Prediction of transient nitric oxide in diesel exhaust

Chan, Siew Hwa; He, Y; Sun, Jingli

doi:10.1243/0954407991526892

Cited by 17 publications

(17 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During the last three decades, diesel engine simulation and experimental investigation have paved the way for an in-depth study of transient operation [1][2][3][4][5][6][7]. However, the majority of research has focused so far on issues concerning thermodynamic modeling because of their direct impact on heat release prediction and consequently performance and pollutants emissions.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Various Dynamic Issues During Transient Operation of Turbocharged Diesel Engine with Special Reference to Friction Development

Rakopoulos¹,

Giakoumis²,

Dimaratos³

2007

SAE Technical Paper Series

View full text Add to dashboard Cite

The modeling of transient turbocharged diesel engine operation appeared in the early seventies and continues to be in the focal point of research, due to the importance of transient response in the everyday operating conditions of engines. The majority of research has focused so far on issues concerning thermodynamic modeling, as these directly affect heat release predictions and consequently performance and pollutants emissions. On the other hand, issues concerning the dynamics of transient operation are often disregarded or over-simplified, possibly for the sake of speeding up program execution time. In the present work, an experimentally validated transient diesel engine simulation code is used to study and evaluate the importance of such dynamic issues. First of all, the development of various forces (piston, connecting rod, crank and main crankshaft bearings) is computed and illustrated in order to evaluate the importance of abrupt load increases on the bearings durability. The usual approximation of the connecting rod being considered as equivalent to two masses (one reciprocating with the piston and the other rotating with the crank) is put into test. The same holds true for another usual assumption, i.e. the crankshaft being considered as sufficiently rigid. In this work, the engine crankshaft is analyzed in detail with the instantaneous torsional angle between engine and load taken into account. Thus, details are provided concerning the development of crankshaft torsional deformation during transients. The main part of the paper focuses on the development and contribution of various friction components during turbocharged diesel engine transients. This is accomplished via the use of a recently proposed detailed friction model. Mean fmep (friction mean effective pressure) modeling is found to considerably underestimate actual friction around firing TDC, leading to lower speed droops for abrupt load increases. The piston rings assembly contribution is dominant for the particular engine, due to its high number of piston rings and its relatively low crankshaft speed. The model can be used to investigate such interesting cases as the effect of engine oil temperature on engine transient response, or the variation of oil film thickness during a cycle or a transient event.

show abstract

Section: Introductionmentioning

confidence: 99%

Evaluation of Various Dynamic Issues During Transient Operation of Turbocharged Diesel Engine with Special Reference to Friction Development

Rakopoulos¹,

Giakoumis²,

Dimaratos³

2007

SAE Technical Paper Series

View full text Add to dashboard Cite

show abstract

“…[72][73][74][75][76][77][78][79][80][81][82][83] approach have been developed. The studies have concentrated on interesting issues such as effect of VGT [84][85][86], turbocharger match [87], thermal shock in engine structures [88], governor operation [89,90], exhaust emissions [91][92][93][94][95][96][97][98][99], vehicle cooling system [100], effect of compressor surging [101][102][103][104][105][106][107], electrically assisted turbocharging [108][109][110][111], vehicle performance [112][113][114][115][116], variable valve timing [117], sequential turbocharging [118] and marine diesel engine applications …”

Section: Historical Overviewmentioning

confidence: 99%

“…It leaves, however, unanswered the question about the development and prediction of exhaust emissions which is nowadays a key issue. For the latter, a solution was attempted by two-zone [93], or multi-zone models [95,[97][98][99], with moderate success.…”

Section: Filling and Emptying Approachmentioning

confidence: 99%

“…An alternative approach is to use an "hysteresis" (time lag due to thermal inertia) expression to update the wall temperature at each consecutive cycle, which changes as a result of the increase in fueling and/or speed [22,46,98]. This approach is based on the well known fact that the update of cylinder wall temperature is notably delayed compared to changes in fueling.…”

Section: Heat Transfermentioning

confidence: 99%

“…Most researchers assume that these curves hold true for transient conditions too, perhaps by imposing a time delay [14,98]. Cui et al [99] applied linear, steady-state approximations for the injection timing, duration and injection pattern into the transient simulation code.…”

Section: Frictionmentioning

confidence: 99%

See 2 more Smart Citations

Review of Thermodynamic Diesel Engine Simulations under Transient Operating Conditions

Rakopoulos¹,

Giakoumis²

2006

SAE Technical Paper Series

View full text Add to dashboard Cite

Study and modeling of transient operation is an important scientific objective. This is due to the fact that the majority of daily vehicle driving conditions involve transient operation, with non-linear situations experienced during engine transients. Thus, proper interconnection is needed between engine, governor, fuel pump, turbocharger and load. This paper surveys the publications available in the open literature concerning diesel engine simulations under transient operating conditions. Only those models that include both full engine thermodynamic calculations and dynamic powertrain modeling are taken into account, excluding those that focus on control design and optimization. Most of the attention is concentrated to the simulations that follow the filling and emptying modeling approach. A historical overview is given covering, in more detail, research groups with continuous and consistent study of transient operation. One of the main purposes of this paper is to summarize basic equations and modeling aspects concerning in-cylinder calculations, friction, turbocharger, engine dynamics, governor, fuel pump operation, and exhaust emissions during transients. The various limitations of the models are discussed together with the main aspects of transient operation (e.g. turbocharger lag, combustion and friction deterioration), which diversify it from the steady-state. Some of the most important findings in the field during the last 30 years are presented and discussed. The survey extends to special cases of transient diesel engine simulation, such as second-law analysis, response when the turbocharger compressor experiences surge, and whole vehicle performance. Several methods of improving transient response are also mentioned, based on the various simulations. An easy-to-read tabulation of all research groups dealing with the subject, that includes details about each model developed and engines/parameters studied, is also provided at the end of the paper.

show abstract

Evaluation of the effect of engine, load and turbocharger parameters on transient emissions of diesel engine

Rakopoulos

Dimaratos

Giakoumis

et al. 2009

Energy Conversion and Management

View full text Add to dashboard Cite

Prediction of transient nitric oxide in diesel exhaust

Cited by 17 publications

References 12 publications

Evaluation of Various Dynamic Issues During Transient Operation of Turbocharged Diesel Engine with Special Reference to Friction Development

Evaluation of Various Dynamic Issues During Transient Operation of Turbocharged Diesel Engine with Special Reference to Friction Development

Review of Thermodynamic Diesel Engine Simulations under Transient Operating Conditions

Evaluation of the effect of engine, load and turbocharger parameters on transient emissions of diesel engine

Contact Info

Product

Resources

About