Heat loss from an insulated cylinder

[sicus]

The formula for the heat transfer coefficient for a single layer is 1/U=x/k+1/hi+1/ho

My question is, how is this equation modified for the same single layer, with an added layer of insulation, ho will change in value, but is there just another x/k added in for the second layer?

Also is it correct that k is the same variable as lambda, because i was taught it using lambda in the same place as k.

 

[IRstuff]

Everyone uses slightly different notations. See:

http://en.wikipedia.org/wiki/Heat_transfer#Insulation_and_radiant_barriers

TTFN

FAQ731-376

 

[corus]

I'm not sure why your ho will change in value unless it's related to radiation. The formula you describe is for the resistance so an extra layer will just add another x/k.

Lambda is sometimes used for k, the conductivity.

corus