Fundamentals of Internal Combustion Engines - IC Engines

Name: Fundamentals of Internal Combustion Engines - IC Engines
Rating: 4.3 (136 reviews)

Engine Performance, Power, Torque, Efficiency, Compression Ratio, Otto, Diesel, Dual, Miller cycles and more

Created byProf. Samer

Last updated 7/2021

English

English [Auto],

What you'll learn

Understand How a Car Engine Work: Four-Stroke and Two-Stroke Engines
Recognize Engine Geometry and Related Terminology: Piston, TDC, BDC, Bore, Stroke, Connecting Rod, Crankshaft Arm, Crank Angle, Intake and Exhaust Valves
Identify and Calculate Engine Performance Parameters: Power, Torque, Efficiency, Mean Effective Pressure, Volumetric Efficiency, Specific Fuel Consumption
Perform Engine Kinematics Calculations such as the instantaneous Piston Speed
Evaluate the performance of heat engine cycles for which the working fluid remains a gas throughout the entire cycle
Develop simplifying assumptions applicable to engines
Solve problems based on the Otto, Diesel, Dual and Miller cycles
Analyze Cycles based on important parameters: Efficiency vs compression ratio, imep vs compression ratio and engine load and more
Compare Otto, Diesel and Miller cycles at various operating conditions
Learn how to draw P-V and T-S diagrams for each cycle
Perform a complete analysis for an Ideal Four Stroke Engine Cycle
Model the Intake and Exhaust Strokes and Evaluate the effect of residual fraction on cycle efficiency

Course content

4 sections • 51 lectures • 9h 15m total length

How Car Engine Works3:54
Discover how internal combustion engines generate power through the four-stroke cycle. See how pistons, valves, camshafts, and the crankshaft convert air-fuel expansion into rotational power.
Two-Stroke Cycle5:04
Explore how a two-stroke engine completes a cycle in one revolution, detailing exhaust blowdown, crankcase scavenging, transfer port flow, induction, compression, and spark ignition.
Engine Geometry10:46
Explore engine geometry parameters—bore, connecting rod length, crankshaft arm, and theta—and how they set piston motion between tdc and bdc, volumes, stroke, clearance volume, displacement, and mean piston speed.
Power, Torque and Efficiency13:38
Define brake power as the crankshaft power from torque and angular velocity. Compare it to indicated power in the combustion chamber and summarize four-stroke and two-stroke cycles, losses, and efficiency.
Mean Effective Pressure9:52
Define mean effective pressure as the work per unit displacement volume and explore indicated, brake, and friction mean effective pressures across four-stroke and two-stroke engines.
The Volumetric Efficiency5:44
Define volumetric efficiency as the ratio of actual air mass inducted to the ideal mass for displacement, reflecting intake manifold density and how restrictions reduce mass in a four-stroke engine.
The Brake Specific Fuel Consumption (bsfc)3:24
Examine brake specific fuel consumption (bsfc), the fuel flow per brake power, and why lower bsfc indicates better engine efficiency, alongside brake thermal efficiency and heat of combustion.
Example 15:07
Analyze a four-stroke 2.5-liter engine on a dynamometer at 2500 rpm to calculate brake power and mass air flow using volumetric efficiency and the ideal gas law.
Example 210:27
Analyze a six-cylinder, four-stroke engine at 75 kW with 12 bar brake mean effective pressure and 300 g/kWh bsfc; compute displacement and bore, and estimate 27% brake thermal efficiency.
Engine Kinematics9:12
Derive the instantaneous cylinder volume as a function of crank angle, linking clearance and displacement, then present the dimensionless volume and piston speed under angular velocity.
Example 310:12
Examine a three-liter spark-ignition six-cylinder engine at 3600 rpm, deriving bore, stroke, displacement, clearance volume, compression ratio, with end-of-combustion volume and constant-volume combustion.
Example 411:27
Analyze a 3-liter, six-cylinder engine on a dynamometer to compute brake and indicated power, mechanical efficiency, and brake and indicated mean effective pressures, illustrating friction losses.

