Three-Dimensional Catalytic Regeneration Modeling of SiC Diesel Particulate Filters

2005 ◽  
Vol 128 (2) ◽  
pp. 421-433 ◽  
Author(s):  
George Pontikakis ◽  
Anastassios Stamatelos
Keyword(s):  
Three Dimensional ◽  
Particulate Filter ◽  
Particulate Emissions ◽  
Three Dimensional Model ◽  
Standard Equipment ◽  
Efficient System ◽  
Diesel Particulate ◽  
Filter Performance ◽  
D Model ◽  
Diesel Filter

Increasingly stringent diesel particulate emissions standards have reestablished international interest in diesel filters, whose first series application dates back to 1985. Modern diesel engine technology, with computerized engine management systems and advanced, common rail injection systems, needs to be fully exploited to support efficient and durable diesel filter systems with catalytic aids, as standard equipment in passenger cars. Efficient system and components’ optimization requires the use of mathematical models of diesel filter performance. The three-dimensional model for the regeneration of the diesel particulate filter presented in this paper has been developed as an engineering tool for the detailed design optimization of SiC diesel filters of modular structure. The 3-D modeling is achieved by interfacing an existing 1-D model to commercial finite element method software for the computation of the 3-D temperature field within the whole filter assembly, including the adhesive of the filter blocks, the insulation mat, and the metal canning. The 3-D model is applied to real-world component optimization studies of diesel filter systems.

3-D Model of Proton Exchange Membrane Fuel Cells

2000 ◽  
Author(s):  
Tianhong Zhou ◽  
Hongtan Liu
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Pem Fuel Cell ◽  
Proton Exchange ◽  
Three Dimensional Model ◽  
Chemical Reaction Kinetics ◽  
Fuel Cell Performance ◽  
D Model

Abstract A comprehensive three-dimensional model for a proton exchanger membrane (PEM) fuel cell is developed to evaluate the effects of various design and operating parameters on fuel cell performance. The geometrical model includes two distinct flow channels separated by the membrane and electrode assembly (MEA). This model is developed by coupling the governing equations for reactant mass transport and chemical reaction kinetics. To facilitate the numerical solution, the full PEM fuel cell was divided into three coupled domains according to the flow characteristics. The 3-D model has been applied to study species transport, heat transfer, and current density distributions within a fuel cell. The predicated polarization behavior is shown to compare well with experimental data from the literature. The modeling results demonstrate good potential for this computational model to be used in operation simulation as well as design optimization.

Experimental study of lubricant-derived ash effects on diesel particulate filter performance

2019 ◽  
pp. 146808741987457 ◽  
Author(s):  
Jun Zhang ◽  
Yanfei Li ◽  
Victor W Wong ◽  
Shijin Shuai ◽  
Jinzhu Qi ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Diesel Particulate Filter ◽  
Particulate Filter ◽  
Maximum Temperature ◽  
Particle Emissions ◽  
Diesel Particulate ◽  
Particulate Filters ◽  
Filter Performance ◽  
Soot Loading ◽  
Active Regeneration

Diesel particulate filters are indispensable for diesel engines to meet the increasingly stringent emission regulations. A large amount of ash would accumulate in the diesel particulate filter over time, which would significantly affect the diesel particulate filter performance. In this work, the lubricant-derived ash effects on diesel particulate filter pressure drop, diesel particulate filter filtration performance, diesel particulate filter temperature field during active regeneration, and diesel particulate filter downstream emissions during active regeneration were studied on an engine test bench. The test results show that the ash accumulated in the diesel particulate filter would decrease the diesel particulate filter pressure drop due to the “membrane effect” when the diesel particulate filter ash loading is lower than about 10 g/L, beyond which the diesel particulate filter pressure drop would be increased due to the reduction of diesel particulate filter effective volume. The ash loaded in the diesel particulate filter could significantly improve the diesel particulate filter filtration efficiency because it would fill the pores of diesel particulate filter wall. The diesel particulate filter peak temperature during active regeneration is consistent with the diesel particulate filter initial actual soot loading density prior to regeneration at various diesel particulate filter ash loading levels, while the diesel particulate filter maximum temperature gradient would increase with the diesel particulate filter ash loading increase, whether the diesel particulate filter is regenerated at the same soot loading level or the same diesel particulate filter pressure drop level. The ash accumulation in the diesel particulate filter shows little effects on diesel particulate filter downstream CO, total hydrocarbons, N2O emissions, and NO2/NO x ratio during active regeneration. However, a small amount of SO2 emissions was observed when the diesel particulate filter ash loading is higher than 10 g/L. The ash accumulated in the diesel particulate filter would increase the diesel particulate filter downstream sub-23 nm particle emissions but decrease larger particle emissions during active regeneration.

