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
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
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
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
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