Engines Chapter 6 Flashcards

Questions and Answers

__________ is the burning of fuel, or chemical reaction between fuel and oxygen that releases heat.

Combustion

What is a machine used to convert heat energy produced from burning fuel into mechanical power?

Engine

When the chemical bonds between a fuels and atoms are broken and oxygen attaches to fuel molecules, heat is released.

Hydrogen

________ is used to describe engines used in off-road equipment, locomotives, and electrical generators.

Prime Mover (Power Unit) Signup and view all the answers

When looking at the Piston, which way does the flywheel turn?

Clockwise or Counter-clockwise Signup and view all the answers

What is the diameter of a cylinder called?

Bore Signup and view all the answers

What is the distance traveled by the piston from the top to the bottom of the cylinder?

Stroke Signup and view all the answers

What is the ratio between a cylinder's bore and stroke?

Stroke Ratio Signup and view all the answers

An engine that has equal, or nearly equal, bore and stroke dimensions is called a __________ engine.

Square Signup and view all the answers

An engine with a stroke dimension that is longer than the bore dimension is called an __________ engine.

Under-Square (Long-Stroke) Signup and view all the answers

An engine with a stroke that is shorter than the bore diameter is known as an __________ engine.

Over-Square Signup and view all the answers

What do TDC and BDC stand for?

Top Dead Center and Bottom Dead Center Signup and view all the answers

The volume displaced by the piston as it moves from TDC and BDC is called _________.

Cylinder Displacement Signup and view all the answers

What is the formula for calculating Cylinder Displacement?

(pi) x Radius^2 x Stroke Signup and view all the answers

What is the volume of all the cylinders in an engine known as?

Total Cylinder Displacement Signup and view all the answers

What is the formula for Total Cylinder Displacement?

(pi) x Radius^2 x Stroke x Number of Cylinders Signup and view all the answers

The space remaining in a cylinder when the piston is at TDC is called __________ volume.

Clearance Signup and view all the answers

What is the sum of the cylinder displacement plus clearance volume called?

Total Cylinder Volume Signup and view all the answers

What is a comparison of total cylinder volume to clearance volume known as?

Compression Ratio Signup and view all the answers

A __________ increase in an engine decreases fuel consumption and increases power exponentially.

Compression Ratio Signup and view all the answers

__________ is the largest structure of an engine that encloses the cylinders.

Cylinder Block Signup and view all the answers

The lower portion of the engine, which contains the crankshaft, is called the __________.

Crankcase Signup and view all the answers

The __________ is usually a heavy metal casting that seals the top of the engine to form a combustion chamber above the pistons.

Cylinder Head Signup and view all the answers

__________ converts the reciprocating action of the pistons into rotational movement.

Crankshaft Signup and view all the answers

What is the part of the crankshaft that connects with the connecting rod?

Crankpin Signup and view all the answers

What are the main components of a cylinder?

Piston, piston rings, wrist pin, and connecting rod Signup and view all the answers

________ are used to minimize gas leakage past the piston.

Piston Rings Signup and view all the answers

What is used to control the movement of gases into and out of the cylinder?

Poppet-Type Valves Signup and view all the answers

What direction does air enter the cylinders?

Swirl Signup and view all the answers

________ is used to operate the valves in the correct sequence.

Camshaft Signup and view all the answers

What is used to coordinate the movement of the crankshaft with the camshaft and the valves?

A Gear train or valve timing mechanism Signup and view all the answers

________ is a heavy, round casting bolted to the end of the crankshaft to smooth out the firing stroke.

Flywheel Signup and view all the answers

Engines are machines that convert ________ into mechanical power.

Heat Signup and view all the answers

________ is a measurement of rotational force, or twisting force.

Torque Signup and view all the answers

What is the difference between engine torque at its peak compared to torque at the maximum or rated rpm?

Torque Rise Signup and view all the answers

What can be used to determine whether the problem is in the engine or transmission when low power or poor engine performance is reported?

