Course

Elective Streams General Electives

Lab Content 45 hours

1. Sound Power evaluation using SPL measurements- ISO 3744
2. Motor SPL measurement as per SAE
3. Modal Testing and analysis
4. Signal Analysis using FFT
5. Demonstration of inverse square law
6. Demonstration of the effect of sound absorbing and insulating materials
7. Noise source identification by masking method
8. Motor vehicle pass-by noise- IS 3028/ISO 362
9. Motor vehicle Stationary noise (tail pipe noise) – ISO 10399
10. Sound Quality analysis – Jury Rating, Metrics and its correlation
11. Vibration measurement and Modal analysis

Unit 1

Introduction to Automotive NVH-Fundamentals of vibrations –Vibration of Single degree of freedom, Multi degrees of freedom – Vehicle vibration measurement and analysis Fundamentals of acoustics, Vehicle noise measurement, Noise Standards, Types of Signals, Signal conditioning and processing, Data Acquisition Systems, Analysis and presentation of data Ride Comfort – Sound Quality and psychoacoustics –Sound Quality Metrics, Subjective–objective correlation –Squeak and Rattle-Vibration isolation and Transmission.

Unit 2

Signal Analysis: Fourier series – Fourier Integrals –- Discrete Fourier Transforms – Fourier and Laplace Transforms – Filters – Windowing – Time Sampling and Aliasing – Random signal processing and analysis -Theory of modal analysis – Methods for performing modal analysis, Modal analysis of components, systems and vehicles Vehicle NVH refinement –Vehicle Development process – Target setting and Benchmarking. (10 hours)

Unit 3

Refinement of Power train systems, Chassis and Suspension and Body –Vibro-acoustics – Aerodynamic noise and its refinement–Aeroacoustics Simulation methods in Automotive NVH – FEM, BEM, MBD, CFD, TPA, SEA, Vibro and Aeroacoustics, Cross functional optimization–Acoustic shielding and sound packages – Acoustic materials and their characterization – Active and semi-active noise control and their control systems and applications-Special issues related to EHV NVH .

Course Objectives

1. To inculcate measurement and analysis techniques for vehicle noise and vibration
2. To familiarise with the application of NVH refinement in vehicles and their systems
3. To introduce advanced techniques in reduction of NVH
4. Enable to use simulation tools to analyse the signals for reducing

Course Outcomes

CO-PO Mapping

Skills acquired

Measurement and analysis of Vehicle Noise and vibration, Signal Processing and analysis including Random signals, modal analysis, vibration and noise reduction techniques.

Text Books / References

1. Xu Wang, “Vehicle Noise and Vibration Refinement”, CRC Press Publication,
2. M. KrodkiewskI, “Mechanical Vibration” Univ of Melbourne, 2018
3. Kihong Shin and Joseph Hammond “Fundamentals of Signal Processing for Sound and Vibration Engineers”, Johe Wiley, 2021.
4. S.Rao, “ Mechanical Vibrations”, Prentice- Hall, 2011