C1 - Engines Flashcards
What do heat engines do?
Convert heat energy transferring from hot to cold into work
What type of device converts heat energy transferring from hot to cold into work?
Heat engine
When calculating the efficiency of a heat engine, what is Qout?
Heat energy that leaves the engine
When calculating the efficiency of a heat engine, what symbol is used for the heat energy that leaves the engine?
Qout
When calculating the efficiency of a heat engine, what is Qin?
Heat energy put into the engine
When calculating the efficiency of a heat engine, what symbol is used for the heat energy put into the engine?
Qin
When calculating the efficiency of a heat engine, what is TC?
Temperature of the cold object
When calculating the efficiency of a heat engine, what symbol is used for the temperature of the cold object?
TC
When calculating the efficiency of a heat engine, what is TH?
Temperature of the hot object
When calculating the efficiency of a heat engine, what symbol is used for the temperature of the hot object?
TH
What are the five stages in the operation of a heat engine?
Intake, compression, ignition, expansion, exhaust
What happens during intake in a heat engine?
A fuel and air mixture is taken into the piston
Which stage in the operation of a heat engine involves a fuel and air mixture being taken into the piston?
Intake
What happens to volume and pressure in the piston during intake?
Volume increases. No change in pressure
What happens during compression in a heat engine?
The piston compresses the fuel and air mixture adiabatically
Which stage in the operation of a heat engine involves the piston compressing the fuel and air mixture adiabatically
Compression
What happens to volume and pressure in the piston during compression?
Volume decreases. Pressure increases
What happens during ignition in a heat engine?
The fuel and air mixture is ignited
Which stage in the operation of a heat engine involves the fuel and air mixture being ignited
Ignition
What happens to volume and pressure in the piston during ignition?
Large increase in pressure. No change in volume
What happens during expansion in a heat engine?
The gas expands adiabatically and does work on the piston to push it down
Which stage in the operation of a heat engine involves the gas expanding adiabatically and doing work on the piston to push it down?
Expansion
What happens to volume and pressure in the piston during expansion?
Volume increases. Pressure decreases
What happens during exhaust in a heat engine?
The piston is opened and exhaust gases leave the piston
Which stage in the operation of a heat engine involves the piston opening and exhaust gases leaving the piston?
Exhaust
What happens to volume and pressure in the piston during expansion?
Pressure decreases first, then volume decreases
This graph shows a pressure-volume graph for an ideal heat engine. How would the graph be different for a real heat engine?
The corners would be round and the volume inside the graph would be smaller
