Browse Topic: Exhaust pipes
Exhaust gas recirculation technology is one of the main methods to reduce engine emissions. The pressure of the intake pipe of turbocharged direct-injection diesel engine is high, and it is difficult to realize EGR technology. The application of Venturi tube can easily solve this problem. In this paper, the working principle of guide-injection Venturi tube is introduced, the EGR system and structure of a turbocharged diesel engine using the guide-injection Venturi tube are studied. According to the working principle of EGR system of turbocharged diesel engine, the model of guide-injection Venturi tube is established, the calculation grid is divided, and it is carried out by using Computational Fluid Dynamics method that the three-dimensional numerical simulation of the internal flow of Venturi tube under different EGR rates injection. The flow field state, velocity field, pressure field and exhaust gas concentration parameters of the mixture formed by air and EGR exhaust gas in Venturi
Customer preference towards quieter vehicles is ever-increasing. Exhaust tailpipe noise is one of the major contributors to in-cab noise and pass-by-noise of the vehicle. This research proposes a silencer with an integrated acoustic valve to reduce exhaust tailpipe noise. Incident exhaust wave coming from the engine strikes the acoustic valve and generates reflected waves. Incident waves and reflected waves cancel out each other which results in energy loss of the exhaust gas. This loss of energy results in reduced noise at the exhaust tailpipe end. To evaluate the effectiveness of the proposed silencer on the vehicle, NVH (Noise, vibration, and harshness) performance of the proposed silencer was compared with the existing silencer which is without an acoustic valve. A CNG (Compressed natural gas) Bus powered by a six-in-line cylinder engine was chosen for the NVH testing. After NVH evaluation, it was found that when using the proposed silencer, overall exhaust tailpipe orifice noise
The automobile industry is going through one of the most challenging times, with increased competition in the market which is enforcing competitive prices of the products along with meeting the stringent emission norms. One such requirement for BS6 phase 2 emission norms is monitoring for partial failure of the component if the tailpipe emissions are higher than the OBD limits. Recently PM (soot) sensor is employed for partial failure monitoring of DPF in diesel passenger cars.. PM sensor detects soot leakage in case of DPF substrate failure. There is a cost factor along with extensive calibration efforts which are needed to ensure sensor works flawlessly. This paper deals with the development of an algorithm with which robust detection of DPF substrate failure is achieved without addition of any sensor in the aftertreatment system. In order to achieve this, a thermodynamic model of DPF substate was created using empirical relations between parameters like exhaust flow rate, exhaust
Decarbonization of commercial vehicles and off-highway machines is rapidly becoming a hot-button topic among regulators in the EU, Asia and North America. In addition to cracking down on emissions of light vehicles, various government agencies are now looking to reduce the tailpipe emissions from all manner of industrial equipment. Truck & Off-Highway Engineering attended an expert panel at the 2023 SAE COMVEC conference that covered renewable and low-carbon fuels as well as usage of hydrogen. The panel consisted of SMEs and engineers from various OEMs such as the Traton Group company MAN, Aramco and Ballard. They discussed the various ways in which these industries can reduce or even eliminate emissions from their machines while also discussing the economic feasibility of doing so
Ultrafine particles, in particular solid sub-100 nm particles pose high risks to human health due to their high lung deposition efficiency, translocation to all organs including the brain and their harmful chemical composition; due to dense traffic, the population in urban environments is exposed to high concentrations of those toxic air contaminants, despite these facts, they are still widely neglected. Therefore, the EU-Commission set up a program for clean and competitive solutions for different problem areas which are regarded to be hotspots of such particles. HORIZON AeroSolfd is an EU project, co-funded by Switzerland that will deliver affordable, adaptable, and sustainable retrofit solutions to reduce exhaust tailpipe emissions from petrol engines, brake emissions and pollution in semi-closed environments. VERT, a Swiss based international industry organization, has a long research history in the field of nanoparticle filtration and it is in charge of reducing tailpipe emissions
Automotives play a very important role in day-to-day human lives. The exhaust gas emitted from automotive vehicles of current technologies is one of the major contributions to global temperature increment. It is important to develop a system that can conserve energy and incorporate it into current vehicles which are in use. Phase change materials (PCM) are well known for energy storage applications because of their crucial thermophysical property known as latent heat of fusion. The gas from the exhaust pipe of automobiles can be considered a turbulent jet. With this assumption in this study, a system is proposed by combining jet impingement and phase change material at the exhaust pipe of automobiles to recover the thermal energy which is being let out into the atmosphere as waste. Liquid Gallium is chosen as a phase change material for this study because of its high thermal conductivity nature compared to other hydrocarbon-based phase change materials. Initially, a combined numerical
