Design, Analysis & Optimization of Muffler for Four Stroke Petrol Engine Motorcycle

Abstract

Objective: The exhaust pipe is subjected to several stresses, most of which are due to vibration. Particular attention should be given to gas forces which will induce vibration. These vibrations will then induce a fatigue life to the system. It is therefore necessary to study the fatigue behavior of the exhaust pipe by analyzing the vibration modes and the response of vibrations by its sources. Methods: The vibrations of silencer are affecting the performance of silencer and it is uncomfortable to operators. So, it is necessary to analyze the vibrations which would further help to minimize cracks, improving life and efficiency of silencer. the main goal of this project will be to design a new automobile exhaust piper muffler (silencer) is to increase the durability of its life. Decrease the weight, and reduce the manufacturing cost with efficient working condition. design, analyze the model using ANSYS workbench static structural and model analysis for vibration study. If muffler or silencer part impacts high vibrations, or stress then topology will be conducted to solve the high stress concentration and vibrational impacts.

Introduction

I. INTRODUCTION

One of the objectives when designing a new automobile exhaust pipe is to lengthen its durability period, which can be measured in terms of its life span and mileage. The exhaust pipe is subjected to several stresses, most of which are due to vibration. Particular attention should be given to gas forces which will induce vibration. These vibrations will then induce a fatigue life to the system. It is therefore necessary to study the fatigue behavior of the exhaust pipe by analyzing the vibration modes and the response of vibrations by its sources.

The vibration of a system involves the transfer of its potential energy to kinetic energy and of kinetic energy to potential energy, alternately. If the system is damped, some energy is dissipated in each cycle of vibration and must be replaced by an external source if a state of steady vibration is to be maintained.

A. Overview

The main goal of this project is to study the vibrational impact caused due to the vehicle moving on irregular road surface and also due to exhaust gas pressure variations in two-wheeler muffler. Mufflers is an important component in vehicle, without muffler or silencer one can’t assume an engine.

After expansion in the engine exhaust gas produced containing harmful gases is exhausted in a long hollow pipe called muffler at back side of the vehicle.

For time being these mufflers have been optimized in different shape, size, and material etc. the main goal of this project will be to design a new automobile exhaust piper muffler (silencer) is to increase the durability of its life. Decrease the weight, and reduce the manufacturing cost with efficient working condition.

In this project I’m going to design, analyze the model using ANSYS workbench static structural and model analysis for vibration study. If muffler or silencer part impacts high vibrations, or stress then topology will be conducted to solve the high stress concentration and vibrational impacts.

Vibrations are measured in 3 different phases which are classified as: Frequency, amplitude and Phase are the three major characteristics which are used to describe a oscillation in the part or component (or vibrations).

There are 3 types of Vibration:

• Free or Natural.
• Forced and.
• Damped Vibration.

1. Longitudinal Vibrations: In this, the particles of the shaft or disc move parallel to the axis of the shaft as shown in the above diagram. In this case, the shaft is elongated and shortened alternately thus executing the tensile and compressive stresses alternately on the shaft.
2. Transverse Vibrations: In this, the particles of the shaft or disc move perpendicular to the axis of the shaft as shown in the above diagram. Here the shaft is straight and bent alternatively and hence bending stresses are induced in the shaft.
3. Torsional Vibrations: In this, the particles of the shaft or disc move in a circle about axis of the shaft as shown in the above diagram. Here the shaft is twisted and untwisted alternatively and hence torsional shear stress is induced in the shaft.

B. Need for Analysis

The Automobile silencer under study belongs to a popular 2-Wheeler manufacturer in India with the rated HP of the engine. The exhaust gases coming out from engine are at very high speed and temperature. Silencer has to reduce noise, vibrations. While doing so it is subjected to thermal, vibration and fatigue failures which cause cracks. So, it is necessary to analyze the vibrations which would further help to pursue future projects to minimize cracks, improving life and efficiency of silencer.

B. Problem Statement

Vibrations are the real problem of machines they encounter almost in all components connected to dynamic constraint. Whenever a part or component undergoes or subjected to a periodic motion the part impacts to a vibration. Following are the causes of when vibration induces.

