ME711A

Computational Turbulence

Credits:

  

 

3-0-0-9
 

Course Content:

Introduction: Examples of turbulent flow, modeling and their applications, Review of fluid mechanics: Mass, momentum and energy equations, boundary layer theory; Theory of turbulent flow: Introduction and statistical description of turbulence, scales of turbulence, energy cascade, Reynolds Equations (SRANS and Unsteady RANS), Reynolds Stress (RS) Equations and closure problems, Turbulent kinetic energy equations, wall bounded, and free-shear turbulent flows, Dynamics of turbulence, coherent and incoherent structures; Review of computational method: Aspects of Finite Difference Equation (FDE) (stability, convergence, order of accuracy, truncation error etc. using modified equations), FDM Solution of Incompressible Viscous Flows (SIMPLE and MAC); Turbulence modeling and simulations: Direct numerical simulation: Accuracy (higher order discretization, scales etc.) and Stability; Large Eddy Simulation: LES filtering, properties of filtering, Explicit and implicit filtering, LES equations, Smagorinsky model and their variants (DSM, SISM), Grid independent LES, Applications to free-shear and wall-bounded flows; Steady/Unsteady Reynolds-averaged Navier–Stokes equations (RANS and URANS) model: (a) Zero equation model, (b) One- and (c) Two-equation models (k-ε, k-ω models), closure models, application for free-shear and wall-bounded flows, range of applicability; Reynolds Stress based modeling and its applications; Probability Density Function (PDF) Modeling: Definitions, Brownian motion, Application to reacting flows (if time permits).

Lecturewise Breakup (Based on 40 lecture)


I. Introduction: [1 lecture]

  • Examples of turbulent flow, modeling and their applications.

II. Review of fluid mechanics: [2 lectures]

  • Mass, momentum and energy equations, boundary layer theory.

III. Theory of turbulent flow: [13 lectures]

  • Introduction and statistical description of turbulence, scales of turbulence, energy cascade.

  • Reynolds Equations (SRANS and Unsteady RANS), Reynolds Stress (RS) Equations and closure problems.

  • Turbulent kinetic energy equations, wall bounded, and free-shear turbulent flows.

  • Dynamics of turbulence, coherent and incoherent structures.

IV. Review of computational method: [5 lectures]

  • Aspects of Finite Difference Equation (FDE) (stability, convergence, order of accuracy, truncation error etc. using modified equations), FDM Solution of Incompressible Viscous Flows (SIMPLE and MAC).

V. Turbulence modeling and simulations: [20 lectures]

  • Direct numerical simulation: Accuracy (higher order discretization, scales etc.) and Stability.

  • Large eddy simulation: LES filtering, properties of filtering, Explicit and implicit filtering, LES equations, Smagorinsky model and their variants (DSM, SISM). Grid independent LES, Applications to free-shear and wall-bounded flows.

  • Steady/Unsteady Reynolds-averaged Navier–Stokes equations (RANS and URANS) model: (a) Zero equation model, (b) One- and (c) Two-equation models (k-ε, k-ω models), closure models, application for free-shear and wall-bounded flows, range of applicability.

  • Reynolds Stress based modeling and its applications.

  • Probability Density Function (PDF) Modeling: Definitions, Brownian motion, Application to reacting flows (if time permits).

References:

  1. Fluid Mechanics, F. M. White (7th Edition, McGraw Hill, 2011)

  2. Fluid Mechanics, P. K. Kundu, I. M. Cohen and David R. Dowling (5th Edition, Academic Press, 2012)

  3. Computational Techniques for Fluid Dynamics, Vol. 1 and Vol. 2, C. A. J. Fletcher, Springer Verlag

  4. Computational Fluid Flow and Heat Transfer, Eds. K. Muralidhar and T. Sundararajan, (Narosa Publishers, New Delhi, 2011).

  5. Turbulent Flows, Stephen B. Pope (Cambridge University Press, 2000).

  6. Turbulence Modeling for CFD, David C. Wilcox, (DCW Industries, Incorporated, 1994).

  7. Turbulent Flow, Fundamentals, Experiments and Modeling, Editors: G. Biswas and V. Eswaran, (Narosa Publishing House, New Delhi, 2002).
 

