上游充通大学 SHANGHAI JIAO TONG UNIVERSITY Engineering Thermodynamics I Lectures 3-4 Spring,2019 Prof.,Dr.Yonghua HUANG 强 A月是 http://cc.sjtu.edu.cn/G2S/site/thermo.html AN 1日G
Engineering Thermodynamics I Lectures 3-4 Spring, 2019 Prof., Dr. Yonghua HUANG http://cc.sjtu.edu.cn/G2S/site/thermo.html
Chapter 1 Concepts,Systems Units ④Objective fundamental concepts:including closed system,control volume,boundary and surroundings,property,state, process,the distinction between extensive and intensive properties,and equilibrium. apply SI Engineering units. Kelvin,Rankine,Celsius,and Fahrenheit temperature scales. apply the problem-solving methodology. 上游气通大粤 February 28,2019 2 SHANGHAI JLAO TONG UNIVERSITY
February 28, 2019 2 Chapter 1 Concepts, Systems & Units Objective • fundamental concepts: including closed system, control volume, boundary and surroundings, property, state, process, the distinction between extensive and intensive properties, and equilibrium. • apply SI Engineering units. • Kelvin, Rankine, Celsius, and Fahrenheit temperature scales. • apply the problem-solving methodology
1.1 System and Surroundings Thermodynamic system -Any three-dimensional region of space bounded by one or more arbitrary geometric surfaces SURROUNDINGS Surroundings SYSTEM -The region of space outside the arbitrary boundaries BOUNDARY Abstraction of system Air Air actuating shaft gasoline gasoline Automobile engine actuating shaft Boundary > exhaust gas (a) (h) 上游充通大学 February 28,2019 3 SHANGHAI JLAO TONG UNIVERSITY
February 28, 2019 3 1.1 System and Surroundings Thermodynamic system –Any three-dimensional region of space bounded by one or more arbitrary geometric surfaces Surroundings –The region of space outside the arbitrary boundaries Abstraction of system Automobile engine
Boundary Imaginary boundary System boundary may be real or it could be imaginary The system may be stationary or moving rigid stationary boundary chimney Gas air imaginary boundary exhausted rigid moving boundary gas imaginary boundary diffuser compressor burner gas turbine nozzle 上游充通大学 February 28,2019 4 SHANGHAI JLAO TONG UNIVERSITY
February 28, 2019 4 Boundary System boundary may be real or it could be imaginary The system may be stationary or moving Imaginary boundary chimney
Types of Systems System interaction with its surroundings: Mass No Closed ·mass/energy system Closed System m=constant allows transfer of energy only across its boundaries; Energy Yes no mass transfer 。 Chemical composition within the system may change;but mass remains constant (volume may change) boundary Closed System Control Mass [CM] mass YES Open System Open allows both transfer of energy and mass system Open system=Control volume [CVI energyYES Simple compressible system:consists of compressible fluids,only volume change work (reversible)exchanged 上游充通大 February 28,2019 5 SHANGHAI JLAO TONG UNIVERSITY
February 28, 2019 5 Types of Systems System interaction with its surroundings: • mass /energy Closed System allows transfer of energy only across its boundaries; no mass transfer • Chemical composition within the system may change; but mass remains constant (volume may change) • Closed System = Control Mass [CM] Open System allows both transfer of energy and mass • Open system= Control volume [CV] Simple compressible system: consists of compressible fluids, only volume change work (reversible) exchanged Open system