Lec 5-6 Flashcards
Rate of accumulation of momentum in a system
d/dt (integral (rho * velocity vector * dV) over volume of system
momentum conservation
Rate of momentum accumulation = net rate that momentum enters (convection) - rate of momentum production
What is momentum production
Sum of the forces acting on the system
(pressure force, gravity)
How does momentum enter a system
Via convection
How is momentum generated
Through external force acting on a system
Energy conservation
Rate of energy accumulation in the system = net rate E enters + rate energy is produced
How can energy be added to a system
Qs : heat added through system and boundaries
- Heat added to the system through the surface
- Heat added at the inlets and outlets by conduction and radiation.
AND
Net energy added to the system by convection at the inlets and outlets
How is energy produced in a system
Rate at which work is done by the surroundings on the system
AND
Rate at which heat is generated within the system
How is work done by fluid
Shaft work
Friction (inlets outlets)
Pressure force (inlets outlets)
