Thermodynamic origin and graphical methods of phase theory
- 40 Downloads
Thermodynamics is often considered difficult to understand due to extensive use of mathematics. In the present paper, a graphical approach will be used to explain the origin of phase diagrams starting from the fundamental equation of thermodynamics dU = Tds − Pdv defined by J.W. Gibbs. The characteristic variables of this equation are the specific entropy s and the specific volume v, which lead in a straightforward way to s-v phase diagrams. It will be demonstrated through monotonicity of the internal energy curves of the different phases of the system and graphical Legendre transformations how pressure-entropy (P-s) and temperature-volume (T-v) phase diagrams are linked to s-v phase diagrams and how the latter two phase diagrams are related to pressure-temperature (P-T) phase diagrams.
Unable to display preview. Download preview PDF.
- 1.J.W. Gibbs, Trans. Conn. Acad. 2, 309 (1873)Google Scholar
- 2.J.W. Gibbs, The Collected Works of J.W. Gibbs – Volume 1: Thermodynamics (Green & Co, NY, 1928)Google Scholar
- 5.J.W. Gibbs, Trans. Conn. Acad. 3, 108 (1875)Google Scholar
- 6.J.W. Gibbs, Trans. Conn. Acad. 3, 343 (1877)Google Scholar
- 7.J.W. Gibbs, Trans. Conn. Acad. 2, 382 (1873)Google Scholar
- 8.J.W. Gibbs, The Scientific Papers of J. Willard Gibbs in Two Volumes, Vol I: Thermodynamics (Longmans, Green & Co, London, 1906)Google Scholar