Presentation on theme: "Understanding Principles of Operation of Internal Combustion Engines"— Presentation transcript:
1 Understanding Principles of Operation of Internal Combustion Engines Lesson 1Understanding Principles of Operation of Internal Combustion Engines
2 Next Generation Science /Common Core Standards Addressed! CCSS.ELA Literacy.RST.9‐10.1 Cite specific textual evidence to support analysis of science and technical texts, attending to the precise details of explanations or descriptions.CCSS.ELA Literacy.RST.9‐ 10.3 Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks, attending to special cases or exceptions defined in the text.CCSS.ELA Literacy. RST.11‐12.2 Determine the central ideas or conclusions of a text; summarize complex concepts, processes, or information presented in a text by paraphrasing them in simpler but still accurate terms.CCSS.ELA Literacy.RST.11‐12.3 Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks; analyze the specific results based on explanations in the text.HSNQ.A.3 Choose a level of accuracy appropriate to limitations on measurement when reporting quantities. (HS‐PS1‐2),(HSPS1‐4),(HS‐PS1‐5),(HS‐PS1‐7)HSSIC.B.6 Evaluate reports based on data. (HS‐LS2‐6)
3 Bell Work / Student Learning Objectives Define internal combustion engine and explain its principal parts.Describe the four events of the internal combustion engine.Explain the differences in operation of four-stroke and two-stroke internal combustion engines.Classify internal combustion engines.
6 Interest ApproachIdentify the different types of internal combustion engines used to power machines.
7 Internal combustion engines and parts A internal combustion engine is a device that converts the energy contained in fuel into rotating powerVarious parts are housed within an engine block
8 4 parts of the engine block 1) Cylinder – the part of the engine block where the combustion takes place. Varies from 1 to 82) Piston – a plunger with rings that fit against the inside cylinder walls and prevent air, fuel, oil from leaking past
9 4 parts of the engine block 3) Connecting rod – connects the piston to the crankshaft. Fastened by the wrist pin4) Crankshaft – shaft with offsets to which the connecting rods are attached
13 Events of the internal combustion engine The internal combustion engine operates based upon the principle of a cycle.A cycle is a series of events that are repeated over and over again.Four strokes make up a cycle: intake, compression, power, exhaust.Two strokes make up a cycle in a two stroke engine – intake/compression, power-exhaust
14 IntakeThe process of getting the fuel and air required for combustion to take place in the chamberExhaust valve remains closed and intake valve is open
15 CompressionThe process of compressing the fuel-air mixture in the combustion chamber to increase the potential chemical energy of the heat from combustion.Both the intake and exhaust valves are closed.
16 PowerThe result of converting the chemical potential energy to mechanical power by the rapid expansion of heated gassesGases produced by the combustion of the compressed fuel-air mixture in the combustion chamber
17 ExhaustThe process of removing the spent products resulting from combustion in the combustion chamber.Exhaust valves opens and spent gasses are forced from the cylinder.
19 Differences between four- and two-stroke engines A four-stroke engine has a series of four events that must be completed within the cycle.A two-stroke engine completes the same series of four events in two strokes.
20 Four-stroke engine 4 events completed in each stroke: Intake CompressionPowerExhaust
21 Two-stroke engine Completes the same four events in two strokes. 1st stroke – release of exhaust gasses drives the piston downward
22 Two-stroke engine2nd stroke – release of exhaust gasses drives the piston downwardReed valves – one-way directional valves that allow the air-fuel mixture to enter the crankcase
24 Classifying internal combustion engines There are many ways by which internal combustion engines are classifiedPiston strokesEngine powerNumber of cylindersEngine displacementCylinder arrangementFuel ignition
26 Engine power Small engines – produce less than 25 horsepower Large engines – produce more than 25 horse power
27 Number of cylinders Single-cylinder – engines have only one cylinder Multi-cylinder – engines have 2, 3, 4, 5, 6, 8, or more cylinders
28 Engine displacementDescribes the total swept volume of the engine cylinders as pistons complete one strokeExpressed as either cubic inches or cubic centimeters
29 Cylinder arrangementIn-line – all of the cylinders are in a straight lineVee-block – cylinders arranged in a “V” configurationFlat – cylinder arrangements are perpendicular, or flat, in the relation to the earth
30 Fuel ignition Gasoline engines – fuel-powered by a spark ignition Diesel engines – use glow plugs and fuel in compression ignition
31 Characteristics of two- and four-stroke engines Two-stroke Cycle EnginesFour-Stroke Cycle EnginesLighter weightOperates in many positionsHigher power to weight ratioEngine oil usually mixed withfuelLouder operationHigher Engine speedsMore vibrationRough idling operationHeavier weightOperates in limited positionsLower power to weight ratioEngine oil in a reservoirQuieter operationSlower engine speedsSmoother operationSmoother idling operation
32 Review/SummaryWhat is an internal combustion engine? What are its principal parts?Describe the four events of the internal combustion engine.Explain the difference between four- and two-stroke internal combustion enginesHow are internal combustion engines classified?