ME359A

Internal Combustion Engines

Credits:

  

 

3-0-0-9
 

Course Content:

Introduction to Internal Combustion Engines, Basic Introduction to SI & CI engine, Air Standard Cycles and their Analysis, Fuel-Air Cycles and their analysis, Conventional fuels & Alternative fuels, Fossil fuels: Refining & Properties, Analysis of fossil fuels, Fundamentals of SI & CI engine, Engine Ignition System, Engine cooling system, Engine Friction and Lubrication, Supercharging and Turbocharging, Carburetor and Fuel Injection Systems, Fuel Injection in SI engine, Combustion in CI Engines, Knocking in SI and CI engine, Combustion Chamber Design of SI and CI engines, Wankel Engine, Engine Performance parameters, Measurement and Testing, Pollution from SI and CI engines, Emission Measurement Instruments, gasoline Direct Injection Engine (if time permits), Homogeneous charge compression ignition (HCCI) Engine.

Lecturewise Breakup (Based on 40 lecture)


I. Introduction:

  • Heat Engine and Their Classification, IC engine components, Engine Terminology, Basic working Principle, Basic Introduction to SI and CI engine, Engine Performance Parameters. [2]

II. Thermodynamic Cycles:

  • Ideal air-standard cycles, Otto Cycle, Diesel Cycle, Limited Pressure Cycle, Deviation of Actual Cycle from Air Standard Cycle, Considerations in Fuel-Air cycles, Effect of variables on engine performance, Actual Engine Cycles, Losses in Actual engine cycle. [3]

III. Conventional fuels & Alternative fuels:

  • Energy Scenario, Transport Fuel, Petroleum Based Liquid Fuel and Their Characteristics, Alternative Fuel Factors, Methanol, CNG, LPG, LNG, DME, Hydrogen, Biofuels, Viable Option for India. [3]

IV. Fossil fuels –Refining, Properties and Analysis:

  • Fossil Fuel Formation, various Sources, Drilling Arrangements, Crude Oil Composition, Petroleum Refining, Refined Petroleum Products, Fuels Properties such as Calorific Value, Flash Point, Pour Point, Octane and Cetane Number, Knocking Characteristics, Volatility, Important Qualities of SI and CI engine Fuels, Rating of SI and CI engine Fuels. [4]

V. Thermo-Chemistry of Fuel-air Mixture:

  • Stoichiometric Combustion of Fuels, Heat of Reaction, Adiabatic Flame Temperature. [2]

VI. Combustion in SI and CI Engines:

  • Examples of CI and SI engine, Engine Performance, Combustion in SI engines, Ignition Process and Limit, Spark Plug, Spark and Flame Propagation, Stages of Combustion in SI engines, Flame Front Propagation, Effects of Engine variables on Ignition Lag, Factors Influencing the Flame Speed, Combustion in CI engine, Stages of CI engine combustion. Knocking in SI and CI engine, Effect of Engine Variables on Knock, Comparison of knocking in SI & CI engine, factors affecting Detonations. [4]

VII. Engine Ignition System:

  • Energy Requirement for Ignition, Different Ignition System and Working, Component of battery Ignition System, Requirement of Spark Plugs, Design of Spark Plug, Magneto Ignition System, Transistorized Coil Ignition, Capacitive Discharge Ignition, Firing Order, Ignition Timing. [2]

VIII. Engine cooling system, Engine Friction and Lubrication:

  • Variation of Gas Temperature, Piston and Cylinder Temperature Variation, Parametric Affecting Engine Heat Transfer, Power Requirement for cooling, Types of Cooling System, Diagnosis of Cooling Systems Problems, Engine Friction and Types, Factors affecting Mechanical Friction, Lubrication and its mechanism, Different Lubrication System (Mist, Wet Sump, Dry Sump). Properties of Lubricants, Additive of Lubricants. [3]

IX. Supercharging and Turbocharging:

  • Boosting the Engine, Supercharging, Different types of supercharger, Characteristics of a centrifugal compressor, Effect of supercharging on performance of the engine, Working of Turbocharger, Turbolag, Overloading of Engine by Turbocharger, Different types of Turbocharger, Turbocharger and Supercharger Configurations, Advantages of Supercharger and turbocharger. [3]

X. Fuel Injection System:

  • Carburetor, Working of Carburetor, Components of a carburetor, Types of Carburetors, Electronic Fuel in Injection (EFI) System, Components of an EFI system, Fuel Injectors, Types of Injection, Electronic control of engines, Requirement of Diesel Injection System, Types of Injection system for CI engine, Fuel Pump, Nozzles. [4]

XI. Combustion Chamber Design:

  • Combustion chambers in SI engines, Important Factors Considered in Combustion Chamber Design, Combustion Chambers in CI engines, Direct Injection and Indirect Injection Chamber, Different Types of Swirl, Direct Injection Volumetric Combustion Chamber Illustrating Phases of Combustion. [3]

XII. Wankel Engine:

  • Introduction, Development of Wankel Engine, Components of a Wankel Engine, Working of Wankel Engine, Features of Rotary Wankel Engine, Lubrication in Wankel Rotary Engine, Exhaust Emission Characteristics of Wankel Engine, Reciprocating Engine Vs. Rotary Wankel engine, Advantages and Disadvantages of Wankel engine, Application of Wankel Engine. [2]

XIII. Engine Performance Parameters:

  • Fuel Power, Indicated Power, Brake Power, Efficiency, Performance of SI Engines, Engine performance characteristics for SI engine, Performance of CI Engines, Variables affecting performance characteristics, Methods of improving engine performance, Performance Maps. [2]

XIV. Measurement and Testing:

  • Measurement of Speed, Fuel Consumption Measurement, Volumetric type flowmeters, Measurement of Air consumption, Measurement of Brake Power, Types of Dynamometer, Measurement of Frictional Power, Measurement of Indicated Power. [1]

XV. Pollution From Engines:

  • Exhaust Emissions, Effect of Various Parameter on Exhaust Emissions, Exhaust Emissions from SI Engines, Gasoline Engine Emission Control, Diesel Engine Exhaust Emissions, Comparison of Diesel and Gasoline Emissions. [1]

XVI. Exhaust Gas Emission Analysis:

  • Emission measurement, Non-Dispersive Infrared Spectroscopy, Working of NDIR System, Flame Ionization Detector, Schematic and Working of FID system, Chemiluminescence Analyzer, Smoke opacimeters. [1]

References:

  1. IC Engine Fundamentals: John B. Heywood, Mc Graw Hill

  2. Fundamentals of IC Engines: P. W. Gill and James Smith, Oxford IBH

  3. Introduction to Internal Combustion Engines: Richard Stone, SAE Inc., 1999

  4. IC Engines (Combustion and Emissions): B. P. Pundir, Narosa Publications

  5. IC Engine Fundamentals: V. Ganesan, Tata Mc Graw Hill

  6. Thermodynamics: Cengel and Boles, Tata McGraw Hill
 

ME757A

Dynamics of Rotating Machinary

Credits:

  

 

3L-0T-0L-0D [9 Credits]
 

Course Contents:


Rotor-bearing interaction. Flexural vibration, critical speeds of shafts, Effects of anisotropic bearings, unbalanced response of an assymetric shaft. Gyroscopic effects. Aerodynamic effects. Equivalent discrete system. Geared and branched systems. Fluid film bearings: Steady state characteristics of bearings. Rigid and flexible rotor balancing. Measurement techniques.

Lecturewise Breakup:(number of 55 mins lectures in brackets)

Introduction [1]
Review of Vibrations [3]
Modelling and Bending Critical Speeds of Rotors [2]
Whirling Phenomenon
Rigid rotors in rigid supports
Flexible rotors in rigid supports
Flexible rotors in flexible supports
Rolling Element Bearings [2]
Contact Forces
Deformations, Stiffness and Damping
Hydrodynamic Bearings [4]
Mechanism of Pressure Development in a Fluid Film
Reynold's Equation
Steady State Solution for Short Bearing
Dynamically loaded bearings and stiffness and damping coefficients
Squeeze Film Bearing
Squeeze Film Bearing and Orbital Motion
Matrix Methods [4]
Field and Point Matrices
Out of balance response of rotors with rigid end supports
Rotors with overhangs
Unbalance response by FEM
Torsional Vibration of Rotors [4]
Modelling and transfer matrix analysis for free vibrations
Variable Stiffness in Torsional Vibrations
Excitation torques and transient response
Branched and Geared Systems
Torsional vibrations in reciprocating machinery
Higher order effects and Stability [12]
Hill's Equation, Mathieu's Equation, Strutt Diagram
Routh Hurwitz criterion
Shafts with dissimilar moments of inertia
Effects of Gravity
Internal Hysteresis of Shafts
Rigid Rotor Instability
Instability of rotors mounted in fluid film bearings
Instability of flexible rotors
Instability due to negative cross-coupling
Instability in torsional vibrations
Gyroscopic Effects
Rotor Balancing [4]
Classification of Rotors
Rigid rotor balancing
Flexible rotor balancing
Monitoring and Diagnosis [4]
Faults in rotating machinery
Instrumentation and Data Acquisition
Time and Frequency domain characteristics
Knowledge base and expert systems
  [40]

References:

  1. Mechanical Vibrations-JP Den Hartog-1956-070163898-McGraw-Hill

  2. A Handbook on Torsional Vibration-EJ Nestorides-1958-none-Cambridge University Press

  3. Flexural Vibrations Of Rotating Shafts-FM Dimentberg-1961-none-Butterworths

  4. Theory of Hydrodynamic Lubrication-O Pinkus, B Sternlicht-1961- -McGraw-Hill

  5. Some Problems Of Rotor Dynamics-A Tondl-1965-0317262033 0608123781-Chapman & Hall

  6. Dynamic Stability Of Rotor-Bearing Systems-EJ Gunter-1966-NAS 1.21:113-NASA SP-113

  7. Critical Speeds and Response of Flexible Rotor Systems-R. L. Eshleman-1972- -ASME

  8. Analytical Methods In Rotor Dynamics-AD Dimarogonas, SA Paipetis-1983-0853341990-Applied Science

  9. Rotor Dynamics-JS Rao-1983-0470274484-Halsted Press

  10. Balancing Of Rigid And Flexible Rotors-Neville F. Rieger-1986-85600519-Shock and Vibration Information Center

  11. Rotordynamics Of Turbomachinery-JM Vance-1988-0471802581-Wiley

  12. Dynamics of Rotor Bearing Systems-MJ Goodwin-1989-0046210326-Thomson Learning

  13. Journal Bearing Data Book-T Someya-1989-354017074X 038717074X-Springer-Verlag

  14. Turbomachinery Rotordynamics-Phenomena, Modeling And Analysis-Dara Childs-1993-047153840X-Wiley

  15. Dynamics Of Rotors And Foundations-E Kramer-1993-3540557253(0387557253-Springer-Verlag)

  16. Rotordynamics Prediction In Engineering-M Lalanne, G Ferraris-1998-0471972886-Wiley

  17. Handbook Of Rotordynamics-FF Ehrich-1998-0070193304-McGraw-Hill

  18. Fundamentals of Rotating Machinery Diagnostics-Donald E Bently, Charles Hatch-2002-0971408106-Bentley Pressurized Bearing Press

  19. Rotor Dynamics-Agnes Muszynska-2005-0824723996-Taylor & Francis

  20. Magnetic Bearings Theory, Design, and Application to Rotating Machinery-Gerhard Schweitzer and Eric H. Maslen, editors-2009-3642004962-Springer
 

ME778

Engineering Acoustics and Its Control

Credits:

  

 

9
 

Course Contents:

Introduction to wave phenomenon, Acoustic variables, Sound speed, Concepts of wavefronts, Progressive and standing waves, Noise control strategies: Sound source modification, Control of transmission path, modification of receiver path, Airborne and Structure-borne noise, 1-D Acoustic wave equation, Helmholtz equation, Boundary conditions, Resonance frequencies of a closed/open tube, Sound Pressure Level, Sound Intensity Level and Sound Power Level, A-weighting, Simple (monopole), dipoles, lateral and longitudinal quadrupole sources, Directivity, Near- and far-field, Piston in a baffle, Reflection and transmission of normally incident wavefronts, Outdoor sound propagation: Analysis of barriers, Wave propagation in waveguides: Muffler analysis, General noise control methods, Noise estimates for typical engineering applications


Lecturewise breakup: (number of 50 minutes lectures indicated in brackets)


Introduction to wave phenomenon:

