Heat release analysis for rapid compression machines: Challenges and opportunities

Goldsborough, S. Scott; Santner, Jeffrey; Kang, Dongil; Fridlyand, Aleksandr; Rockstroh, Toby; Jespersen, Mads C.

doi:10.1016/j.proci.2018.05.128

Cited by 32 publications

(19 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figures 5 and 6 show the experimental and simulated HRRs prior to the main ignition event plotted against the aHR and time from the maximum pressure gradient, respectively, at temperatures of 710, 770, and 830 K. LTHR is common in degenerately branched systems and describes exothermic events that occur before the main stage of heat release, which describes the autoignition event 79 . LTHR is indicated by a relatively sharp peak in HRR and an associated rise in pressure, which also produces a visible CH 2 O* chemiluminescence and is considered to be chemically due to the decomposition of ketohydroperoxides to produce multiple OH radicals 54 . In some cases, LTHR may be followed by an intermediate stage of heat release (ITHR), which also occurs before the autoignition event.…”

Section: Resultsmentioning

confidence: 99%

“…Goldsborough et al 54 . have shown in previous work that HRA can be applied effectively to RCM experiments, facilitating the investigation of low‐temperature heat release behavior for a wide range of thermodynamic conditions.…”

Section: Methodsmentioning

confidence: 99%

“…Nonreactive RCM tests provide pressure (and volume) histories, which are applied to empirically account for heat losses from the RCM system over the course of a test. By applying Equation (2) under these conditions, and assuming that the piston trajectory is identical between both reactive and nonreactive cases, it can be shown that 54

\begin{matrix} true \\ right HRR & = & left \frac{γ}{γ - 1} \frac{d V}{d t} ((), P - P_{nr}) + \frac{1}{γ - 1} V ((), \frac{d P}{d t} - \frac{d P}{d t} |_{nr}) \\ left - \frac{P V}{{((), γ - 1)}^{2}} ((), \frac{d γ}{d t} - \frac{d γ}{d t} |_{nr}), \end{matrix}

…”

Section: Methodsmentioning

confidence: 99%

“…Due to an array of challenges concerning the use of RCM, such as significant heat losses, fuel transfer into piston crevices, and the difficulty in acquiring suitable transducer measurements, HRA has not traditionally been applied to RCM studies. However, recent studies have developed a method through which HRA may be applied to RCM experimental data 54 . This technique provides an avenue for significant further exploration of fuels and their ignition behavior, including the detection of inhomogeneous ignition events, the quantification of initial exothermicity, and the improvement of chemical kinetic knowledge and models.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

An experimental and kinetic modeling study of the ignition delay and heat release characteristics of a five component gasoline surrogate and its blends with iso‐butanol within a rapid compression machine

Michelbach

Tomlin

2021

Int J of Chemical Kinetics

View full text Add to dashboard Cite

This study investigates the performance of a five component gasoline surrogate (iso‐octane, toluene, n‐heptane, 1‐hexene, and ethanol) in representing the ignition delay time (IDT) behavior of gasoline (reference gasoline PR5801—research octane number 95.4, motor octane number 86.6), at conditions of 675–870 K, 20 bar, and Ф = 1 (stoichiometric) within a rapid compression machine (RCM). Experimentally, the surrogate produces a good representation of the ignition behavior of the gasoline at these conditions, displaying a similar IDT profile. The influence of blending with iso‐butanol on the surrogate's ignition delay behavior is also investigated, at blends from 5% to 70% of iso‐butanol by volume. The surrogate continues to produce a reasonable representation of the experimental IDTs of gasoline and iso‐butanol blends, except under a high degree of iso‐butanol blending (50% iso‐butanol), where the surrogate produced longer IDTs, particularly at temperatures below 740 K. Blends of 5% and 10% iso‐butanol produce IDTs shorter than that of any other blend, including the “neat” surrogate, at temperatures of 740–770 and 830 K, respectively. Kinetic modeling of RCM IDTs is performed using CHEMKIN‐PRO (Reaction Design: San Diego, CA, 2011) and a combined mechanism of the Sarathy et al. butanol isomers mechanism (Progress in Energy and Combustion Science 2014; 44: 40–102) and Lawrence Livermore National Laboratories “Gasoline Surrogate” mechanism (Proceedings of the Combustion Institute 2011; 33(1): 193–200). The model produces good IDT predictions below 740 K but overpredicts reactivity in the negative temperature coefficient region. Heat release rate analysis is conducted for experimental and modeling results to investigate low‐temperature heat release (LTHR) behavior. Simulations largely fail to accurately reproduce this behavior. This analysis, combined with local OH and brute force Δhf sensitivity analyses, indicates the significance of LTHR in the determination of IDTs and provides RCM heat release rates for future model validation.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

