Browse Topic: Exhaust pipes

Items (110)

Novel Exhaust system architecture for Petroleum Oil Tanker Application vehicle

2024-26-034501/16/2024

A large amount of heat given off by ATS on BS-VI exhaust system vehicle. Heat shield is required to protect the surrounding components. As per PESO (Petroleum and Explosives safety organization) guidelines for POL Application vehicle is that,(i)the surrounding temperature should not be more than 180° C and (ii) there is no spillage of any petroleum product to the bare surface of exhaust part directly. In BS-VI vehicle the heat given off from ATS is higher than the BS-IV vehicle. Typically flexible or wrap around heat shield is provided over ATS. In BS-VI flexible heat shield is not possible as more sensors and components are coming. In this project the novel design of heat shield (combination of flexible and metallic sandwich) on exhaust system is used. This design ensures the surrounding temperature is below 180° C and there is no spillage of petroleum product to the bare surface of exhaust parts (Including Tail pipe, Exhaust main pipe and ATS) directly. Also this design protect the

Sahoo, Rajanikanta, Khandagale, Anup, Manoharan, Logeshwaran, Kumar, Pravin

Exhaust Noise Development Based on System Model

2022-01-073603/29/2022

Exhaust noise performance has been developed using vehicle. Recently, the demand on reducing vehicles and untact development is increasing. In this study, the method for developing exhasut noise using system models was researched. The exhaust noise can be estimated using engine sound source and exhaust system's transfer functions. We measured engine sound source strength and exhaust system's insertion loss in experimental approach. We drew the theoretical equation leading to tail pipe noise with 2 systems' inherent property and considering connection point conditions such as impedences. We compared the estimated noise with measured using several vehicles. We concluded this approach is helpful for qualitative evaluation for the developing vehicle's exhaust noise without making vehicles. After estimating exhaust noise, we can set the system's target to meet the vehicle's target. Using this approach, it is expected that the exhaust noise can be estimated in advance of manufacturing

Park, Sangyoung

Performance Optimization of an Exhaust System for 4 Cylinder Engine by Implementation of Computational Fluid Dynamics, Acoustic and Thermal Analysis

2022-01-076503/29/2022

The engine system requirements have changed from being focused only on delivering engine power to now having to meet environmental emission standards. The exhaust system collects exhaust gases from the combustion cylinders, eliminates dangerous pollutants, decreases noise, and discharges the purified exhaust gases at a safe distance from the vehicle's occupants. Designs of lightweight models for exhausts were always aimed at using newer lighter materials. As the design of an exhaust is more or less fixed, this approach is hardly profitable anymore. The most important components of an exhaust system are the exhaust manifold, the catalytic converter, the muffler, the resonator and connecting all of them together are connecting exhaust pipes. In this paper, the optimization of the various elements of 4 cylinder 1.8L engine exhaust system is carried out with the help of analysis software ANSYS 19.2 workbench, by performing ‘Steady State Thermal Analysis’, ‘Acoustic Analysis’ and simulating

Aiyan, Mohammed, Sagar, S Sumanth, Raghav S, Sanjay

Design and Optimization of an SUV Engine Compartment Undershield based on Latin Hypercube Design Method and Multi-island Genetic Algorithm

2022-01-020103/29/2022

Vehicle engine compartment thermal management performance ensures engine performance and reduces pollutant emissions, and a suitable temperature range in the engine compartment during vehicle operation is critical to reducing carbon emissions. The design of the engine compartment components affects the thermal fluid flow performance in the engine compartment, which in turn affects the engine compartment thermal management performance, so it is necessary to explore the optimization of engine compartment components. In this paper, based on the phenomenon that the engine compartment undershield of an SUV caused abnormally high temperature on the surface of the engine compartment parts due to design defects, the engine compartment was modeled and simulated by STAR-CCM+, and it was found that the undershield caused hot air flow back, which was not conducive to engine compartment heat dissipation, so the undershield needed to be redesigned. The shape of the undershield was redesigned and

Liu, Yong

Performance Optimisation of an Exhaust System for 4 Cylinder Engine by Implementation of Computational Fluid Dynamics, Acoustic and Thermal Analysis

2022-01-067703/29/2022

Aiyan, Mohammed, Raghav S, Sanjay, Sagar, S Sumanth

Tailpipe emission study of aged after treatment system on Medium duty commercial vehicle

2021-26-021509/22/2021

As the emission norms are getting stringent in BSVI and regulations like OBD-II on vehicle. It is essential to define the life of exhaust after treatment along with the vehicle. The After treatment mainly consist DOC+DPF+SCR. Lubricating oil consumption is always be there with engine running condition and these additive oils contains phosphorus or zinc which gives an adverse effect on DOC and there is unburnt hydrocarbon (UNHBC), SOF in tail pipe that get accumulated in DPF which further require regeneration means a higher temperatures in exhaust after treatment (EATS ) and as the regeneration count increases there is ash accumulation in DPF that reduces its capability for soot accumulation. The tail pipe emission also consist Sulphur which has a negative impact on SCR for Nox conversion. So in present study we analyze the effect of (1) Chemical aging (2) Thermal aging on 3.77 liter diesel engine after treatment. A test cycle was prepared to run durability for EATS which consist total

