Question

Define the following terms related to reciprocating engines: stroke, bore, top dead center, and clearance volume.

Short answer

In a reciprocating engine, the four key terms are: 1. Stroke - the linear distance a piston travels within a cylinder, directly affecting the engine's displacement and power output. 2. Bore - the internal diameter of an engine's cylinder, used alongside stroke to calculate engine displacement and potential power and torque production. 3. Top Dead Center (TDC) - the position of the piston when it reaches its highest point in the cylinder, marking the completion of the compression stroke. 4. Clearance Volume - the volume remaining in the combustion chamber when the piston is at TDC, essential in determining an engine's compression ratio, thermal efficiency, and power output.

Step-by-step solution

Define Stroke

Stroke is the linear distance that a piston travels within a cylinder in a reciprocating engine. During a full cycle of operation, the piston travels twice the stroke length. This distance is essential since it directly affects an engine's displacement and power output.

Define Bore

The bore is the internal diameter of an engine's cylinder. It represents the size of the piston's working space and, together with the stroke, is used to calculate an engine's displacement. The larger the bore and stroke, the higher the displacement, and potentially more power and torque the engine can produce.

Define Top Dead Center

Top Dead Center (TDC) refers to the position of the piston in a reciprocating engine when it reaches its highest point in the cylinder during its stroke. At this point, the piston has completed the compression stroke, and all the compressed air and fuel mixture is contained in a small space right before ignition.

Define Clearance Volume

Clearance Volume is the volume remaining in the combustion chamber when the piston is at Top Dead Center (TDC). This volume is crucial in determining an engine's compression ratio – the ratio between the total volume (cylinder volume + clearance volume) and the clearance volume when the piston is at Bottom Dead Center (BDC). A higher compression ratio means higher thermal efficiency and power output.