Thermodynamics and Heat Transfer

Posted this at http://tallbloke.wordpress.com/2014/04/25/critic-of-official-climate-science-tackles-er-sceptics/

I have not bothered to comment on Spencer’s blog because it is difficult to point out errors to someone who does not fully grasp engineering science. Lets start with Thermodynamics. There are some good books around such as Smith, Van Ness & Abbott “Introduction to Chemical Engineering Thermodynamics” McGraw-Hill 1996. Perry’s Chemical Engineering Handbook (McGraw Hill) has a good summary – Section 4 Thermodynamics. There are 5 postulates of Thermodynamics
1/ “There exists a form of energy known as internal energy, which for systems at internal equilibrium is an intrinsic property of the system functionally related to its characteristic coordinates
2/ The total energy of any system and its surroundings is conserved. (Also known as the 1st law of thermodynamics)
3/ There exists a property called entropy, which for systems at internal equilibrium is an intrinsic property of the system functionally related to the measurable coordinates which characterize the system. For reversible processes changes in this property may be calculated by the equation dS=dQ/T
4/ The entropy change of any system and its surrounds, considered together, resulting from any real process is positive, approaching zero when the process approaches reversibility (Also known as the second law of Thermodynamics)
5/ The macroscopic properties of homogeneous PVT systems at internal equilibrium can be expressed as functions of temperature, pressure and composition only.
Section 5 of Perry’s Chemical Engineering Handbook is called Heat and Mass Transfer.
It is an extensive section which requires a good knowledge of maths and makes considerable reference to dimensionless numbers of which (it appears) no climate scientist has any knowledge.
I just point out that there are four types of heat transfer a) conduction, b) convection with sub forms of natural and forced c) phase change and d) radiation.
With respect to radiation it should be pointed out that the Stefan-Boltzmann law/equation applies to surfaces in a vacuum. Engineers use emissivity factors and view factors (corrected by temperature ratios) with the S-B equation to obtain estimates of radiation heat flux in furnaces and heat exchangers plus other equations for convective heat flux.
Finally, instruments which measure temperature need to be properly calibrated and zeroed. (I have measured flame temperatures as high as 3500K) There are no instruments that directly measure radiation flux. Those that supposedly show a result from some mathematical equation need to be understood, calibrated and zeroed. There can be no radiation heat flux from a cool gas 1000′s m in the atmosphere flowing to a surface which is at a higher temperature. The basic premise of AGW with regard to CO2 is nonsense.

Advertisements