Fundamentals of thermodynamics, Study notes of Thermodynamics

Download Fundamentals of thermodynamics and more Study notes Thermodynamics in PDF only on Docsity!  Ready to study? Start with Flashcards Part 1:Thermodynamics- Fundamental Concepts and Definitions 48 terms by jacob_henley  Download the Android app! × Applied Thermodynamics The application of basic thermodynamics for the solution of engineering problems. Thermodynamics The Basic science that deals with the conversion of heat into mechanical work. Science which deals with the computation of energy, exergy and entropy. entropy the portion of heat energy which is not available for conversion into work is measured by this thermodynamic property. Exergy The part of heat which is available for conversion into maximum work. Zeroth Law Equality of temperature, helps in measurement of temperature.. First Law Law of conservation of energy and introduces the concept of internal energy. Second Law Puts limit on the amount of conversion of heat into work and introduces the principle of increase of entropy. Third law defines absolute zero of entropy. Scope of thermodynamics mechanical, chemical, metallurgical,automobile, aerospace, marine, textile, energy technology and environmental engineering.Wherever there is combustion,heating or cooling, exchange of heat for carrying out chemical reactions,ect.. System a region or quantity of matter is identified as this for the study and analysis of a problem. Its then isolated from the surrounding through a real or imaginary boundary. Continuum makes no hypothesis about the structure of matter of the system. its refereed to as this; continuous distribution of matter. macroscopically time averaged measured values of the properties of the system. Quasi static process used and it is assumed that the system is very near to equilibrium state during a process. Thermodynamic system Their is a boundary, and then their is a surrounding. The boundary exchanges mass and energy with the surrounding.(ex. Earth) Adiabatic boundary The walls do not allow heat transfer to take place across them. For example, insulated walls of a geyser. Diathermic Boundary The walls allow heat interaction between the system and the surrounding. For example, hot plate, heat exchange tubes. Pure substance has homogeneous and invariable chemical composition even though there is a change of phase. example: The mixture of liquid air and gaseous air is not a pure substance. What does matter consist of? Large number of molecules which are in a random state of motion.They experience inter- molecular force of attraction and repulsion...Matter is neither continuous nor homogenous. carburetor open system, inflow=fuel+air, outflow:fuel-air mixture radiator of car open system, Inflow= hot water & cold air, outflow= cooled water and hot air. energy inflow= heat of water, outflow = heat of air car battery closed system, energy inflow= electricity during charging, outflow energy= electricity during discharging. kitchen refrigerator closed, energy inflow= electricity, outflow= heat from radiator. macroscopic point of view the system is considered a continuum.measured values which are time averaged variables. Used in classical thermodynamics. sufficient accuracy and validity. engineering devices are designed and analysed macroscopically. approach is simple and quick. Microscopic point of view: The system is considered to contain large number of molecules moving in chaotic fashion.Properties are found out by statistically averaging the behavior of individual molecules. It is used in statistical thermodynamics. Results are very accurate. For research and study of laws of thermodynamics deeply, microscopic study is used. Complex, cumbersome and time consuming. Specific volume formula v= v/m[m^3/k] Mass Density Formula p=m/v weight w=mg Specific weight w= W/V Pressure formula p=F/A[N/m^2] 1 pascal 1 n/m2 1 kPa (kilopascal) 10^3 Pa 1 MPa(Megapascal) 10^6 Pa 1 Bar 10^5 n/m^2= 10^5 Pascal 1 atm 101.325 kPa= 1.01325 bar Pressure exerted by 1 mm column of mercury is called Torr 1 bar= 750 mm of mercury = 750 Torr =100 kPa Pressure at a given point can be specified relative Zero Pressure or to atmospheric pressure The pressure relative to absolute zero pressure Absolute pressure Pressure relative to atmosphere is called Gauge pressure absolute pressure=***** pressure+ atmospheric pressure If the pressure is less than atmosphere, use this formula p2= Pat-Pvac