Tiwari, Amit, Durve, Anurag, Srinivasan, Pradhan, Barman, Jyotirmoy

DESIGN AND ANALYSIS OF A MUFFLER FOR ENGINE EXHAUST NOISE AND HEAT REDUCTION

2021-28-012809/15/2021

Exhaust noise and heat from engines is one of component noise pollution to the environment. Exhaust systems are developed to attenuate noise meeting required db levels and sound quality, emissions based on environment norms. Mufflers are important part of engine system and commonly used in exhaust system to minimize sound transmissions caused by exhaust gases and reduction of heat. Attaching a muffler in the exhaust pipe is the most effective means of reducing noise and heat. The aim of our project is to design and analyse a muffler for engine exhaust noise reduction. The suitable design and development will help to reduce the noise level and heat level, but at the same time the performance of the engine should not be hampered by the backpressure caused by the muffler. In this analysis 3D models are constructed using Solid Works software before exporting to ANSYS FLUENT CFD software for analysis. At ANSYS/FLUENT, pressure conditions will be specified as the inlet and outlet boundary

Deepan Kumar, Sadhasivam, Praveenkumar, Nagarajan, S, Arulkumar, N, Boopalan, PRAVEENKUMAR, S

Tesla's Cybertruck is audaciously austenitic

20AUTP06_0306/01/2020

A proprietary 301-series stainless steel gives Tesla's first pickup truck unique sales attributes while saving tooling cost. Not since Ford's epic switch to aluminum for its F-Series body structures has an automaker's materials strategy created such a buzz. Tesla's decision to use stainless steel for its upcoming Cybertruck, as part of what CEO Elon Musk calls an “exoskeletal” architecture, aims to give the new electric pickup strength and durability beyond that of its competitors. The vehicle is slated to enter production in late 2021. Musk described the corrosion-resistant, 3-mm-thick (.118-in) sheet specified for Cybertruck as “ultra-hard 30X cold-rolled stainless-steel,” indicating an alloy variant developed from 300-series stainless steel. This popular class was used by DeLorean (304 alloy) in its roughly 10,000 DMC-12 sports cars, and by heavy-truck maker Autocar (302 alloy) in a small-volume run in the 1960s. During the same period Ford also experimented with a few stainless

Brooke, Lindsay

Ammonia Measurement Investigation Using Quantum Cascade Laser and Two Different Fourier Transform Infrared Spectroscopy Methods

2020-01-036504/14/2020

Most diesel engine exhausts have been fitted with SCR (Selective Catalyst Reduction) in order to reduce NOX (Oxides of Nitrogen) by using NH3 (ammonia). However, both NOX and NH3 have been classified as compounds hazardous for the environment and human health. If the reaction between NOX and NH3 is unbalanced during treatment, it can lead to either NOX or NH3 being released into the environment. Accurate measurement is thus necessary. QCL (Quantum Cascade Laser) and FTIR (Fourier Transform InfraRed) are two methods that have been used to measure NH3 and NOX directly in diesel engine exhausts. However, only a few studies have compared those two methods of NH3 measurement, mainly from diesel engine exhausts. The aim of this paper is to compare the QCL and 2 different FTIR specifications for NH3 measurement directly from diesel engine exhausts under well-controlled laboratory conditions. Researchers have found that as NH3 is reactive, it is absorbed inside the exhaust pipe if the probe

Li, Nilton, El-Hamalawi, Ashraf, Barrett, Richard, Baxter, Jim

Nonlinear Acoustic Analysis of Loudspeakers in the Exhaust Dynamic Sound Technology

2018-01-155906/13/2018

An ongoing trend among automotive exhaust suppliers is the application of loudspeakers in their systems to tailor the exhaust sound to the customers’ needs. In addition to it, undesirable engine order noise can be cancelled by a closed loop control system. Due to the high sound pressure from the engine, the loudspeaker is often required to run at its power maximum. A higher input power eventually causes a nonlinear behavior, resulting in undesirable sound pressure level or harmonic distortion. Thus, the understanding of nonlinear behavior of loudspeakers and the recognition of dominant effects are required. This paper presents the main nonlinearities of loudspeakers and the comparison of theories on linear and non-linear loudspeaker models. For validation of the model, one loudspeaker enclosure and one typical exhaust system with a loudspeaker have been calculated. Ultimately it was found that a nonlinear loudspeaker model would be essential for a precise tuning of active exhaust sound

Kim, Hoi-Jeon, Schultz, Bernhard

High-Performance Rear- and Mid-Engine Vehicle Exhaust System Temperatures

2018-01-143604/03/2018

Hot surface ignition of combustible material is a known cause of vehicle fires. Although the detailed mechanisms of hot surface ignition are highly complex, the surface temperature is known to play a crucial role in this process. There has been limited previous work in the literature on this topic, much of which has focused on engine or exhaust system surface temperatures of the most common types of passenger vehicles. Also, much of this work was done in an unrepeatable manner and suffered from measurement technique induced errors. The focus of the present work is on repeatable and low measurement technique induced error temperature measurements of exhaust system surface temperatures of rear- and mid-engine sports cars. Temperature measurements were made at several points along the exhaust systems of vehicles both with and without turbo chargers on a 5-mile oval track. The exhaust system surface temperatures were examined under conditions of transient acceleration and steady-state

Papageorge, Michael, Colwell, Jeff

DMADV Approach for Engineering Optimization and Quality - Application and Adaptability in Indian Automobile Industry

2017-28-193007/10/2017

Indian Automobile Industry has started using Six Sigma for Vehicle Design and process improvement to compete with Global competition. This Paper describes how the Tools of Six Sigma shall be used as an Effective Tool for both redefining the Design and the Process Improvement. This Paper talks on the evolution of DMADV approach in Indian Automobile Industry compared to the related Trends in Other Manufacturing Sectors. The Author describes how the warranty failures in Commercial Segment Vehicle Category which was the selling talk for the Competition was addressed in Leading Indian Automobile OEM. As this Failure was adversely impacting customer satisfaction and no solution seemed forthcoming, top Management indicated to use a radically different approach to solve the problem within a years’ time. Among the different processes evaluated, DMADV six sigma approach brought in a creative approach to problem solving and improved systematic team work between the supplier, manufacturing