In this work, tailpipe carbon monoxide emission from a gasoline powertrain case study vehicle was analyzed for off-cycle (i.e., on road) driving to develop a virtual sensor. The vehicle was equipped with a portable emissions measurement system (PEMS) that measured carbon monoxide concentration and exhaust volumetric flowrate to calculate the mass of carbon monoxide emitted from the tailpipe. The vehicle was also equipped with a tailpipe electrochemical NOx sensor, and a correlation between its linear oxygen signal and the PEMS-measured carbon monoxide concentration was observed. The NOx sensor linear oxygen signal depends on the concentration of several reducing species, and a machine learning model was trained using this data and other features to target the PEMS-measured carbon monoxide mass emission. The model demonstrated a mean absolute percentage error (MAPE) of 19% when using 15 training drive cycles. Finally, a virtual carbon monoxide sensor was developed by removing the
To meet stringent emission norms and commercial vehicle customer demands, the selection of an after-treatment system (ATS) plays a considerable role. Therefore, the selected ATS should substantially reduce nitrogen oxide emission by proper decomposition of ammonia and particulate matter without significantly increasing the thermal stress on DPF. Though the BS-VI after-treatment architecture is derived from EURO-VI, only a certain level of technology for the vehicle operating conditions in India can be implemented. However, numerous vehicle operating condition challenges in the Indian market must be explicated. Correspondingly, it should be addressed with a robust durability validation methodology to enhance the ATS product performance in challenging environments. This paper discusses SCR catalysts emission performance and ammonia decomposition durability validation methodology for commercial vehicles. In addition, during various vehicle duty cycle conditions, the effectiveness of DPF
In the recent years and near future, the automotive environmental regulations have been and will be more stringent than ever before. The reduction of cold start tailpipe emission is the key for exhaust aftertreatment and emission control. As one of the effective catalyst heating approaches, EHC can be applied to reduce catalyst L/O time at engine cold start and then improve tailpipe emission with meeting stringent emission regulations such as China6b，Euro6d，US Tier3Bin30 and future China7，Euro7. In this paper, we will review our recent engineering work on EHC development associated with hybrid electrical vehicle for better emission control and exhaust aftertreatment
This SAE Standard establishes a method of disclosing the sweep-ability performance of self-propelled sweepers that use broom means for sweeping and collection, together with either a mechanical- or pneumatic-conveyance system for the transfer of “sweepings” into a collection hopper
A narrow focus on electrification and elimination of tailpipe emissions is unlikely to achieve decarbonization objectives. Renewable power generation is unlikely to keep up with increased demand for electricity. A focus on tailpipe emissions ignores the significant particulate pollution that “zero emission” vehicles still cause. It is therefore vital that energy efficiency is improved. Active travel is the key to green economic growth, clean cities, and unlocking the energy saving potential of public transport. The Challenges of Vehicle Decarbonization reviews the urgent need to prioritize active travel infrastructure, create compelling mass-market cycling options, and switch to hybrid powertrains and catenary electrification for long-haul heavy trucks. The report also warns of the potential increase in miles travelled with the advent of personal automated vehicles as well as the pitfalls of fossil-fuel derived hydrogen power. Click here to access the full SAE EDGETM Research Report
A novel laser-absorption gas sensing apparaOn-vehicle Testing at VERtus capable of measuring NO directly within vehicle exhaust was developed and tested. The sensor design was enabled by key advances in the construction of optical probes that are sufficiently compact for deployment in real-world exhaust systems and can survive the harsh, high-temperature, and strongly vibrating environment typical of exhaust streams. Prototype test campaigns were conducted at high-temperature flow facilities intended to simulate exhaust gas conditions and within the exhaust of vehicles mounted on a chassis dynamometer. Results from these tests demonstrated that the sensor prototype is fundamentally free of cross-interference with competing species in the exhaust stream, can achieve a 1 ppmv NO detection limit, and can be operated across the full range of thermodynamic conditions expected for typical vehicle exhausts. These features address the key technological drawbacks associated with electrochemical