Stall Test Signup and view all the answers

What is the calculation of the rate at which work is performed; measuring an engine's power output as a function of both torque and engine speed?

Horsepower (HP) Signup and view all the answers

A ________ is used to measure engine or vehicle road speed and torque to calculate engine power.

Dynamometer Signup and view all the answers

________ is the power output of an engine measured at the maximum engine speed under standardized conditions.

Rated Horsepower Signup and view all the answers

What is the amount of energy an engine converts into mechanical energy compared to what could theoretically be extracted from a pound of fuel?

Thermal Efficiency Signup and view all the answers

__________ is the average pressure exerted on the crown of a piston during the power stroke.

Brake Mean Effective Pressure (BMEP) Signup and view all the answers

What is a comparison between the volume of air actually filling a cylinder and what it is theoretically capable of holding?

Volumetric Efficiency Signup and view all the answers

Some diesels today are capable of running more than ________% volumetric efficiency with high-pressure turbocharging.

300 Signup and view all the answers

An engine that burns fuel outside of a cylinder is called an __________ combustion engine.

External Signup and view all the answers

An engine that burns fuel inside the cylinder is known as an __________ combustion engine.

Internal Signup and view all the answers

________ are the most common type of internal combustion engine, using pistons moving up and down.

Reciprocating Engines Signup and view all the answers

What are the four operating cycles of a four-stroke cycle?

Intake, compression, power, exhaust (suck, squeeze, bang, blow) Signup and view all the answers

Why do four-stroke cylinders operate differently?

Longer Piston Stroke, Little piston movement, adaptations for turbocharging, large valve overlap Signup and view all the answers

TF: Changing the timing when the intake valve opens and closes can improve engine performance and increase volumetric efficiency.

True Signup and view all the answers

What is the peak pressure of a piston?

3750 psi (259 bar) Signup and view all the answers

What occurs when both intake and exhaust valves are open together at the beginning of the intake stroke and end of the exhaust stroke?

Valve Overlap Signup and view all the answers

________ is the process of cleaning exhaust gases from the cylinder.

Scavenging Signup and view all the answers

What is the variation of a four-stroke cycle diesel engine that divides a five-stroke cycle into two events?

Miller Cycle Signup and view all the answers

What percentage of NOx is reduced when using the Miller Cycle?

30% Signup and view all the answers

What performs all of the same combustion cycle events of a four-stroke engine, accomplished with two strokes of the piston?

Two-Stroke Engine Signup and view all the answers

What type of technology does EcoMotors use in their two-stroke engines?

Opposed-piston, opposed-cylinder (OPOC) Signup and view all the answers

What are some advantages of the Navistar's EcoMotors EM100?

<ul> <li>50% fewer parts</li> <li>Lower production costs</li> <li>15-20% better fuel economy</li> <li>High thermal efficiency for cooling system</li> <li>Ultra-low exhaust emissions</li> </ul> Signup and view all the answers

________ are used to remove excess heat produced by the combustion process from an engine.

Cooling Systems Signup and view all the answers

TF: Because diesel engines have less natural retarding force to slow a vehicle than a throttled SI engine, diesels often have an engine-based system to supplement service brake operation.

True Signup and view all the answers

What are the functions of a lubrication system?

<ul> <li>Clean and carry soot away</li> <li>Cool engine parts</li> <li>Reduce friction in the engine</li> <li>Enhance gas-tight sealing</li> <li>Reduce engine noise</li> </ul> Signup and view all the answers

TF: The exhaust system removes the excess heat and combustion gases from the Engine's Exhaust.

False Signup and view all the answers

Study Notes

Combustion and Engine Basics

Combustion is the process of burning fuel through a chemical reaction with oxygen, releasing heat.
An engine converts the heat energy from burning fuel into mechanical power.
Hydrogen and oxygen atoms' bonds break during combustion, allowing oxygen to latch onto fuel molecules and release heat.

