ME 215 Thermodynamics I
Glossary
Additional definitions will be added throughout the semester, as new terms are introduced in class.
adiabatic - a process for which there is no heat transfer. At times, the term "well-insulated" may refer to a system undergoing one or more adiabatic processes.
boundary - A boundary is the interface between a system and its surroundings
cycle - A series of processes that returns the system to the initial state.
density - Density is defined as the mass divided by the volume of a substance. Note that density is equal to one divided by the specific volume.
equilibrium - The term equilibrium refers to a condition where the phenomena or influences capable of affecting a change in the state of a system are balanced.
equilibrium (thermal) - Thermal equilibrium is the condition where two physically connected systems are at the same temperature and therefore the thermal energy of the two systems are in balance.
heat transfer (energy transfer, general definition) - Heat transfer is the transfer of energy across a system's boundaries due to a temperature difference. There are 3 types of heat transfer: conduction, convection, and thermal radiation heat transfer.
heat transfer (conduction) - Conduction is the transfer of energy across a system's boundaries due to inter-molecular interaction.
heat transfer (convection) - Convection is the transfer of energy across a system's boundaries due to the sum of inter-molecular interaction - conduction - and bulk fluid motion)
heat transfer (thermal radiation heat transfer) - Thermal radiation heat transfer is the transfer of energy across a system's boundaries due to the exchange of electromagnetic energy in certain a certain wavelength band (visible light, infrared, and a part of the ultraviolet spectrum).
mass - Mass is the amount of a substance under consideration
mass flow rate - the amount of mass flowing through a cross sectional area per unit time
mole - A mole is the amount of a substance containing 6.022 times 10 to the 23rd power fundamental units. The mass of a substance is equal to the number of moles of a substance times the substance's molar mass.
performance - the ratio of desired output to required input
pressure - Pressure is defined as the force divided by the area over which the force is applied.
pressure (absolute) - Absolute pressure is the pressure relative to a vacuum. Absolute pressure is the gauge pressure plus the pressure associated with the atmosphere.
pressure (gauge) - Gauge pressure is the pressure relative to atmospheric pressure.
process (isobaric) - A process where the pressure remains constant throughout the process.
process (isochoric or isometric) - A process where the the volume is constant throughout the process.
process (isothermal) - A process where the temperature remains constant throughout the process.
process (thermodynamic) - A thermodynamic process is the transition of a system from one state to a different state.
process (quasi-static or quasi-equilibrium) - A quasi-static process is a series of equilibrium states where each state is infinitesimally removed from the equilibrium state just before and just after the state being considered.
property (thermodynamic, general) - Properties represent quantities, variables, used to define the state of a system. Properties do not depend on the path taken to arrive at the property.
property (extensive) - An extensive property is a property that depends upon the size of the system under consideration. Volume and energy are examples of extensive properties.
property (intensive) - An intensive property is a property that does not depend upon the size of the system under consideration. Pressure and temperature are examples of intensive properties.
property (specific) - A specific property is an extensive property divided by the associated system mass.
thermodynamics - The branch of science focusing on transfer of energy and the relationships between the different forms of energy, particularly the transfer of energy due to a temperature difference (heat transfer) and the transfer of energy due to macroscopic force interactions (work).
thermodynamics (Zeroth Law) - If two systems are in thermal equilibrium with a third system, then the two systems are in thermal equilibrium with each other.
thermodynamics (First Law) - The energy of a isolated system does not change. The term isolated implies that the system has no communication with its surroundings, i.e. no mass, momentum, or energy exchange. If such communication exist, then this exchange must be included in any analysis.
thermodynamics (Second Law) - The change in entropy of an isolated system is always greater than or equal to zero. The term isolated implies that the system has no communication with its surroundings, i.e. no mass, momentum, or energy exchange. If such communication exist, then this exchange must be included in any analysis.
thermodynamics (Third Law) - The entropy of a crystalline substance approaches zero as the temperature approaches absolute zero.
state - The state of a system at a given time is described by a listing of its properties.
State Postulate (State Principle) - For a simple, compressible system, knowledge of two independent, intensive thermodynamic properties is required to specific the state of the system.
surroundings (environment) - The surroundings represent everything external to the system.
system (general definition) - A system is the region in space and/or time that is being considered for analysis.
system (closed) - A closed system is a system with a fixed quantity of matter, i.e. there is no mass transfer across the system's boundaries.
system (isolated) - An isolated system is a system for which there is no energy and no mass transfer across the system's boundaries.
system (open) - An open system is a system for which there is both energy and mass transfer across the system's boundaries. An open system is often referred to as a control volume.
volume - Volume is an extensive property and is one representation of the "size" of a system.
volume (specific) - Specific volume is the volume divided by the mass of a substance. Note that specific volume is equal to one divided by the density.
volume (molar specific) - Molar specific volume is the volume divided by the number of moles of a substance. Molar specific quantities are often denoted by a bar over the symbol for the extensive property under consideration.
