earth's interior heat is the engine that powers
Earth's internal heat budget Earth's internal heat powers most geological processes[3] and drives plate tectonics.[2] Despite its geological significance, this heat energy coming from Earth's interior is actually only 0.03% of Earth's total energy budget at the surface, which is dominated by 173,000Â TW of incoming solar radiation.[4] The insolation that eventually, after reflection, reaches the surface penetrates only several tens of centimeters on the daily cycle and only several tens of meters on the annual cycle. This renders solar radiation minimally relevant for internal processes.[5]
Two-stroke diesel engine Two-stroke internal combustion engines are simpler mechanically than four-stroke engines, but more complex in thermodynamic and aerodynamic processes, according to SAE definitions. In a two-stroke engine, the four "cycles" of internal combustion engine theory (intake, compression, ignition, exhaust) occur in one revolution, 360 mechanical degrees, whereas in a four-stroke engine these occur in two complete revolutions, 720 mechanical degrees. In a two-stroke engine, more than one function occurs at any given time during the engine's operation.