- #1
Kozy
- 141
- 7
I am building a mathematical model of a piston engine which calculates the pressure and temperature of the cylinder gas every 1° of crank angle.
I'm having some difficulty with the heat transfer to and from the cylinder wall (to when the Tg > Tw and from when Tg < Tw).
I found the heat transfer equation on EngineeringToolbox.com
q = 2 π k (ti - to) / ln(ro / ri) (1)
where
q = heat transferred per unit time per unit length of cylinder or pipe (W/m, Btu/hr ft)
k = thermal conductivity of the material (W/m.K or W/m oC, Btu/(hr oF ft2/ft))
to = temperature outside pipe or cylinder (K or oC, oF)
ti = temperature inside pipe or cylinder (K or oC, oF)
ln = the natural logarithm
ro = cylinder or pipe outside radius (m, ft)
ri = cylinder or pipe inside radius(m, ft)
http://www.engineeringtoolbox.com/conductive-heat-loss-cylinder-pipe-d_1487.html
Which gives me an heat loss in W. How do I convert the loss in W to a reduction in temperature in °K?
I'm having some difficulty with the heat transfer to and from the cylinder wall (to when the Tg > Tw and from when Tg < Tw).
I found the heat transfer equation on EngineeringToolbox.com
q = 2 π k (ti - to) / ln(ro / ri) (1)
where
q = heat transferred per unit time per unit length of cylinder or pipe (W/m, Btu/hr ft)
k = thermal conductivity of the material (W/m.K or W/m oC, Btu/(hr oF ft2/ft))
to = temperature outside pipe or cylinder (K or oC, oF)
ti = temperature inside pipe or cylinder (K or oC, oF)
ln = the natural logarithm
ro = cylinder or pipe outside radius (m, ft)
ri = cylinder or pipe inside radius(m, ft)
http://www.engineeringtoolbox.com/conductive-heat-loss-cylinder-pipe-d_1487.html
Which gives me an heat loss in W. How do I convert the loss in W to a reduction in temperature in °K?