Jaswal, Anil Kumar, Chandrasekaran, Pradeep, Ramadoss, Surendran

The TEG Hot-End Heat Capacity’s Effect on the Power Output Stability for Harvesting Automobile Exhaust Energy

2017-01-016003/28/2017

While the car ownership increasing all over the world, the unutilized thermal energy in automobile exhaust system is gradually being realized and valued by researchers around the world for better driving energy efficiency. For the unexpected urban traffic, the frequent start and stop processes as well as the acceleration and deceleration lead to the temperature fluctuation of the exhaust gas, which means the unstable hot-end temperature of the thermoelectric module generator (TEG). By arranging the heat conduction oil circulation at the hot end, the hot-end temperature’s fluctuation of the TEG can be effectively reduced, at the expense of larger system size and additional energy supply for the circulation. This research improves the TEG hot-end temperature stability by installing solid heat capacity material(SHCM) to the area between the outer wall of the exhaust pipe and the TEG, which has the merits of simple structure, none energy consumption and light weight. Firstly, the exhaust

Xiao, Longjie, He, Tianming, Tan, Gangfeng, Huang, Bo, Ping, Xianyao

Powertrain Mounted Exhaust System Failure Correlation and Methodology Development in CAE

2017-26-026701/10/2017

Exhaust system is one of the complex automotive systems in terms of performance and strength prediction due to combination of transient mechanical and thermal loads acting on it simultaneously. Traditionally, most of automotive vehicles have exhaust systems with hot end mounted on engine and cold end mounted on chassis or BIW through hangers. A new powertrain mounted exhaust system was developed in-house. This exhaust system underwent validation and evaluation during development phase. Durability concerns were observed on exhaust system in Track test and gear shift durability test. This paper focuses on identifying the root cause of these concerns based on the failures observed during evaluation in Accelerated Durability (ADT) and gear shift durability (GSD) tests. Based on the architecture and packaging space challenges in vehicle, engine is mounted on two mounts and a roll restrictor. Muffler, which has higher inertia, is mounted at higher offset with respect to engine rolling axis

Mohapatra, Durga Prasad, Kangde, Suhas, Londhe, Abhijit, Srikanth, N N, Singh, Pravin

Field Failure Resolution of a Tractor Engine Exhaust System Using Constrained Single Objective Optimization and Stochastic Analysis

2017-26-023301/10/2017

The tractor engine related mounting brackets are very critical due to different aspects of vehicle performance, durability and noise. These mounting bracket have been designed as a framework to support engine external parts like muffler, exhaust tail pipe, alternator etc. Vibration and fatigue has been continuously a concern which may lead to structural failure and performance issues. Various such failures are faced regularly by automotive industry and finite element based analysis are used to resolve them. The resolution is done by playing with the component thicknesses, material, by providing additional support etc. However, due to large degree of uncertainty associated with the loading, boundary conditions, manufacturing, environmental effects; still there is some probability of failure. This paper focuses on a field failure issue of an exhaust system of a tractor and subsequent concern resolution. Multiple field failures like Under Hood Muffler (UHM) lug failure and UHM mounting

Perumal, Solairaj, Kumar, Abhay, Mahajan, Arun, Redkar, Dinesh, Balakrishnan, Sureshkumar

Optimization of Muffler Acoustics Performance using DFSS Approach

2016-01-129204/05/2016

Noise pollution is a major concern for global automotive industries which propels engineers to evolve new methods to meet passenger comfort and regulatory requirements. The main purpose of an exhaust system in an automotive vehicle is to allow the passage of non-hazardous gases to the atmosphere and reduce the noise generated due to the engine pulsations. The objective of this paper is to propose a Design for Six Sigma (DFSS) approach followed to optimize the muffler for better acoustic performance without compromising on back pressure. Conventionally, muffler design has been an iterative process. It involves repetitive testing to arrive at an optimum design. Muffler has to be designed for better acoustics performance and reduced back pressure which complicates the design process even more. A hybrid type muffler is the most commonly used muffler in automotive industry and it plays an important role in noise attenuation by using a combination of impedance mismatch and absorption

Dixit, Manish, Sundaram, V, Kumar S, Sathish

A Novel Approach for Flow Simulation and Back Pressure Prediction of Cold End Exhaust System

2016-28-023502/01/2016

The performance of any automotive engine depends not only upon its core engine parts but also on the effectiveness of the sub-systems attached to the engine, like the intake, fuel, engine cooling and exhaust systems. The exhaust system being a critical system of any automotive vehicle plays a responsible role of improving the ride quality of the vehicle and fuel economy. The effective design of exhaust system is critical in order to ensure the required exhaust gas is exited from the engine and at the same time the noise is attenuated. In this paper a novel approach is developed in order to characterize the flow through the cold end exhaust system and reduce the pressure drop to achieve desired performance. The exhaust system attenuates the noise from the engine without deteriorating the engine performance by ensuring an optimum value of exhaust back pressure. Exhaust back pressure is one of the crucial parameters that are always scrutinized by the automotive manufactures to ensure that

Dixit, Manish, Sundaram, V, Sathish Kumar, S.

