Three–Dimensional Transient Elastic Thermal Stress Field During Diesel Particulate Filter Regeneration

A displacement based 3D finite element model is developed to simulate thermal stress induced by high temperature and temperature gradient during diesel particulate filter (DPF) regeneration. The temperature field predicted by 3D regeneration model from previous work is used as input. This finite element model agrees well with commercial software. It is a self-contained package capable of implementing meshing body, assembling global stiffness matrix and solving final equilibrium equations. Numerical simulation indicates that it is peak temperature rather than temperature gradient that leads to higher compressive thermal stress during regeneration. The maximum stress always appears at the channel corner located at the end of DPF. Parametric studies are performed to investigate the effects of DPF design on pressure drop, regeneration temperature, and thermal stress. This model provides insights into the complicated DPF working mechanism, and it can be used as design tools to reduce filter pressure drop while enhance its short term and long term durability.

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

International Journal of Engine Research ◽

10.1177/1468087419874577 ◽

2019 ◽

pp. 146808741987457 ◽

Cited By ~ 1

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.

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Mechanical Analysis of Porous Concrete Base in Asphalt Pavement

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.443-444.751 ◽

2012 ◽

Vol 443-444 ◽

pp. 751-756

Author(s):

Li Jun Suo ◽

Xia Guang Hu

Keyword(s):

Finite Element ◽

Thermal Stress ◽

Finite Element Model ◽

Design Method ◽

Asphalt Pavement ◽

Element Model ◽

Three Dimension ◽

Porous Concrete ◽

Finite Element Software ◽

Concrete Base

In China, it is fact that porous concrete base has been used in the construction of asphalt pavement in recent years because porous concrete base has good performance. However, Reasonable design method has not been put forward so far. Therefore, it is necessary to analyze load stress and thermal stress of asphalt pavement which includes porous concrete base in order to put forward theoretical basis for pavement design method. In the paper, three–dimension finite element model of asphalt pavement, which includes porous concrete base and asphalt surface, is created for the purpose of studying load stress and thermal stress of porous concrete base in asphalt pavement. Based on numerical method of three–dimension finite element model, finite element software, such as ANSYS, is employed to study load stress and thermal stress of porous concrete base in asphalt pavement. After that, the effect of different factors on stress is studied, and the factors include thickness of surface, thickness of base and ratio of base’s modulus to foundation’s modulus. Finally, calculation results for stress are compared with each other, and it shows that load stress of porous concrete base decreases with increase of base’s thickness, while thermal stress of porous concrete base increases with increase of base’s thickness. Load stress and thermal stress of porous concrete base decrease with increase of surface’s thickness. Load stress and thermal stress of porous concrete base increase with increase of ratio of base’s modulus to foundation’s modulus.

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Advanced Diesel Particulate Filter Design for Lifetime Pressure Drop Solution in Light Duty Applications

10.4271/2007-01-0042 ◽

2007 ◽

Cited By ~ 8

Author(s):

Achim Heibel ◽

Rajesh Bhargava

Keyword(s):

Pressure Drop ◽

Diesel Particulate Filter ◽

Filter Design ◽

Particulate Filter ◽

Diesel Particulate ◽

Light Duty

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Experimental Analysis of Sudden Pressure Increase Phenomenon by Real-Time Internal Observation of Diesel Particulate Filter

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4033061 ◽

2016 ◽

Vol 138 (10) ◽

Cited By ~ 1

Author(s):

Rui Fukui ◽

Yuki Okamoto ◽

Masayuki Nakao

Keyword(s):

Particulate Matter ◽

Pressure Drop ◽

Diesel Particulate Filter ◽

Operating Conditions ◽

Particulate Filter ◽

Exhaust Gas ◽

Visualization Method ◽

Diesel Particulate ◽

Wide Perspective ◽

Deposit Layer

As a way of reducing the amount of particulate matter (PM) contained in the exhaust gas, diesel particulate filter (DPF) is widely used. To keep the condition of DPF normal and effective, estimation of the amount of PM deposits in the DPF is important. The estimation is mainly conducted based on the value of pressure drop across the DPF. Occasionally, the value of the pressure drop rises suddenly and it leads to overestimation of the amount of PM deposits. In order to elucidate the cause of the sudden pressure drop increase phenomenon, this paper first reveals the engine operating conditions which invoke this phenomenon. The authors also have developed a visualization method to realize the wide-perspective internal observation of the DPF. The observation experiment has been conducted with a commercial engine and DPF under the revealed conditions. Experimental results make clear that the phenomenon is caused by PM deposit layer collapse and channel plugging.

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3-D Transient Elastic Thermal Stress Field during Diesel Particulate Filter Regeneration

10.4271/2007-01-1141 ◽

2007 ◽

Cited By ~ 1

Author(s):

Zhenhua Guo ◽

Zhaoyan Zhang ◽

Wen Peng

Keyword(s):

Thermal Stress ◽

Stress Field ◽

Diesel Particulate Filter ◽

Particulate Filter ◽

Diesel Particulate ◽

Filter Regeneration ◽

Thermal Stress Field

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Effect of Steam Turbine Rotor Notch Fillet Radius on Stress and Deformation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.860-863.1770 ◽

2013 ◽

Vol 860-863 ◽

pp. 1770-1781

Author(s):

Dong Mei Ji ◽

M. H. Herman Shen ◽

Shi Hua Yang ◽

Gang Xia

Keyword(s):

Finite Element ◽

Thermal Stress ◽

Finite Element Model ◽

Steam Turbine ◽

Element Model ◽

Turbine Rotor ◽

Critical Value ◽

Steam Turbine Rotor ◽

Fillet Radius ◽

Start Up

A thorough investigation on the effect of a 320MW steam turbine rotor notch fillet radius on thermal and mechanical stresses during start up is presented. The approach consists of a shape design and analysis procedure which incorporates a finite element model. The finite element model is used to characterize the radius of the rotor notch fillet for ensuring the designed thermal and mechanical stress state/pattern and associated deflection during start-up. The results indicate that the notch fillet radius r has significant impact on the total stress of the rotor, in particular on thermal stress. It is determined that the thermal stress is decreased as the notch fillet radius r increases to a critical value. However, the thermal stress becomes saturated as the radius is increased to values larger than the critical value. The results also indicate that the rotor notch fillet radius has little effect on the deflection of the rotor during start-up. This investigation could be very useful to designers for construction of the design guidelines for steam turbine rotors.

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