The duality of internal energy of ideal gas

作     者：Tian Zhao Zengyuan Guo 

作者机构：Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering MechanicsTsinghua University 

出 版 物：《Science Bulletin》 (科学通报（英文版）)

年 卷 期：2015年第60卷第15期

页      面：1355-1358页

核心收录：

学科分类：080701[工学-工程热物理] 08[工学] 0807[工学-动力工程及工程热物理] 080101[工学-一般力学与力学基础] 0801[工学-力学（可授工学、理学学位）] 

基　　金：supported by the National Natural Science Foundation of China(51136001 and 51356001) Tsinghua University Initiative Scientific Research Program and Science Fund for Creative Research Groups(51321002) 

主　　题：Internal energy Mechanical energy Ideal gas Duality 

摘      要：This contribution starts with the discussion on the classification of energy, and then the behaviors of various thermodynamic processes are analyzed, accompanying with the comparison of the adiabatic compression process of an ideal gas and an elastic rod. All these analyses show that the internal energy of ideal gases exhibits the duality of thermal energy–mechanical energy, that is,the internal energy acts as the thermal energy during the isochoric process, while the internal energy acts as the mechanical energy during the isentropic process. Such behavior of the internal energy is quite different from other types of energy during the energy conversion process because the internal energy of ideal gases exhibits the duality of thermal energy–mechanical energy. Because of this duality, the internal energy of ideal gas is proposed to be refered to as thermodynamic energy rather than thermal energy as indicated in some literature, although it consists of kinetics of the microscopic random motion of particles and can be expressed as the function of temperature only.