work (energy transfer) - Work is the energy transfer associated with a forces acting through a distance.
adiabatic - a process for which there is no heat transfer. At times, the term "well-insulated" may refer to a system undergoing one or more adiabatic processes.
boundary - A boundary is the interface between a system and its surroundings
cycle - A series of processes that returns the system to the initial state.
density - Density is defined as the mass divided by the volume of a substance. Note that density is equal to one divided by the specific volume.
equilibrium - The term equilibrium refers to a condition where the phenomena or influences capable of affecting a change in the state of a system are balanced.
equilibrium (thermal) - Thermal equilibrium is the condition where two physically connected systems are at the same temperature and therefore the thermal energy of the two systems are in balance.
heat transfer (energy transfer, general definition) - Heat transfer is the transfer of energy across a system's boundaries due to a temperature difference. There are 3 types of heat transfer: conduction, convection, and thermal radiation heat transfer.
heat transfer (conduction) - Conduction is the transfer of energy across a system's boundaries due to inter-molecular interaction.
heat transfer (convection) - Convection is the transfer of energy across a system's boundaries due to the sum of inter-molecular interaction - conduction - and bulk fluid motion)
heat transfer (thermal radiation heat transfer) - Thermal radiation heat transfer is the transfer of energy across a system's boundaries due to the exchange of electromagnetic energy in certain a certain wavelength band (visible light, infrared, and a part of the ultraviolet spectrum).
mass - Mass is the amount of a substance under consideration
mass flow rate - the amount of mass flowing through a cross sectional area per unit time
mole - A mole is the amount of a substance containing 6.022 times 10 to the 23rd power fundamental units. The mass of a substance is equal to the number of moles of a substance times the substance's molar mass.
performance - the ratio of desired output to required input
pressure - Pressure is defined as the force divided by the area over which the force is applied.
pressure (absolute) - Absolute pressure is the pressure relative to a vacuum. Absolute pressure is the gauge pressure plus the pressure associated with the atmosphere.
pressure (gauge) - Gauge pressure is the pressure relative to atmospheric pressure.
process (isobaric) - A process where the pressure remains constant throughout the process.
process (isochoric or isometric) - A process where the the volume is constant throughout the process.
process (isothermal) - A process where the temperature remains constant throughout the process.
process (thermodynamic) - A thermodynamic process is the transition of a system from one state to a different state.
process (quasi-static or quasi-equilibrium) - A quasi-static process is a series of equilibrium states where each state is infinitesimally removed from the equilibrium state just before and just after the state being considered.
property (thermodynamic, general) - Properties represent quantities, variables, used to define the state of a system. Properties do not depend on the path taken to arrive at the property.
property (extensive) - An extensive property is a property that depends upon the size of the system under consideration. Volume and energy are examples of extensive properties.
property (intensive) - An intensive property is a property that does not depend upon the size of the system under consideration. Pressure and temperature are examples of intensive properties.
property (specific) - A specific property is an extensive property divided by the associated system mass.
thermodynamics - The branch of science focusing on transfer of energy and the relationships between the different forms of energy, particularly the transfer of energy due to a temperature difference (heat transfer) and the transfer of energy due to macroscopic force interactions (work).
thermodynamics (Zeroth Law) - If two systems are in thermal equilibrium with a third system, then the two systems are in thermal equilibrium with each other.
thermodynamics (First Law) - The energy of a isolated system does not change. The term isolated implies that the system has no communication with its surroundings, i.e. no mass, momentum, or energy exchange. If such communication exist, then this exchange must be included in any analysis.
thermodynamics (Second Law) - The change in entropy of an isolated system is always greater than or equal to zero. The term isolated implies that the system has no communication with its surroundings, i.e. no mass, momentum, or energy exchange. If such communication exist, then this exchange must be included in any analysis.
thermodynamics (Third Law) - The entropy of a crystalline substance approaches zero as the temperature approaches absolute zero.
state - The state of a system at a given time is described by a listing of its properties.
State Postulate (State Principle) - For a simple, compressible system, knowledge of two independent, intensive thermodynamic properties is required to specific the state of the system.
surroundings (environment) - The surroundings represent everything external to the system.
system (general definition) - A system is the region in space and/or time that is being considered for analysis.
system (closed) - A closed system is a system with a fixed quantity of matter, i.e. there is no mass transfer across the system's boundaries.
system (isolated) - An isolated system is a system for which there is no energy and no mass transfer across the system's boundaries.
system (open) - An open system is a system for which there is both energy and mass transfer across the system's boundaries. An open system is often referred to as a control volume.
volume - Volume is an extensive property and is one representation of the "size" of a system.
volume (specific) - Specific volume is the volume divided by the mass of a substance. Note that specific volume is equal to one divided by the density.
volume (molar specific) - Molar specific volume is the volume divided by the number of moles of a substance. Molar specific quantities are often denoted by a bar over the symbol for the extensive property under consideration.
work (energy transfer) - Work is the energy transfer associated with a forces acting through a distance.