scholarly journals A cross-validated three-dimensional model of an englacial and subglacial drainage system in a High-Arctic glacier

2020 ◽  
Vol 66 (256) ◽  
pp. 278-290
Author(s):  
Lena U. Hansen ◽  
Jan A. Piotrowski ◽  
Douglas I. Benn ◽  
Heidi Sevestre
Keyword(s):  
Three Dimensional ◽  
Drainage System ◽  
High Arctic ◽  
Water Drainage ◽  
Three Dimensional Model ◽  
Closure Mechanism ◽  
Ground Penetrating ◽  
Arctic Glacier ◽  
D Model ◽  
Englacial Drainage

AbstractRecent speleological surveys of meltwater drainage systems in cold and polythermal glaciers have documented dynamic englacial and in some cases subglacial conduits formed by the ‘cut-and-closure’ mechanism. Investigations of the spatial distribution of such conduits often require a combination of different methods. Here, we studied the englacial drainage system in the cold glacier Longyearbreen, Svalbard by combining speleological exploration of a 478 m long meltwater conduit with a high-resolution ground penetrating radar (GPR) survey with two different centre-frequencies (25 and 100 MHz). The results yielded a 3-D documentation of the present englacial drainage system. The study shows that the overall form of englacial conduits can be detected from velocity−depth converted GPR data, and that the 3-D model can facilitate a method to pinpoint the reflections in a radargram corresponding with the englacial drainage system, although fine detail cannot be resolved. Visible reflections approximately parallel to the mapped englacial water drainage system likely result from sediment incorporated in the ice or from abandoned parts of the englacial drainage system.

Experimental Study of Thermal Aging on Catalytic Diesel Particulate Filter Performance

2013 ◽  
Vol 6 (2) ◽  
pp. 688-698 ◽  
Author(s):  
Dimitrios Zarvalis ◽  
Dimitrios Pappas ◽  
Souzana Lorentzou ◽  
Theofilaktos Akritidis ◽  
Leonidas Chasapidis ◽  
...  
Keyword(s):  
Experimental Study ◽  
Thermal Aging ◽  
Diesel Particulate Filter ◽  
Particulate Filter ◽  
Diesel Particulate ◽  
Filter Performance

The Three-Dimensional Model for a Community

2022 ◽  
pp. 521-534
Author(s):  
Gregory B. White ◽  
Natalie Sjelin
Keyword(s):  
Cyber Security ◽  
Action Plan ◽  
Three Dimensional ◽  
Maturity Model ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Initial Development ◽  
The Creation ◽  
D Model

The community cyber security maturity model (CCSMM) was designed and developed to provide communities with an action plan to build a viable and sustainable cybersecurity program focused on improving their overall cybersecurity capability. Not long after the initial development of the model, it was realized that there are intertwined relationships that needed to be addressed. This drove the creation of the three-dimensional model broadening the scope to include individuals, organizations, communities, states, and the nation. This chapter will provide an overview of the development and importance of the 3-D model and will describe the scope areas that were included.

