thermo units 1/2

convection

heat transfer btwn solid surface and adjacent liquid/gas

radiation

energy transfer by electromagnetic waves

thermal efficiency

measure of how efficiently a power cycle converts the heat it recieves to work

coefficient of performance, B

efficiency of a refrigerator

coefficient of performance, y

efficiency of a heat pump

forced convection

fluid is forced to flow

conduction

when object is heated, molecules gain more energy, vibrate more and bump into nearby molecules and transfer energy to them (in solids, liquids, and gas)

adiabatic process

no heat transfer (D=0)

heat flux

rate of heat transfer per unit of system surface area

heat

form of energy transferred by virtue of temp difference

polytropic process

process where pressure and volume are related by PV^n = constant or Pv^n = constant

rigid tank

no change in volume, mechanical work =0

quasistatic/quasisequilibrium process

system remains infinitesimally close to equilibrium state at all times

point functions

depend on state only (volume, temp, energy, pressure)

path functions

depend on path of process (work, heat)

isothermal process

temp remains constant

isobaric process

pressure remains constant

isochoric (isometric) process 

specific volume stays constant

steady state

no properties change with time

extensive properties

depend on size of system (mass, volume, energy)

intensive properties

values are independent of size of system (pressure, temp)is

isolated system

special type of closed system that does not interact in any way with its surroundings (no energy or mass transfer)

closed system

no transfer of mass across boundary can occur

control volume

region of space thru which mass flows (mass and energy can pass boundary)

mechanical equil

no change in pressure at any point

thermal equil

temp is same thruout system

chemical equil

chemical composition does not change

phase equil

mass of each phase reaches an equil level