times over the last two years with relatively good success. The embarassing thing is I can't find or remember where this equation and relation came from. Is anyone familiar with the above equation, and if so, could you provide the reference it comes from?
Thanks,
Haf