Thermodynamics Flashcards
What must fluids that exceed Mach 3 be considered?
Compressible
What is “e” is a thermodynamic equation
Internal energy of the system, which is the energy of motion of all the gas molecules.
What are two ways to change a system’s internal enerygy?
- Heat is added ore removed across the system boundry. σq is the heat added per unit mass
- Work is done on the system by pushing the boundry in, or by the system in pushing the boundry out. σw is the work added per unit mass
What is a system?
Unit mass of gas inside a flexible boundry.
What is de?
The incremental change in internal energy of the system per unit mass
What is the First Law of Thermodynamics?
σq + σw = de
What does work on the system?
Pressure “p”
What is dA?
Incremental surface area of the boundary
What is the work done on the pressure system and what is the distance?
“Delta”W
”s”
What is “Delta”W
Force X Distance
(p dA)s
Waht is the incremental work done on the system by pressure p?
σw = (A to some other A)(pdA)s
What is dv if the volume is moving in?
Negative
What is the work done on system, σw, if the boundry is moved in?
Positive
