Search results
Results from the WOW.Com Content Network
Top dead center in a gasoline engine. In a reciprocating engine, the dead centre is the position of a piston in which it is either farthest from, or nearest to, the crankshaft. The former is known as top dead centre (TDC) while the latter is known as bottom dead centre (BDC). [1] Position of pistons
Phase 2 (top dead centre) When the piston reaches top dead centre, the inlet valve is open, releasing the vacuum. the flywheel keeps the piston moving; Phase 3 (heating up the work medium, expansion stroke) when the piston is moving away from the heat source, the air is pushed toward the heat source.
Diagram showing the operation of a 4-stroke SI engine. Labels: 1 ‐ Induction 2 ‐ Compression 3 ‐ Power 4 ‐ Exhaust. The top dead center (TDC) of a piston is the position where it is nearest to the valves; bottom dead center (BDC) is the opposite position where it is furthest from them.
This stroke of the piston begins at top dead center (T.D.C.) and ends at bottom dead center (B.D.C.). In this stroke the intake valve must be in the open position while the piston pulls an air-fuel mixture into the cylinder by producing a partial vacuum (negative pressure) in the cylinder through its downward motion.
The first person to build a working four-stroke engine, a stationary engine using a coal gas-air mixture for fuel (a gas engine), was German engineer Nicolaus Otto. [4] This is why the four-stroke principle today is commonly known as the Otto cycle and four-stroke engines using spark plugs often are called Otto engines.
Engine designers aim to close the exhaust valve just as the fresh charge from the intake valve reaches it, to prevent either loss of fresh charge or unscavenged exhaust gas. In the diagram, the valve overlap periods are indicated by the overlap of the red and blue arcs. Key: TDC = Top dead centre; BDC = Bottom dead centre; IO = Inlet valve opens
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Main page; Contents; Current events; Random article; About Wikipedia; Contact us; Donate