Study of Pressure Losses of Unsteady Compressible Flows in Three- Way Junctions

2015-24-239909/06/2015

The aim of this paper is to extend the evaluation of the accuracy of published 1-D pressure loss coefficients which are used in 1-D gas dynamics models, in unsteady compressible flows propagating in the exhaust pulses in manifolds. These pressure loss coefficients were derived from the conservation of linear momentum over finite control volumes based on assumptions including steady flow. The objectives of this work were to evaluate the accuracy of the pressure loss coefficients over the type of flows generated by engine-like pressure pulses propagating in a range of three-pipe junctions. The evaluation was performed by reference to results from unsteady, compressible, 3-D Reynolds-averaged computational fluid dynamic (CFD - open source software OpenFOAM) simulations. Two of the junction branches represented the exhaust pipes from two cylinders and the remaining was the outlet pipe. All pipes had a diameter of 25mm with length ratio 1:2 between inlet and outlet. Y junctions of 30° and

Nikita, Christina, Hardalupas, Yannis, Taylor, Alexander

Influence of Linear and Parabolic Elements in Structural Rigidity of Converter Mounting Brackets

2015-01-132604/14/2015

Generation of discretization with prescribed element sizes are adapted to the geometry. From the rules of thumb, for a complicated geometry it is important to select the reasonable element order, shapes and size for accurate results. In order to that, this paper describes the influence of elemental algorithm of the catalytic converter mounting brackets. Brackets are main source of mounting of various systems mainly intake and exhaust in the engine. In hot end exhaust system, a bracket design plays a vital role because it has to withstand heavy structural vibrations without isolation combined with thermal loads. Bracket design and stiffness determines the whole catalytic converter system's rigidity. So, here discretization of converter brackets by linear and parabolic elements is studied with different elements types and compared. The study shows disparity in the structural accuracies of the brackets in each of elemental orders respect to the element shapes i.e. in the stiffness and

Rajadurai, Sivanandi, Mani, Guru Prasad, Raja, Kavin, Mohan, Sundaravadivelu

Design of Durable Vanadium - SCR Catalyst Systems for Heavy - Duty Diesel Applications

2013-26-004901/09/2013

The emission regulations for mobile applications become stricter in Euro-IV to Euro-VI levels. Carbon monoxide and hydrocarbon can be removed by efficient Diesel Oxidation Catalysts (DOC) but Particulate Matter (PM) and NOx are more demanding requiring the use of active methods (urea-SCR and DPF) which will be world-wide implemented in the 2010's. Durable, coated V-SCR catalysts are based on stabilized raw materials and tailored preparation methods. Coated V2O5/TiO2-WO3 catalysts (ceramic 300/400 cpsi and metallic 500/600 cpsi) were evaluated by laboratory and engine bench experiments. Traditional V-SCR catalysts are durable up to about 600°C and have a high efficiency at 300°C-500°C. SCR activities were tailored to be higher also at 200°C-300°C or 500°C-600°C. The use of thermal stabilizers or the vanadium loading variation enabled the changes in operation window and stability. The stabilized V-SCR catalyst kept the SCR activity also after ageing at 600°C-650°C when the reference lost

Maunula, Teuvo, Viitanen, Arto, Kinnunen, Toni, Kanniainen, Kauko

SAE Powertrain & Energy 2012-09-26

12DPE092609/26/2012

Demon alcohol? The impact of Ethanol fuels on regulated tailpipe emissions is studied and assessed by two Chrysler researchers in a 2012 SAE technical paper.

Development of Unified Exhaust System Supported by CAE Software Programs

2010-36-047310/06/2010

In spite of the changes in vehicle performance, one of the current challenges is to get components applicable to different vehicles with no changes in the project. Simulations made with specific numerical programs enable this process of unifying components, for different platforms, to be applied to the exhaust system. The projects proposed, based on the results obtained with the simulation programs, were tested experimentally. It was proven that the results of the simulation proposals correlated to the experimental results. This ultimately provided simplification to the project, with gains in logistics and productivity. Besides the technological process involved, possibilities to reduce costs can also be considered.

de Oliveira, Anderson Ricardo, da Silva Moura, Marcio, da Silva de Amorim, Osmar, de Oliveira Silva, Ricardo

Steady-State and Transient Motor Vehicle Exhaust System Temperatures

2009-01-001304/20/2009

One of the known causes of motor vehicle fires is hot surface ignition of combustible material that contacts engine exhaust system components. While ignition is a complicated phenomenon, the temperature of the surface is known to be an important parameter. However, little data is available in the literature concerning exhaust system temperatures, and much of this data is confounded by thermocouple attachment techniques and undocumented variations in driving conditions. In the present study, engine exhaust system temperature measurements were conducted using six test vehicles on a level, 2-mile oval test track at constant vehicle speeds ranging from 0 (idle) to 70 mph. By normalizing transient temperature curves with these steady-state temperatures along with ambient temperature, the rates at which the exhaust system components warm up and cool down are also compared. The effect of thermocouple mounting technique was evaluated by conducting identical testing with the thermocouples

Colwell, Jeff D., Biswas, Kaushik

Waza (Skilled Craftsmanship) that Created RA272 Exhaust Pipe used in Formula 1 Race in 1960's

2008-01-054704/14/2008

This study attempted to faithfully reproduce and scientifically analyze the process of formation of the exhaust pipe of the winning RA272 engine used in Formula One in the 1960's, using the waza (skills) employed in its fashioning, which have been handed down by its makers. This analysis showed that the manual bending method, used to create the RA272 exhaust pipe, which was filled with sand and bent while being flame-heated, without the use of figures or molds, was superior to the mechanical bending method of that time, from the standpoint of short-term period of production. We have determined that the pipe displays that the microstructure of the material remains stable, even at exhaust temperatures of 700°C to 900°C, and that useful information on the pipe's shape stability and mechanical strength has been provided.

Ueda, Koji, Takahashi, Ryuichi, Konno, Osamu

Application of Exhaust Pipe Restriction Technique to a Small Two-Stroke Engine

2007-32-003210/30/2007

A simple method to reduce HC emissions caused by fuel short-circuiting in a two-stroke engine is to apply a certain restriction to the exhaust gas flow in the exhaust pipe. This technique, developed for motorcycles, vehicles and outboards, has been applied to a small off-road two-stroke engine with a constant speed operating condition. In order to assess the feasibility and effectiveness of this technique for the reduction of HC and CO emissions in such an engine, a butterfly valve was installed in the exhaust pipe next to the exhaust port. Based on test results using the butterfly valve, a cylindrical restrictor was developed to generate various restrictions to the gas flow in the exhaust pipe and consequently reduce the fuel short-circuiting. The effectiveness of the restrictor on emission reduction was further improved by leaner air/fuel mixture. The experimental results showed improved engine performance including the best 24% reduction of total weighted HC and 25% reduction of

Watson, Finlay Llewyn, Hong, Guang

Analysis for suitability of Loop and Cross Scavenged System for Stratified Charged Engine

2007-24-006409/16/2007

The results obtained with Loop & Cross scavenged systems reveal that during early charging period the scavenged through losses are more in loop scavenged system in comparison to cross scavenged and in later part both shows considerable improvement still the probability of trapping of charge in cross scavenged are higher. Therefore stratification of charge helps in reducing the loss of fuel in both the system. But in case of cross scavenged system due to better trapping characteristics throughout the scavenging process leads to improved combustion too. Cross scavenged system employed with dual intake system shows reduction in fuel of the order of 26% & 29.7% for 40% & 50% flow through AASL, whereas, loop scavenged system shows 12.85% & 14.4% for the same flow through AASL.

Berwal, A. K., Gupta, V. K., Saxena, Mukesh

Estimating Actual Exhaust Gas Temperature from Raw Thermocouple Measurements Acquired During Transient and Steady State Engine Dynamometer Tests

2007-01-033504/16/2007

Thermocouples are commonly used to measure exhaust gas temperature during automotive engineering experiments. In most cases, the raw measurements are used directly as an absolute indication of the actual exhaust gas temperature. However, in reality, the signal from a TC is only an indication of its own tip temperature. The TC indicated tip temperature can deviate significantly from the actual gas temperature due to factors such as thermal capacitance of the tip itself, and heat transfer to the exhaust pipe wall through conduction and radiation. A model has been developed that calculates the effects of these factors to provide an estimate of the actual exhaust gas temperature. Experiments were performed to validate the model under both transient and steady state engine dynamometer conditions utilizing three popular sizes of TCs. Good correlation among predictions for various TC sizes confirms the model's accuracy. This tool enhances the quality of exhaust gas temperature measurements

Son, Seha, Kolasa, Arthur E.

The Effect of Tailpipe Orientation on Carbon Monoxide Dispersion Patterns and Cyclist Exposure Levels

2006-01-062404/03/2006

This paper investigates the effect of tailpipe orientation on carbon monoxide (CO) dispersion patterns which is directly linked to the CO exposure levels that a cyclist can experience in Oxford City. The most common tailpipe orientations used in Oxford city vehicles have been identified. Following this, the dispersion patterns from various tailpipe orientations were experimentally investigated and the results used to construct contour maps of CO dispersion patterns. The contour maps were used to estimate the likely exposure levels a cyclist can experience. The real-world cyclist CO exposure levels were also measured in two routes in Oxford city and compared with those obtained from the contour maps and data from fixed site monitoring station. The results show that CO levels in the cycle lane are significantly affected by the tailpipe orientation and are higher than the recommended World Health Organization (WHO) exposure levels.

AL Zudi, F., Samuel, S., Morrey, D., Sehati, S., Woolcock, C.

Optimum Design of Exhaust System Using the Robust Design

2006-01-008204/03/2006

The exhaust system consists of more than one center resonator and main resonator. Its function is to reduce the tail pipe noise of the exhaust system. The aim of this work is cost and weight reduction by eliminating center resonator that is basically included in design of the exhaust system using the Robust Design. This paper shows the procedure of optimum design of the exhaust system for Cost/Weight/NVH aspects with the Robust Design.

An, Hochan, Chae, Sungsoo, Kim, Hooinyun

Ion Current During the Exhaust Process Under the Idling Condition in a Spark Ignition Engine

2005-01-387210/24/2005

Recently, in order to warm up the catalyst temperature rapidly, the retard ignition management has been developed. However, the excess retard of ignition causes the combustion instability and misfire. In this case, the ion sensor has been used for detecting the combustion quality for the late burned cycle under the idling condition. Several researchers have focused on the potential of ion-current measurement for the retard ignition management. However, the interpretation of ion-current during the exhaust process under the idling condition is not clear. In this study the source of ion-current for the late burned cycle during the exhaust process is focused. In order to measure the flame propagation process in the cylinder and the exhaust pipe, the single-cylinder test engine was used instead of production engine. Several ion probes were mounted on the cylinder head gasket, the piston head and the exhaust pipe for detecting the flame front. There are significant signals in the spark ion

Yoshiyama, Sadami, Tomita, Eiji, Kitawaki, Shunsuke, Kamada, Keizo

Simulation of Radiation Effects in the Presence of the Exhaust System

2005-01-206005/10/2005

The increasing packing and power density in vehicles makes the thermal environment in the engine compartment more and more severe. A critical area in terms of radiation are the components facing the exhaust system. This paper shows the simulation methods applied at MAGNA STEYR finding hot spots and endangered parts when looking on the effects of radiation. The simulation runs in parallel to design, gives a reliable rating of variants and helps the designer to optimize his system. The influence of an exhaust manifold design change from double-walled to a single-walled on the steering system in a right hand drive vehicle is shown. This change was done due to cost reduction, but also resulted in additional costs for heat protection. The methods are applied in advance of the physical prototypes and help to find good measurement positions for the physical testing also.

Moshammer, Thomas

An Optimal Design Methodology for a Family of Perforated Mufflers

2005-26-05301/19/2005

Usually when mufflers are designed by well established numerical techniques like boundary element method or finite element method, the numerical model generation is time consuming often limiting the user to try various other possible design alternates. This paper proposes a shorter and faster way to handle such problems by using the conventional four-pole method which retains the transfer matrix for a muffler, this matrix keeps updating with combination of various possible muffler elements. This proves to be a quite efficient one-dimensional approach giving results with satisfactory accuracy. The muffler designs that can be made include all types of expansion chambers, Helmholtz's resonator, extended inlets/outlets, the whole family of perforated elements and many more. It provides a measure of evaluation of the muffler in terms of their Transmission Loss (TL), Insertion Loss (IL) and Noise Reduction (NR). This paper also provides a comparison of experimental results of silencer of a

Mohanty, A. R., Pattnaik, S. P.

CFD Modelling of 3-Way Catalytic Converters with Detailed Catalytic Surface Reaction Mechanism

2004-01-014803/08/2004

This paper presents a 3-D CFD modelling of flow and heterogeneous reactions in catalytic converters. The pressure and velocity fields in the catalytic converters are calculated by the state of the art modelling technique for the flow resistance of catalyst substrate. A surface reaction model is applied to predict the performance of a three-way Pt/Rh catalyst. A reaction mechanism with detailed catalytic surface reactions for the 3-way catalyst is applied. The novelty of this approach is the use of a surface chemistry solver coupled with a 3-D CFD code in the entire computational domain of the catalyst substrate that allows flow distribution for complex configurations to be accounted for. The concentrations of the gas species and the site species are obtained. A comparison between the simulation results and the experimental data of a three-way catalyst was made.

Chen, Ming, Aleixo, Joe, Williams, Shazam, Leprince, Thierry, Yong, Yi

Development of Catalytic Converter for 2 - Stroke Engine Powered Vehicles

2004-01-109003/08/2004

Scooters and motorcycles are favoured as economical forms of transportation throughout much of Asia. This is particularly true of vehicles with 2 stroke power plants, thanks to the high specific output produced by the simple, less costly engine. However a serious disadvantage of these vehicles is that they emit considerably higher volumes of gaseous pollutants per driven kilometer than do other automobiles. This paper presents new development of a catalytic converter for 2 stroke powered vehicles which uses metallic catalyst support coated with platinum. With an improved inlet header design the conversion efficiency has improved significantly and maximum power loss was than 5 % over the entire speed range.

Tamilporai, P., Chandrasekaran, S., Subramaniyam, S., Jancirani, J.

CFD Analysis and Experimental Validation of the Inlet Flow Distribution in Close Coupled Catalytic Converters

2003-01-307210/27/2003

The unsteady flow effects in two different close coupled catalytic converters were investigated in order to achieve a better understanding of the steady state experimental tests which are usually performed to evaluate a flow distribution. Firstly the validity of a CFD model was achieved through a comparison of some steady state simulations with the results of HWA experimental measurements. Several different formulations of the uniformity index, that were found in literature, were then compared, trying to highlight the strengths and shortcomings of each one. Further information was derived from a comparison of the two catalysts that were tested to achieve a general methodology that would be useful for future analysis. Finally, a new approach to evaluate the flow distribution using a steady state analysis was proposed by comparing the results of a transient simulation that was obtained for a whole engine cycle.

Badami, M., Millo, F., Zuarini, A., Gambarotto, M.

Modeling of Scavenging and Plugging in a Twin-Cylinder Two Stroke Engine Using CFD

2003-32-002009/16/2003

This paper presents a study on multi-dimensional CFD modeling of scavenging and plugging in a twin-cylinder two-stroke engine. A general-purpose CFD code, KIVA, was extended to track an arbitrary number of moving pistons. The code was also modified to allow piston snapping through complicated transfer ports. Thus, a multi-cylinder simulation together with a full exhaust manifold to fully account for the interaction between scavenging and plugging becomes possible. The developed code is intended to be a numerical tool for exhaust-manifold design and optimization. The studied engine is a five-port loop scavenged twin-cylinder engine with a cylinder displacement of 432 cc. The computed exhaust pressure was compared with measured data, and reasonably good agreement was obtained. The results were also compared with those from a one-dimensional gas dynamics model, which over-predicts the plugging intensity while under-predicting the pressure loss in the exhaust manifold. It is also suggested

Zeng, Yangbing, Strauss, Sebastian

3D Macroscopic Model for Fluid Flow and Soot Deposit in Wall Flow Honeycomb DPF

2003-01-083403/03/2003

This paper presents an original three dimensional model for fluid flow and soot deposition in the overall wall flow honeycomb DPF. First, hot-wire experimental velocity measurements carried out along the DPF outlet cross-section are shown to highlight the flow heterogeneity. Then coupled 1D local momentum and mass balance equations to describe a bundle of channels are proposed and discussed. The model is applied to simulate the loading of a bundle of channels. Two typical cases are considered to illustrate heterogeneity problems: (i) a transverse wall permeability gradient and (ii) the initial blockage of two entrance channels. In this latter case, the heterogeneity effect is found to be confined in the neighbor channels. Finally, a macroscopic form of this set of 1D local equations, obtained using a method of volume averaging applied on a cross-section filter element which consists of several unit elements, is described. First simulations of loading of a square cross-section DPF

Oxarango, L., Schmitz, P., Quintard, M., Bardon, S.