Introduction: The Air-Standard Cycle7:27
Introduce the air-standard cycle for internal combustion engines, treating the working fluid as air in a closed loop. Explain the main assumptions: heat addition, heat rejection, and cold air standard.
The Otto Cycle: Constant Volume Heat Addition Cycle11:35
Compare the actual spark ignition engine cycle, highlighting constant volume heat addition and exhaust blowdown under air standard assumptions.
Thermodynamic Analysis of the Otto Cycle19:46
Analyze the Otto cycle thermodynamics with an ideal gas model, outlining the 1–4 states, constant-volume heat addition/rejection, and efficiency and indicated mean effective pressure.
Otto Cycle: The Indicated Thermal Efficiency13:52
Explore the Otto cycle's indicated thermal efficiency, showing how increasing compression ratio boosts efficiency while risking auto ignition and detonation, with practical limits around compression ratios of 6 to 10.
Otto Cycle: The Indicated Mean Effective Pressure9:14
Explore the Otto cycle and the indicated mean effective pressure, showing how imep relates to dimensionless heat input and compression ratio, with dimensionless forms and practical plotting.
Example 516:26
Analyze the auto cycle of a gas engine with a 200 mm bore and 250 mm stroke, calculate state points, compression ratio, efficiency, work, imep, and indicated power.
Example 632:18
Explore the auto cycle of a four-cylinder 2.5 liter spark-ignition engine, covering compression ratio 8.6, air–fuel ratio 15, isooctane fuel, heat of combustion, and residual gases, with a thermodynamic analysis.
The Diesel Cycle: Constant Pressure Heat Addition Cycle12:49
Explore the diesel cycle: compression ignition with air-only induction, high compression ratios, and fuel injection at top center, yielding constant pressure heat addition and later constant volume heat rejection.
Thermodynamic Analysis of the Diesel Cycle11:40
Explore the diesel cycle's thermodynamic analysis, detailing the 1-2 isentropic compression, 2-3 constant-pressure heat addition, 3-4 isentropic expansion, and 4-1 constant-volume heat rejection, with cutoff ratio beta concepts.
Diesel Cycle: The Indicated Thermal Efficiency17:02
Derive the diesel cycle's indicated thermal efficiency from heat input and rejection, relate it to cutoff and compression ratios, and compare with the auto cycle's indicator efficiency under load.
Plot of Indicated Thermal Efficiency of Diesel Cycle10:27
Explore how the diesel cycle's indicated thermal efficiency varies with compression ratio, calculate cutoff effects, and compare against the Otto cycle using an Excel plot.
Diesel Cycle: The Indicated Mean Effective Pressure11:09
Analyze the diesel cycle's indicated mean effective pressure (imep) as a function of compression ratio, cutoff, and dimensionless heat input, and compare it with the Otto cycle.
Example 718:06
Analyze an air-standard ic engine cycle with a 16:1 compression ratio and an 8% cutoff to determine state properties, work, efficiency, and indicated mean effective pressure.
Example 810:00
Compute the cutoff ratio and indicated efficiency for circuit example by solving the derived relation with P7 bar, P1 bar, and gamma 1.4; betar ≈ 2.223 and efficiency ≈ 55.5%.
Example 96:43
Compute the indicated thermal efficiency of a da cycle with air–fuel ratio 30 and compression ratio 16, yielding a cutoff ~2.48 and efficiency ~59%.
Example 106:29
Compute the compression ratio from P1 and P2, determine the expansion and cutoff ratios, and calculate the indicated thermal efficiency and indicated mean effective pressure.
Thermodynamic Analysis of the Dual Cycle10:07
Explore the dual cycle model for combustion in modern compression-ignition engines, showing heat addition at constant volume and constant pressure, and deriving relationships between state variables.
Dual Cycle: The Indicated Thermal Efficiency16:20
Derives the indicated thermal efficiency of the dual cycle, expressing it in terms of alpha and beta, and links heat addition modes to diesel and Otto limits.
Plot of Indicated Thermal Efficiency of Dual Cycle7:16
Plot the indicated thermal efficiency of the dual cycle and compare it with the Otto cycle, noting how alpha and remaining heat added at constant pressure vary with compression ratio.
Dual Cycle: The Indicated Mean Effective Pressure2:44
Plot and compare the indicated mean effective pressure of the dual cycle with auto and diesel cycles, showing imep ranking auto > dual > diesel at the same compression ratio.
Cycles Comparison: For the Same Compression Ratio and Heat Addition13:35
Compare the indicator thermal efficiency of auto, dual, and diesel cycles at the same compression ratio and heat addition using Peevey NTSA diagrams; auto is most efficient, diesel least.
Cycles Comparison: For the Same Compression Ratio and Heat Rejected7:18
Compare Otto, Diesel, and dual cycles at the same compression ratio and heat rejection using PV and TS diagrams, where heat rejection equals the area under the curve.
Cycles Comparison: For the Same Max Pressure, Max Temperature and Heat Rejected9:04
This lecture compares the auto, diesel, and dual cycles at equal max pressure, temperature, and heat rejection, showing diesel cycle yields the highest thermal efficiency due to higher compression ratios.
Cycles Comparison: For the Same Maximum Pressure and Heat Input8:13
Compare the Otto, Diesel, and dual cycles for the same maximum pressure and heat input, noting entropic compression and constant pressure heat addition, with Diesel highest, then dual, then Otto.
Cycles Comparison: For the Same Maximum Pressure and Work Output13:08
Compare three cycles with the same maximum pressure and work output using PV diagrams; conclude the dual cycle has the highest efficiency, followed by diesel and Otto.
Example 1111:23
Explore a dual cycle engine example with a compression ratio of 15, maximum pressure 60 bar, and state-point calculations to derive the indicated mean effective pressure and efficiency.
Example 128:55
Compute the dual cycle state temperatures for a compression ratio of 12 and cutoff 1.615, with a maximum pressure of 52.17 bar and p1 of 1 bar.
The Miller Cycle25:29
Explore the Miller cycle, with wide-open throttle and early inlet valve closing, where only a portion of displacement is inducted, reducing compression work and enabling greater expansion for improved efficiency.
Indicated Thermal Efficiency: Miller vs Otto8:04
Compare the indicated thermal efficiency of Miller and Otto cycles. Demonstrate how the Miller cycle achieves a higher expansion ratio and thus greater efficiency at the same compression ratio.
Indicated Mean Effective Pressure: Miller vs Otto5:00
This lecture compares the indicated mean effective pressure of Miller and Otto cycles, showing the auto cycle yields higher imep and how higher expansion ratio lowers the Miller-to-auto imep ratio.
Example 1315:34
Explore the wide-open throttle Miller circuit with early valve closing, compression ratio 8, expansion ratio 10, and isooctane fuel, calculating state points and Miller efficiency.

