[Introduction to Thermodynamics of Materials] CH01. Introduction and Definition of Terms

1.1 Introduction

Thermodynamics

"Thermodynamics is concerned with the behavior of matter and the transformation between different forms of energy on a macroscopic scale, where matter is anything that occupies space."

• definitions of terms
  - system: the matter or substance which is subject of a thermodynamic analysis
  - surrounding: outside the system which may interact with system by exchanging energy or matter
  - boundary or wall: between system and surrounding, what allows such interaction
  - interaction: only via pressure and temperature change, the system and the surrounding interacts

• What does thermodynamics do?
  • systems with equilibrium state $-$work & heat$\rightarrow$ new equilibrium state
    1) description of the equilibrium state
    2) description of the change in equilibrium state
  • c.f) kinetics: how fast

1.2 The Concept of State

$V=V(P, T)$

$\rightarrow$ 독립변수 $P$, $T$에 대하여 부피 $V$는 $P$, $T$에 대해 변하는 종속변수

Path-independent property

$dV = (\frac{\partial V}{\partial P})_T dP+(\frac{\partial V}{\partial T})_P dT$

• volume of the gas: state function

1.4 The Equation of State of An Ideal Gas

Boyle's Law

$P \varpropto \frac{1}{V}$

Charles' Law

$T \varpropto V$

Reference

• 2023-2 DGIST 재료열역학 수업 강의자료, Thermodynamics_2023-2_Chapter 1