Engine Components

A prime mover, also called a power unit, is an engine utilized in off-road equipment, locomotives, and electrical generators.
The bore refers to the diameter of a cylinder, while stroke indicates the distance a piston travels within it.
Stroke ratio is the comparison of bore to stroke dimensions, determining engine design characteristics.
Cylinder displacement (or swept volume) is the volume a piston displaces as it moves from the top dead center (TDC) to bottom dead center (BDC).

Engine Design Types

A square engine has equal bore and stroke dimensions.
An under-square engine has a longer stroke than bore.
An over-square engine features a shorter stroke than bore, optimizing performance for high-speed operations.

Cylinder and Volume Concepts

Clearance volume is the remaining space in a cylinder when the piston is at TDC.
Total cylinder volume combines cylinder displacement with clearance volume.
Compression ratio compares total cylinder volume to clearance volume, impacting fuel efficiency and power output.

Engine Structure and Function

The cylinder block is the primary engine structure, enclosing cylinders and supporting various components like crankshaft and camshaft.
The crankcase houses the crankshaft, while the cylinder head forms the combustion chamber above the pistons.
The crankshaft converts piston's reciprocating motion into rotational movement.

Key Engine Measurements and Outputs

Torque is the rotational force calculated by multiplying applied force by lever length.
Horsepower (HP) quantifies the rate of work done by the engine, factoring both torque and speed.
A dynamometer measures engine torque and road speed to calculate power output.

Engine Efficiency and Performance Metrics

Thermal efficiency indicates the energy converted into mechanical power relative to fuel energy potential.
Volumetric efficiency measures the actual air volume filling a cylinder against its theoretical capacity.
Compression ratio increases lead to reduced fuel consumption and significantly enhanced power.

Engine Types

External combustion engines burn fuel outside the cylinder (e.g., steam engines), while internal combustion engines do so within the cylinder.
Reciprocating engines are the most prevalent internal combustion designs, featuring pistons that generate rotational motion.

Engine Processes and Cycles

Four-stroke engines operate with four cycles: intake, compression, power, exhaust (suck, squeeze, bang, blow).
Scavenging is the process of clearing exhaust gases from the cylinder, enhancing efficiency.

Advancements and Innovations

The Miller cycle reduces nitrogen oxides (NOx) emissions by approximately 30%, utilizing a variation of the four-stroke cycle.
Two-stroke engines perform the entire combustion cycle twice per crankshaft revolution, leading to a simpler design.

Lubrication and Cooling Systems

Cooling systems remove excess heat generated during combustion to maintain optimal engine temperatures.
The lubrication system serves multiple functions: cleaning, reducing friction, cooling, gas-tight sealing, and suppressing noise.

Engine Dynamics and Adjustments

Valve timing adjustments can improve engine performance and volumetric efficiency by altering intake and exhaust flow dynamics.

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Test your knowledge on key terms from Chapter 6 of Engines. This set of flashcards covers essential concepts such as combustion, engine mechanics, and the role of hydrogen and oxygen in fuel reactions. Perfect for students looking to reinforce their understanding of engine fundamentals.

Engines Chapter 6 Flashcards

Questions and Answers

__________ is the burning of fuel, or chemical reaction between fuel and oxygen that releases heat.

What is a machine used to convert heat energy produced from burning fuel into mechanical power?

When the chemical bonds between a fuels ________ and ________ atoms are broken and oxygen attaches to fuel molecules, heat is released.

________ is used to describe engines used in off-road equipment, locomotives, and electrical generators.

When looking at the Piston, which way does the flywheel turn?

What is the diameter of a cylinder called?

What is the distance traveled by the piston from the top to the bottom of the cylinder?

What is the ratio between a cylinder's bore and stroke?

An engine that has equal, or nearly equal, bore and stroke dimensions is called a __________ engine.

An engine with a stroke dimension that is longer than the bore dimension is called an __________ engine.