The identification of vehicle noise is the basis for studying the acoustic characteristics of vehicles. In this paper, both excitation of noise sources and response of interior noise were identified. Firstly, a transfer path analysis (TPA) model was established to identify the excitation of noise sources, which includes vehicle main noise sources, such as engine, tire, exhaust pipe and muffler. Based on the operational signals and transfer function which were tested in the vehicle semi-anechoic room, the excitation of noise sources was identified using inverse matrix method. Identify result indicated that tires have higher excitation amplitude than engine in high frequency band. Therefore, the transfer path between the tire and the cabin, such as carpet and windshield, should be taken as the focus of acoustic performance improvement. By improving the acoustic material on the transfer path, the loss of sound in the transfer path will be increase. Secondly, the energy superposition
The given invention solves the problems associated with the growing greenhouse gases and electric mobility in Indian automobile market using design-thinking approach. It addresses the issue of air pollution, lack of charging infrastructure, limited range of electric vehicles, and high cost of travelling in IC engine vehicles. The problem statement of the project is selected through the process of design thinking. Data for the project is collected from the actual segment of people. The given invention displays the plug-in hybrid electric vehicle kit. The kit retrofits the conventional fuel engine vehicle into plug-in hybrid electric vehicle. As a result, the user can drive on electric mode and when the batteries are exhausted, the user can switch to fuel engine mode. Using the given technology, users can lower the tail pipe pollutants emitted from the vehicle. By using this technology, users can save 73.74% of cost per year
This paper redraws and shows the pressure volume Pv- diagram and the T-S diagram of the Carnot cycle, Otto engine, and turbocharged Zhou Engine. It imitates the thermodynamic analysis of steam or gas turbines, takes into account the transport-work, and rederives the ideal thermal efficiency formula of Otto engines, which is much different from the current one. It is found that the current thermodynamics of internal combustion (IC) engines neglected the transport-work and the entropy increase in the exhaust pipe, overvalued the ideal thermal efficiency, and is a wrong line in the temperature entropy (T-S) diagram. In particular, the entropy increase in the exhaust pipe hides and wastes a lot of mechanical energy, which the turbocharged Zhou Engine can recycle
This SAE Recommended Practice establishes the test procedure, environment, and instrumentation to be used for measuring the exterior exhaust sound level for passenger cars, multipurpose vehicles, and light trucks under stationary conditions providing a continuous measure of exhaust system sound level over a range of engine speeds. This document applies only to road vehicles equipped with an internal combustion engine. The method is designed to meet the requirements of simplicity as far as they are consistent with reproducibility of results under the operating conditions of the vehicle. It is within the scope of this document to measure the stationary A-weighted sound pressure level during: Measurements at the manufacturing stage Measurements at official testing stations Measurements at roadside testing It does neither specify a method to check the exhaust sound pressure level when the engine is operated at realistic load nor a method to check the exhaust sound pressure levels against a
With implementation of stringent BSVI emission norms and regulations like OBD-II on vehicle, it is essential to define the life of exhaust after treatment along with the vehicle. Diesel after treatment generally consists of DOC, DPF and SCR. Lubricating oil contains phosphorus and zinc which adversely affect the DOC. Unburned hydrocarbons (UNHBC) and SOF in tail pipe get accumulated in the DPF. This requires regeneration process where in, high temperatures in exhaust after treatment (EATS) burn the adsorbed Sulphur or phosphorus, thereby improving the conversion efficiencies. Repeated regenerations lead to ash accumulation in DPF and this reduces its capability for soot accumulation. Sulphur in the exhaust impacts SCR through NOx conversion. The present study analyzes the effect of (1) Chemical aging (2) Thermal aging on 3.77 liter diesel engine after treatment. A test cycle was prepared to run the durability for EATS. It consists of total normal running hours as well as cumulative
Short development cycles, less packaging space and stringent noise emission rules have increased the need of CAE usage and first time right design approach. Engine exhaust noise is the main contributor of automotive noise when vehicle speed is low to moderate. Exhaust noise contains tailpipe noise and shell radiation noise. As vehicle speed increases, contribution of flow noise and tire noise is comparatively at higher side. The cold end development engineer is responsible to design a muffler to meet tailpipe and shell radiation noise targets. Muffler shell stiffness is a key characteristic for deciding shell radiation noise. High intensity pulses of exhaust gas passes through the exhaust pipe and hits cold end from inside which causes shell vibration and respectively shell noise. There are several conventional methods available to improve shell stiffness, but all of them are not applicable for ‘double layered critically shaped mufflers’ and all of them are not cost-effective. The