47 Development of a Titanium Material by Utilizing Off-Grade Titanium Sponge

2002-32-181610/29/2002

Titanium alloy for forging and pure titanium material for exhaust systems have been developed. The forging alloy will be applied to production of lightweight motorcycle frames and the pure titanium will be applied to improve engine performance. The materials have been made inexpensive by the use of off-grade sponge that includes many impurities for production of titanium ingot. Stable characteristics have been obtained by controlling oxygen equivalent after setting the volume of tolerable impurities by considering mechanical properties and production engineering. In spite of low-cost, the material provides the same design strength compared to conventional material, and enables parts production with existing equipment. A review of manufacturing and surface treatment processes indicated a reduction in the price of titanium parts produced with this new material. It is expected that this technology is suitable for automobile applications and may be applied to a wide range of other titanium

MARUI, Yuji, KINOSHITA, Toyotaka, TAKAHASHI, Kyo

Flextube™ Catalyst Performance In 4-Stroke Motorcycle Exhaust Systems

2001-01-182312/01/2001

An analysis of 4-stroke motorcycle emission systems indicates that a heat tube has the potential for meeting the regulatory standards if the location in the exhaust pipe matches the specific operating temperature requirements of the device. The location of a heat tube is determined by the diameter and shape of the exhaust pipe. Since the exhaust flowrate and temperature across the catalytic device determine its effectiveness, it is suggested that a flexible catalyzed tube, which could be placed anywhere in the exhaust, would have a greater potential than a rigid heat tube for solving a wide range of emission application needs. To maximize the benefit from such a simple, cost-effective device, application of the “flex-tube catalyst” was studied over a wide range of conditions. A test matrix that used high and low levels of Pt/Rh ratio and tube diameter was used to study “flex-tube catalyst” performance in 4-stroke motorcycle exhaust systems. Engine variables include inlet temperature

Larkin, M.P., Dettling, J.C., Galligan, M.P.

INFLUENCE OF LOCATION OF CATALYTIC CONVERTER ON TWO-STROKE ENGINE PERFORMANCE

2001-01-182012/01/2001

In modern two-stroke SI engine applying one or two segments of catalytic converter in exhaust system is needed to fulfil requirements of emission of toxic components in burnt gases. In the paper dependence of location of catalytic converter with defined mass flow rate and resistance inside outflow system on engine performance, especially power and fuel consumption is described. Paper gives mathematical model of gas flow in a ‘tuned’ exhaust system with taking into account resistant of gas flow through catalytic converter. On the base of mathematical model calculation of physical parameter of gas for different location of monolith were done with overall engine output parameters. This enables optimisation of whole exhaust system at conservation of high temperature in the monolith. In the paper result of simulation (torque, fuel consumption, residual gas etc.) were given in comparison to original engine. Also experimental results made on stand with 125 cc two-stroke engine with the same

Mitianiec, Wladyslaw

A Camera Based Solution for Dynamic Measurements

2001-01-347010/01/2001

This paper presents a new contact less 6D motion measuring system for automotive test bench instrumentation. The measurement device is based on three linear CCD cameras, which are mounted on a fixed rigid structure. These three linear CCD cameras can track the 3DOF position of IR emitting LED's in the environment. Combining three LED's on one rigid body allows calculating the 6DOF position (positions and orientations) of a rigid body. Position and orientation of multiple objects in space are measured on-line. The measurement principle is explained together with three case studies: A suspension testing system An exhaust pipe deformation test system Quasi static car body deformations Using these three case studies, the requirements for such a system are explained both from a hardware and a software point of view.

Wens, Luc

Tapped and Flanged Exhaust Connections for Small Engines

J624_200107 (Current)07/31/2001

This SAE Recommended Practice applies to domestic four-cycle air- and water-cooled engines having a maximum of 14.9 kW (20 hp) or less in power output and/or 0.82 L (50 in3) or less in displacement, with horizontal or vertical crankshafts. The engine shall be furnished with a minimum of either a tapped exhaust port or two tapped holes and flat port face making possible use of a threaded connector or one of the flanges shown in Figure 1. Exhaust flanges are sized to be used with mild steel or aluminized steel butt-welded tubing.

Small Engine and Powered Equipment Committee

Development and Experimental Study of a New Diesel Exhaust Particulate Trap System *

2000-01-284610/16/2000

Diesel exhaust particulate trap system is one of the most effective means to control diesel particulate emissions from diesel vehicles. In this paper, a recently developed diesel exhaust particulate trap system was described and experimentally studied. This system employed a wall-flow ceramic foam filter, which was made of silicon carbide or chromium oxide. And this system was equipped with a microwave heater for the purpose of filter regeneration. Engine dynamometer testing, vehicle bench testing and on-road evaluation of this system were conducted. The experiments studied on the filtration efficiency of this system, the effectiveness of filter regeneration, the power penalty of the vehicle, the ability of noise suppression of this system, and the durability of this particulate trap system. The experimental results showed that this diesel particulate trap system was effective, reliable, and durable. It is feasible to use this system to control particulate emissions from buses in large

Zhi, Ning, Xinyun, Zi, He, Yongsheng

Numerical modeling of unsteady reacting flows in the exhaust system of an S.I. engine including the catalytic converter