Introduction21:06
Explore how intake and exhaust pressures define throttled, wide-open, and supercharged IC engine cycles, and analyze pumping and indicated work affecting net performance.
Exhaust Stroke12:26
Explore the exhaust stroke, including constant volume blowdown, gas displacement by the piston, exhaust pressure, and residual gas fraction's dependence on compression ratio and volumetric efficiency.
Volumetric Efficiency Relation to Residual Fraction3:46
explains how volumetric efficiency depends on residual fraction, deriving it from inductive mass and intake density, and shows that higher residuals lower density and inductive mass.
Intake Stroke9:50
Analyze the intake stroke by deriving the total cylinder mass from inducted and residual gases and express the temperature as a function of residual fraction, intake pressure, and temperatures.
Ideal Four Stroke Otto Cycle Analysis4:30
An ideal four-stroke otto cycle analysis outlines the intake and compression strokes, constant-volume heat addition, isentropic expansion, isotropic blowdown, and a constant-pressure adiabatic exhaust stroke.
Example 1415:19
analyze a diesel engine cycle with compression ratio 22, intake temperature 300 kelvin, throttle conditions, and residual gas to derive indicated and net indicated thermal efficiency and pumping work.
Example 1512:37
Explore the auto cycle of internal combustion engines by deriving state temperatures and pressures, residual fraction, and thermal and volumetric efficiencies using solver-based iterations in Excel.

Requirements

A Strong Background in Engineering Thermodynamics is Required.
Knowing How to Use Microsoft Excel is Also Required.

Description

The internal combustion (IC) engine is a heat engine that converts chemical energy in a fuel into mechanical energy, usually made available on a rotating output shaft. Chemical energy of the fuel is first converted to thermal energy by means of combustion or oxidation with air inside the engine. This thermal energy raises the temperature and pressure of the gases within the engine, and the high-pressure gas then expands against the mechanical mechanisms of the engine. This expansion is converted by the mechanical linkages of the engine to a rotating crankshaft, which is the output of the engine.

The main focus of this course is on the application of the engineering sciences, especially the thermal sciences, to internal combustion engines. The goals of the course are to familiarize the student with engine nomenclature, describe how internal combustion engines work, and provide insight into how engine performance can be modeled and analyzed.

In this course, we discuss the engineering parameters that are used to characterize the overall performance of internal combustion engines. Major engine cycles are covered such as Otto, Diesel, Dual and Miller cycles. The following lectures will apply the principles of thermodynamics to determine temperatures and pressures throughout an engine cycle, in addition to important engine performance parameters such as: Indicated Thermal Efficiency and the Indicated Mean Effective Pressure. Also we investigate the dependence of engine performance on engine compression ratio and engine load.

An aspect upon which we have put considerable emphasis is the process of constructing idealized models to represent actual physical situations in an engine. Throughout the course, we will calculate the values of the various thermal and mechanical parameters that characterize internal combustion engine operation.

My goal in this course is to help students acquire a solid theoretical background of internal combustion engines. Solved numerical examples are used extensively in this course to help students understand how theory is applied to analyze practical applications.

Who this course is for:

Engineering students interested to learn about engines

Fundamentals of Internal Combustion Engines - IC Engines

What you'll learn

Explore related topics

Course content

Introduction12 lectures • 1hr 39min

Heat Engine Cycles31 lectures • 6hr 17min

Ideal Four Stroke Process and Residual Fraction7 lectures • 1hr 20min

Exercise Files1 lecture • 1min

Requirements

Description

Who this course is for: