NOC:Muffler Acoustics – Application to Automotive Exhaust Noise Control

Media Storage Type : 32 GB USB Stick

NPTEL Subject Matter Expert : Prof. Akhilesh Mimani

NPTEL Co-ordinating Institute : IIT Kanpur

NPTEL Lecture Count : 47

NPTEL Course Size : 5.9 GB

NPTEL PDF Text Transcription : Available and Included

NPTEL Subtitle Transcription : Available and Included (SRT)

Lecture Titles:

Lecture 1 - Introduction to Acoustic Wave Propagation
Lecture 2 - D'Alemberts's solution and 1-D Continuity equation
Lecture 3 - Muffler Acoustics-Application to Automotive Exhaust Noise Control
Lecture 4 - Linearization of governing equations, and Development of 1-D Acoustic wave and Helmholtz equation
Lecture 5 - Solution of 1-D Helmholtz equation: Propagation in 1-D ducts/pipes
Lecture 6 - 1-D Acoustic Wave Equation in Ducts Carrying Uniform Mean Flow: Derivation
Lecture 7 - 1-D Acoustic Wave Equation in Ducts Carrying Uniform Mean Flow: Solution
Lecture 8 - 3-D Acoustic Wave Equation in Rectangular and Circular Waveguides: Derivation, Modal Solution and Concept of Cut-on Frequency
Lecture 9 - Sound Pressure Level, Intensity Level and Sound Power Level
Lecture 10 - Acoustic Impedance and Reflection Coefficient
Lecture 11 - Lumped System Analysis: Inertance and Compliance
Lecture 12 - Lumped Analysis of a Uniform Pipe Closed/Open at an End, Concept of End Correction
Lecture 13 - Helmholtz Resonator, Electro-Acoustic Analogy and Layout of a typical engine exhaust system
Lecture 14 - Muffler Performance Measures: Insertion Loss
Lecture 15 - Muffler Performance Measures: Transmission Loss and Level Difference
Lecture 16 - Lumpted Analysis of a Tube, Simple Area Discontinuity and Transfer Matrices
Lecture 17 - Sudden area Discontinuity (Continued...)
Lecture 18 - Simple Expansion Chamber Analysis Using Transfer Matrix Method
Lecture 19 - Transmission Loss (TL) Graph for a Simple Expansion Muffler (MATLAB)
Lecture 20 - Extended-Inlet and Extended-Outlet Muffler Analysis
Lecture 21 - Extended-Inlet and Extended-Outlet Muffler Analysis (Continued...)
Lecture 22 - TL Analysis of Extended-Inlet and Extended-Outlet Muffler (MATLAB)
Lecture 23 - TL Analysis of Side-Inlet and Side-Outlet Muffler Using Transfer Matrix Method
Lecture 24 - Wave Propagation in Gradually Varying Area Ducts: Webster’s Horn Equation
Lecture 25 - Webster’s Horn Equation (Continued...) and Exponential Ducts
Lecture 26 - Solution of Webster’s Horn Equation for Conical Ducts
Lecture 27 - TL analysis for Conical Muffler Configurations (MATLAB)
Lecture 28 - Segmentation Approach for Analysing Gradually Varying Area Ducts (MATLAB)
Lecture 29 - Acoustic Intensity (Energy Flux) in a Pipe with Mean Flow, and Transmission Loss Expression
Lecture 30 - Aeroacoustic State Variables Transfer Matrix for a Tubular Element (Uniform Pipe)
Lecture 31 - Transfer Matrix for Extended-Inlet and Outlet Element and Use of Perforated Elements in Commercial Mufflers
Lecture 32 - Two-interacting Duct Configurations: Development of Equations and Concentric Tube Resonators
Lecture 33 - Concentric Tube Resonator: Partially Perforated Pipe or Airway (MATLAB)
Lecture 34 - Review of Perforate Impedance Expressions
Lecture 35 - MATLAB Demonstration for Fully and Partially Perforated CTR
Lecture 36 - Cross-Flow elements: Setting-up the Equations
Lecture 37 - Cross-Flow elements: MATLAB Demonstration for Simple Configurations
Lecture 38 - Plug Mufflers, Three-pass Perforated Element Muffler (Commercial Configurations) - MATLAB
Lecture 39 - Multiply-Connected Mufflers: HQ Tubes
Lecture 40 - TL Analysis of HQ Tubes (MATLAB): Network Analysis and Analytical Formula
Lecture 41 - Transmission Loss in terms of Scattering and Impedance Matrix Parameters
Lecture 42 - Rectangular Chamber Muffler: Characterization and TL Analysis using 3-D Piston-driven Model
Lecture 43 - Circular Chambers: Characterization and TL Analysis Using 3-D Piston-driven Model
Lecture 44 - Analytical Mode-Matching for Extended-Inlet and Outlet Muffler: Setting-up of the Equations
Lecture 45 - MATLAB Demonstration for Transmission Loss Calculations
Lecture 46 - Dissipative Mufflers (Lined Circular duct) - A Brief Discussion
Lecture 47 - Summary of the Topics Covered in This Course, Topics to be Covered in a Future Course