As per current global trends, low tailpipe and evaporative emissions is a major focus area in automotive development. This has led to imposition of stringent emission limits on both tailpipe and evaporative emission norms. In the field of evaporative emissions, the fuel valves must meet zero-leak of fuel to canister requirement under different operating conditions. Corresponding sealing design iterations and evaluating the performance through lab testing is time and cost consuming. Present study considers FEA based sealing analysis considering elastomeric-plastic interface using ANSYS®. The designs are evaluated by comparing surface contact of seal with valve orifice. In present study, different combinations of shape, size of plastic and elastomeric parts, material stiffness, axis position of elastomeric & plastic parts and use of supporting structure for elastomeric parts were evaluated. A methodology is provided to optimize seal design to meet zero-leak (<0.05 ccm) of fuel
Engine exhaust noise and heat are significant sources of emissions in the environment. Engine exhaust systems are designed to minimize noise and heat while maintaining the necessary db levels and sound quality, as well as emissions in accordance with environmental regulations. Mufflers remain an integral portion of the IC engine arrangement are widely used in IC engine exhaust arrangements to reduce sound generated by engine exhaust gases as well as to reduce heat. The most efficient way to reduce noise and heat is to install a exhaust muffler in the engine tail pipe. The aim of our project is to design and analysis an engine exhaust muffler for reducing exhaust noise and heat. Appropriate design and analysis would aid in the reduction of noise and heat, while at the same time, the backpressure generated by the muffler should not affect the engine's efficiency. 3D models are developed in Solid Works software before being exported to ANSYS FLUENT CFD software for review in this report
An afterburner-assisted turbocharged single-cylinder 425 cc two-stroke SI-engine is described in this simulation study. This engine is intended as a Backup Range Extender (REX) application for heavy-duty battery electric vehicles (BEV) when external electric charging is unavailable. The 425 cc engine is an upscaled version of a 125 cc port-injected engine [26] which demonstrated that the selected technology could provide a specific power level of 400 kW/L and the desired 150 kW in a heavy duty BEV application. The 425 cc single cylinder two-stroke engine is an existing engine as one half of a 850 cc snowmobile engine. This simulation study includes upscaling of the swept volume, impact on engine speed and gas exchange properties. In the same way as for the 125cc engine [26], the exhaust gases reaches the turbine through a tuned exhaust pipe and an afterburner or oxidation catalyst. The intent with the afterburner is to convert some of the air and hydrocarbons (HC) to heat to provide
The objective of this research was to mitigate urea-derived deposit formation within selective catalytic reduction (SCR) aftertreatment systems by application of specific superhydrophobic coatings to exhaust pipe surfaces. Coatings were applied using a plasma immersion ion processing (PIIP)-like process denoted LotusFlo™. This process utilizes high DC-impulse power waveforms in conjunction with appropriate chemical precursors to generate coatings suited to a specific application. For the present research, organosiloxane (Lotus-130) and fluorinated organosiloxane (Lotus-131) coated surfaces were evaluated. Deposit accumulation studies were executed using the Exhaust Composition Transient Operation LaboratoryTM (ECTO-LabTM) burner system. An in-situ imaging system was installed in the ECTO-Lab to observe differences in the deposit formation process between coated and uncoated exhaust pipes. The adhesion strength of urea to each of the LotusFlo surfaces was quantified using the Shear and
Particulate matter (PM) and NOX are two major pollutants generated by diesel engines. Modern diesel aftertreatment systems include selective catalytic reduction (SCR) technology that helps reduce tailpipe NOX emissions when coupled with diesel exhaust fluid (DEF/urea) injection. However, this process also results in the formation of urea derived byproducts that can influence non-volatile particle number (PN) measurement conducted in accordance with the European Union (EU) Particle Measurement Program (PMP) protocol. In this program, an experimental investigation of the impact of DEF injection on tailpipe PN and its implications for PMP compliant measurements was conducted using a 2015 model year 6.7 L diesel engine equipped with a diesel oxidation catalyst, diesel particulate filter and SCR system. Open access to the engine controller was available to manually override select parameters. Ammonia-to-NOX (ANR) ratio was varied to understand the impact of urea injection rate on measured
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