1. Unbalance: whenever vibration induces in a certain part, it disrupts the balance of it because of its higher tendency of frequency.
2. Resonance: it is an effect of collision or noise.
3. It effects in loosing of jointed parts, like nut & bolt loosening
4. Bearing damage: vibrations can damage the bearings by misaligning it.

For future esthetic condition high speed vehicles play a definable role, while a vehicle moves at a top speed on an irregular surface it under goes into vibrational impact caused due shock in road. This in term can result a muffler to fail due to high temperature exhaust has moving inside the silencer, also due to the road terrain. Muffler may undergo to failure or cracks or loosening from the engine manifold. To prevent this one must investigate the silencer under natural forces.

II. PROPOSED SYSTEM

A. Formulations

1)  Equilibrium Method

It is based on the principle that whenever a vibratory system is in equilibrium, the algebraic sum of forces and moments acting on it is zero recordings to D’Alembert’s Principle that the sum of inertia forces and external forces on a body in equilibrium must be zero.

IV. ACKNOWLEDGEMENTS

The author would like to thank following guides for his constant encouragement and able guidance.

Prof. R.R Kulkarni

Prof. Kedar Bhagwat

Siddhant Collage of Engineering, Sudumbare, Pune.

Conclusion

In this project the 1st iteration of the analysis has been done to check the vibrational frequency of the muffler using structural steel material and the maximum frequency obtained at mode 6 is 321.82 Hz. In 2nd iteration same boundary condition is used and simulation is solved, here the material has been changed from SS to aluminum & titanium, the maximum frequency developed was 323 Hz which is 1-2 Hz more compared to steel but due to its less density the aluminum has less weight. And for titanium the maximum frequency developed is 292.6 HZ which is lesser than all steel as well as aluminum. But the cost for titanium is more compared to another material. The optimization of the muffler is carried in order to bring the natural frequency of the aluminum lesser then the steel.

References

[1] Beranek, L., “Noise and Vibration Control”, McGraw- Hill, Cambridge, MA, 1988. [2] Brian J. Schwarz & Mark H. Richardson “EXPERIMENTAL MODAL ANALYSIS” Vibrant Technology, Inc. Jamestown, California 95327, October, 1999. [3] Wang jie et al. “The Modal Analysis of Automotive Exhaust muffler using PRO-E and ANSYS”. 2010, 3rd International Conference on Advanced Computer Theory and Engineering (ICACTE). 2010 IEEE. [4] M Rajasekhar Reddy & K Madhava Reddy. “DESIGN AND OPTIMIZATION OF EXHAUST MUFFLER IN AUTOMOBILES” International Journal of Automobile Engineering Research and Development (IJAuERD ) ISSN 2277-4785 Vol.2, Issue 2 Sep 2012 11-21. [5] Tirupathi R. Chandrupatla & Ashok D. Belegundu “Introduction to Finite Elements in Engineering” 3rd edition, 2001. [6] www.vibetech.com ME’SCOPE visual engineering service and Data Physics Corporation. [7] Design and Analysis of Automotive Mufflers for Noise Attenuation: A Review Rohit Suryawanshi 24 Nov 2020. [8] Design and Development for Exhaust Back Pressure Reduction with Noise Control for Motorcycles Mohamed Filsuf M. A 1 , Dr. S. Sankar 2 , Christy Mathew 3 , Sreejith K. V Vol. 7, Issue 5, May 2018. [9] Vibration Analysis and Design Modification of Automobile Silencer K.V. Panchal1, A.S. Pawar2, S.M. Dhavale3, S.R. Tekale4, Prof. G.P. Bhagat International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 06 Issue: 04 | Apr 2019. [10] DESIGN, ANALYSIS AND EXPERIMENTAL VALIDATION OF MUFFLER IN AN AUTOMOTIVE SYSTEM Madhu Kumar M Aravind K U Dr. Maruthi B H Dr. Channakeshavalu K International Journal For Technological Research In Engineering Volume 2, Issue 12, August-2015. [11] Flow Induced Vibration Integrated Design of Exhaust Manifold System for Dual Valve Engine Balamurugan M, Deenadaylan S, Prof.Amos Robert Jayachandran J International Journal of Innovative Research in Science, Engineering and Technology (An ISO 3297: 2007 Certified Organization) Vol. 5, Special Issue 4, March 2016.

Copyright

Copyright © 2023 Anjan Pal. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.