An engine with a stroke that is shorter than the bore diameter is known as an __________ engine.

What do TDC and BDC stand for?

The volume displaced by the piston as it moves from TDC and BDC is called _________.

What is the formula for calculating Cylinder Displacement?

What is the volume of all the cylinders in an engine known as?

What is the formula for Total Cylinder Displacement?

The space remaining in a cylinder when the piston is at TDC is called __________ volume.

What is the sum of the cylinder displacement plus clearance volume called?

What is a comparison of total cylinder volume to clearance volume known as?

A __________ increase in an engine decreases fuel consumption and increases power exponentially.

__________ is the largest structure of an engine that encloses the cylinders.

The lower portion of the engine, which contains the crankshaft, is called the __________.

The __________ is usually a heavy metal casting that seals the top of the engine to form a combustion chamber above the pistons.

__________ converts the reciprocating action of the pistons into rotational movement.

What is the part of the crankshaft that connects with the connecting rod?

What are the main components of a cylinder?

________ are used to minimize gas leakage past the piston.

What is used to control the movement of gases into and out of the cylinder?

What direction does air enter the cylinders?

________ is used to operate the valves in the correct sequence.

What is used to coordinate the movement of the crankshaft with the camshaft and the valves?

________ is a heavy, round casting bolted to the end of the crankshaft to smooth out the firing stroke.

Engines are machines that convert ________ into mechanical power.

________ is a measurement of rotational force, or twisting force.

What is the difference between engine torque at its peak compared to torque at the maximum or rated rpm?

What can be used to determine whether the problem is in the engine or transmission when low power or poor engine performance is reported?

What is the calculation of the rate at which work is performed; measuring an engine's power output as a function of both torque and engine speed?

A ________ is used to measure engine or vehicle road speed and torque to calculate engine power.

________ is the power output of an engine measured at the maximum engine speed under standardized conditions.

What is the amount of energy an engine converts into mechanical energy compared to what could theoretically be extracted from a pound of fuel?

__________ is the average pressure exerted on the crown of a piston during the power stroke.

What is a comparison between the volume of air actually filling a cylinder and what it is theoretically capable of holding?

Some diesels today are capable of running more than ________% volumetric efficiency with high-pressure turbocharging.

An engine that burns fuel outside of a cylinder is called an __________ combustion engine.

An engine that burns fuel inside the cylinder is known as an __________ combustion engine.

________ are the most common type of internal combustion engine, using pistons moving up and down.

What are the four operating cycles of a four-stroke cycle?

Why do four-stroke cylinders operate differently?

TF: Changing the timing when the intake valve opens and closes can improve engine performance and increase volumetric efficiency.

What is the peak pressure of a piston?

What occurs when both intake and exhaust valves are open together at the beginning of the intake stroke and end of the exhaust stroke?

________ is the process of cleaning exhaust gases from the cylinder.

What is the variation of a four-stroke cycle diesel engine that divides a five-stroke cycle into two events?

What percentage of NOx is reduced when using the Miller Cycle?

What performs all of the same combustion cycle events of a four-stroke engine, accomplished with two strokes of the piston?

What type of technology does EcoMotors use in their two-stroke engines?

What are some advantages of the Navistar's EcoMotors EM100?

________ are used to remove excess heat produced by the combustion process from an engine.

TF: Because diesel engines have less natural retarding force to slow a vehicle than a throttled SI engine, diesels often have an engine-based system to supplement service brake operation.

What are the functions of a lubrication system?

TF: The exhaust system removes the excess heat and combustion gases from the Engine's Exhaust.

Study Notes

Combustion and Engine Basics

Engine Components

Engine Design Types

Cylinder and Volume Concepts

Engine Structure and Function

Key Engine Measurements and Outputs

Engine Efficiency and Performance Metrics

Engine Types

Engine Processes and Cycles

Advancements and Innovations

Lubrication and Cooling Systems

Engine Dynamics and Adjustments

Studying That Suits You

Description

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