Evaluation of an approximate method for incorporating floating docks in harbor wave prediction models

2005 ◽  
Vol 32 (6) ◽  
pp. 1082-1092 ◽  
Author(s):  
Dongcheng Li ◽  
Vijay Panchang ◽  
Zhaoxiang Tang ◽  
Zeki Demirbilek ◽  
Jerry Ramsden
Keyword(s):  
Prediction Models ◽  
Three Dimensional ◽  
Wave Model ◽  
Three Dimensional Model ◽  
Transmission Coefficients ◽  
Mild Slope Equation ◽  
Wide Range ◽  
Floating Objects ◽  
Floating Breakwaters ◽  
D Model

Computer models based on the two-dimensional (2-D) elliptic mild-slope equation are nowadays routinely used in harbor engineering applications. However, structures like floating breakwaters and docks, which are often encountered in the modeling domain, render the problem for locally three-dimensional model and hence are problematic to incorporate in a 2-D model. Tsay and Liu (Applied Ocean Research. 1983. Vol 5(1): 30–37) proposed a highly simplified but approximate approach that does not violate the overall two dimensionality of the problem. The validity of their approach is examined in detail, and it is found that although their approximation provides results with the correct trend, the actual solutions deviate considerably from the theoretical solutions. We have developed correction factors that may be used to produce more reliable results using the framework of Tsay and Liu. Application of the resulting method to a harbor in Alaska shows that docks in the harbor distort the wave field considerably and create a reflective pattern that has the potential to affect navigation safety in some areas. A by-product of this paper consists of plots of transmission coefficients for waves propagating past rectangular and cylindrical floating objects of infinite extent for a wide range of conditions encountered in practice. Such transmission coefficients are at present readily available in the published literature for selected cases only.Key words: wave, model, mild slope, equation, floating breakwater, dock, marina, harbor.

Real-time particulate emissions rates from active and passive heavy-duty diesel particulate filter regeneration

2019 ◽  
Vol 680 ◽  
pp. 132-139 ◽  
Author(s):  
Jeremy D. Smith ◽  
Chris Ruehl ◽  
Mark Burnitzki ◽  
Wayne Sobieralski ◽  
Robert Ianni ◽  
...  
Keyword(s):  
Real Time ◽  
Diesel Particulate Filter ◽  
Particulate Filter ◽  
Particulate Emissions ◽  
Heavy Duty ◽  
Diesel Particulate ◽  
Filter Regeneration ◽  
Heavy Duty Diesel

scholarly journals Assessment of Gaseous and Particulate Emissions of a Euro 6d-Temp Diesel Vehicle Driven >1300 km Including Six Diesel Particulate Filter Regenerations

Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 645 ◽  
Author(s):  
Victor Valverde ◽  
Barouch Giechaskiel
Keyword(s):  
Average Distance ◽  
Short Interval ◽  
Background Level ◽  
Particulate Filter ◽  
N2o Emissions ◽  
Particulate Emissions ◽  
Nox Emissions ◽  
Diesel Particulate ◽  
The Road ◽  
On The Road

Diesel-fueled vehicles have classically had high particulate and NOx emissions. The introduction of Diesel Particulate Filters (DPFs) and Selective Catalytic Reduction for NOx (SCR) systems have decreased the Particle Number (PN) and NOx emissions, respectively, to very low levels. However, there are concerns regarding the emissions released during the periodic DPF regenerations, which are necessary to clean the filters. The absolute emission levels and the frequency of the regenerations determine the contribution of regenerations, but where they happen (city or highway) is also important due to different contributions to human exposure. In this study, we measured regulated and non-regulated emissions of a Euro 6d-temp vehicle both in the laboratory and on the road. PN and NOx emissions were similar in the laboratory and on-the road, ranging around 1010 p/km and 50 mg/km, respectively. Six regeneration events took place during the 1300 km driven, with an average distance between regeneration events of only 200 km. During regeneration events, the laboratory limits for PN and NOx, although not applicable, were exceeded in one of the two measured events. However, the on-road emissions were below the applicable not-to-exceed limits when regenerations occurred. The weighted PN and NOx emissions over the regeneration distance were approximately two times below the applicable limits. The N2O emissions were <14 mg/km and NH3 at instrument background level (<1 ppm), reaching 8 ppm only during regeneration. The results of this study indicate that due to the short interval between regenerations, studies of diesel vehicles should report the emissions during regeneration events.

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