Forward and backward propagating pulse, Sound or wave speed

[1]


Development of one-dimensional acoustic wave equation:

Derivation of continuity and momentum equation based on control volume approach, Isentropic (State) relationship, Acoustic state variables: perturbation pressure, density and velocity, Planar wavefronts in an infinite waveguide, D-Alembert’s solution, Helmholtz equation (frequency-domain), Backward and Forward propagating waves, Boundary conditions: rigid, open and impedance conditions, Resonance frequencies of an open or a closed duct, 1- D acoustic waves in an infinite duct with a uniform moving medium

[5]


Acoustic Terminology (Measurement Units):

Acoustic pressure, velocity, density (revise), Impedance, Acoustic power expression, Sound Pressure Level (SPL), Sound Intensity Level, Sound Power Level, Spectrum and Frequency bands, Z-, A- and Cweighting

[3]


Noise Control Strategy (Introduciton concepts):

Sound source modification, Control of transmission path, Modification of the receiver path, Airborne and Structure-borne noise

[1]


Reflection and Transmission of Normally Incident Plane waves:

Reflection and Transmission coefficients, Reflection of plane wave at infinite plane boundary, special cases of rigid-wall (termination), pressure release, matched-impedance conditions, general resistive or impedance termination, Reflection at finite interface: change in cross-sectional area, RayleighSommerfeld radiation formulation

[4]


Canonical Acoustic Sources:

Simple (monopole), dipoles, lateral and longitudinal quadrupole, Array of N sources, continuous line array of sources, near- and far-field spectrum, Source directivity, Real-world examples (Approximations) for outdoor sound propagation such as barriers, Piston in an infinite baffle and related cases

[5]


Wave propagation in waveguides:

Waveguides of rectangular, circular cylindrical geometry: Solution of Helmholtz equation in Cartesian and cylindrical polar co-ordinates, normal (rigid-wall) modes and natural frequencies, cut-on and cut-off frequencies, evanescent modes, Gradually varying area ducts: Webster’s horn equation, Ducts with compliant walls

[6]


Mufflers (Silencers) for controlling emissions from Internal Combustion Engines:

What is it? Types (classification): Reactive and Dissipative Mufflers, Measures of Muffler performance, Lumped element analysis and Electro-acoustic analogies, Impedance at the duct termination, Endcorrection, Reactive mufflers (1-D or plane wave approach): Sudden-area discontinuity, Simple expansion chamber (SEC), Extended-inlet and extended-outlet (quarter-wave) resonator types, straightthrough silencers with perforated airway (pipes), plug-muffler, flow-reversal configurations, mufflers with multiple propagation paths, side-branch resonator, Aeroacoustic state variables and analysis, Perforated mufflers: Acoustic impedance of perforates, Concentric Tube Resonator, Cross-flow expansion and contraction elements, conical-concentric tube resonator (Matrizant analysis), Perforated elements with three-interacting ducts, Commercially used perforated duct mufflers, 3-D analytical modelling for muffler performance evaluation, Dissipative mufflers: Lined duct silencers, Introduction to numerical approaches in muffler modelling

[15]


Noise Control Strategies:

Control of noise at source: Select a quieter machine, lossy materials, quieter processes or tools, Reduce radiation efficiency, Maintenance and health-monitoring, Estimation and Control of Compressor, Fan and Blower noise, packaged chillers and cooling towers, pump noise and jet noise

[1]


Suggested Texts:

  • Fundamentals of Physical Acoustics, David T. Blackstock, John Wiley (2000)

  • Fundamentals of Acoustics, Lawrence E. Kinsler et al., John Wiley and Sons – can buy this one also (Indian edition available).

  • Engineering Noise Control, David A. Bies & Colin H. Hansen, CRC Press 2009

  • Engineering Principles of Acoustics, Noise and Vibration Control, Douglas D. Reynolds (1981), Allyn and Bacon

  • Theoretical Acoustics, Philip M. Morse and Uno Ingard, Princeton University Press


Reference Texts(Waveguide and Silencer analysis):

  • Acoustics of Ducts an Mufflers, M. L. Munjal, Wiley, 2nd Edition 2014

  • Acoustic Analysis and Design of Short Elliptical End-chamber Mufflers, A. Mimani, Springer 2021