2000-05-017506/12/2000

Recent advances in the field of numerical modeling of unsteady reacting flows in the exhaust system of s.i. engines are presented in the paper. In particular, it is shown that the integration of a suitable chemical and thermal model for the catalytic converter within a 1D fluid dynamic simulation code has allowed the prediction of the exhaust gas composition from the cylinder to the tailpipe outlet, considering its variation across the catalyst. The composition of the exhaust gas, discharged by the cylinder, is calculated by means of a two- zone combustion model, including emission sub-models. The catalytic converter is simulated by a 1D fluid dynamic and chemical approach, considering laminar flow in each tiny channel of the substrate and chemical reactions in the solid phase, within the wash-coat. The predicted reaction rates are used to determine the specie source terms to be included in the one-dimensional fluid dynamic conservation equations. The heat released by the exothermic

D'Errico, Gianluca, Ferrari, Giancarlo, Onorati, Angelo

Experimental Study on the Influence of Motorcycle's Noise Reduction Through Structure and Dimension Variation of the Muffler

2000-05-030306/12/2000

With the rapidly development of motor technology, the environment pollution caused by motor exhaust gas and noise gets more and more attention. The paper presents the experimental study on influent factors of Motorcycle muffler noise reduction, including changes of length and radials of the muffler pipe, the ratio m of expand cavity, the size or shape of tail pipe, the position of isolation plate inside a cavity, and verify of the total volume of the muffler. Rules of muffler structure design are studied.

He, Yansong, Luo, Laijun

Development of Dual Wall Air Gap Exhaust System

2000-01-020503/06/2000

The strict new emission regulations have resulted in the development of new techniques to meet the control of cold-start emission in various competitive ways. In this study, the dual walled air gap exhaust pipe system is developed as an effective countermeasure to reduce pollutant exhaust gas emission, particularly to reduce pollutant exhaust gas emission at cold start and idling stage, in which the catalytic converter has not reached to light-off temperature. In this study, it is shown that dual walled air gap exhaust system can shorten the time to reach to light off temperature of the catalytic converter in cold start state, and reduce the emission of Hydrocarbon (HC) significantly due to its low thermal capacity and high thermal insulation effect. In the study, a thermal analysis of the dual walled air gap exhaust pipe system has been done using the computational fluid dynamics method. The analytical results were compared with the experiments obtained from specially designed bench

Kyu -Hyun,, Lee, Chang -Yeul,, Shim, Wan-Bum,, Kim

The Innovative Reinforcement Technology of Thin Wall Ceramic Substrate Having High Coatability

2000-01-049603/06/2000

By focusing on light weight and high coatability, a substrate has been successfully developed that has strong and stiff walls but does not sacrifice porosity. For increasing the isostatic strength, outermost cells of substrate are thickened more than inner cells. Furthermore, for preventing the front section of substrate from abrasion by strong deflected exhaust gas flow or contamination, only several millimeters of the front section are stiffened. This reinforced substrate is stronger and stiffer than the low porosity's one, and its coatability is as same as the current substrate.

Tanaka, Masakazu, Nishimura, Mamoru, Murata, Masakazu, Itou, Keiji

Development of A Low Emission, High Performance Motorcycle

1999-01-325809/28/1999

It has been already scheduled to apply exhaust emission regulations onto motorcycles, intending to make exhaust gas cleaner. Several South-East Asian nations issued new regulations in 1996, then Japan in 1998, and European nations are planning to start stricter regulations from early 2000.The required emissions level of these new regulations are so strict that it is estimated that no engine will be able to pass the regulation without installing complicated devices, and a catalytic converter as well. The development of new technology in this category has become an urgent subject. This paper describes our development of an exhaust system including a honeycomb-type catalytic converter for large displacement 4 stroke motorcycle engines to meet even the proposed future regulations in Europe (EC Stage II) without sacrificing its performance. This paper also reports on observed troubles and our solutions during the development.

Tamura, Junji, Takagi, Shigeo

Analysis of Pulsation Inside Pipe and Study on Exhaust Sound Characteristics of V Type 8 Cylinder Engine - Study on Optimized Front Pipe Junction Structure

1999-01-165105/17/1999

The research of pulsation wave propagation inside exhaust pipe installed in V8 engine shows that pulsation from engine was changed by joining two front pipes in entire exhaust pipe. In short, frequency of pulsation inside the pipe is not always equal to engine explosion first order frequency or its harmonics. Accordingly, structure of junction has been studied, which indicated that having volume at junction add engine revolution first order component pressure fluctuation to blow-down wave component and makes exhaust sound worse. This phenomena is caused by irregular explosion interval on each bank of V8 engine and phase delay of propagation at junction.

Hosomi, Mikiya

Exhaust Muffler Design and Analysis Using a Boundary Element Method Based Computer Program

1999-01-166105/17/1999

Typical automotive muffler designs contain complex internal components such as extended inlet/outlet tubes, thin baffles with eccentric holes, internal connecting tubes, perforated tubes, perforated baffles, flow plugs and sound-absorbing materials. An accurate performance prediction for highly complicated muffler designs would greatly reduce the effort in fabricating and testing of multiple design iterations for engineers. This paper discusses the use of a component-based computer simulation tool for design and analysis of exhaust mufflers. A comprehensive computer program based on the Direct Mixed-Body Boundary Element Method was developed to predict the transmission loss characteristics of muffler systems. The transmission loss is calculated by an improved four-pole method that does not require solving the boundary element matrix twice at each frequency, and hence, it is a significantly faster approach when compared to the conventional four-pole method. The numerical prediction of

Wu, T. W., Cheng, C. Y. R.

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