\begin{matrix} true \\ right HRR & = & left \frac{γ}{γ - 1} \frac{d V}{d t} ((), P - P_{nr}) + \frac{1}{γ - 1} V ((), \frac{d P}{d t} - \frac{d P}{d t} |_{nr}) \\ left - \frac{P V}{{((), γ - 1)}^{2}} ((), \frac{d γ}{d t} - \frac{d γ}{d t} |_{nr}), \end{matrix}

…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

An experimental and kinetic modeling study of the ignition delay and heat release characteristics of a five component gasoline surrogate and its blends with iso‐butanol within a rapid compression machine

Michelbach

Tomlin

2021

Int J of Chemical Kinetics

View full text Add to dashboard Cite

show abstract

“…The validation criterion of the model predictions against experiments is pre-flame stage timing τ I . Goldsborough [5] has shown that this stage is over when the magnitude of current pressure exceeds the initial by one more than 5 %.…”

Section: A Kinetic Mechanismmentioning

confidence: 99%

The single-zone numerical model of homogeneous charge compression ignition engine performance

Fedyanov

Itkis

Kuzmin

et al. 2017

IOP Conf. Ser.: Mater. Sci. Eng.

View full text Add to dashboard Cite

Abstract.The single-zone model of methane-air mixture combustion in the Homogeneous Charge Compression Ignition engine was developed. First modeling efforts resulted in the selection of the detailed kinetic reaction mechanism, most appropriate for the conditions of the HCCI process. Then, the model was completed so as to simulate the performance of the fourstroke engine and was coupled by physically reasonable adjusting functions. Validation of calculations against experimental data showed acceptable agreement. IntroductionHomogeneous Charge Compression Ignition (HCCI) is currently under widespread investigation. To limit the speed of combustion, lean mixtures are used. If the mixture is too rich, the pressure rises too rapid and generates knock-related problems. On the other side, lean equivalence ratios of the fuel/air mixture inducted into the cylinder provide low nitric oxides (NO x ) and particulate emissions, low fuel consumption. The HCCI process seems promising when running the engine using gas as fuel, especially using natural gas.However, several problems with the HCCI combustion concept reappear throughout the majority of investigations -two combustion control aspects. First, the ignition event and the ignition timing are not controlled. Second, the rate of heat release is not controlled too. It occurs due to insufficient understanding of HCCI technology. In conjunction with extensive experimental researches, computational models provide a good basis for exploring the HCCI combustion phenomena. Yet a direct numerical simulation of fluid mechanics combined with the detailed chemical kinetic model is computationally complex. The typical method of the solution of the problem is simplification either in fluid mechanics or in the chemistry part of the model. An example of the latter approach is the singlezone model, developed in Volgograd State Technical University. The simulation of chemical kinetics is based on the law of mass action and the Arrhenius rate expression. This approach enables one to explore numerically the influence of the inlet air-fuel ratio, the initial mixture temperature and the incylinder pressure on the ignition timing that is directly dependent on the pre-flame chemical reactions.In this paper, we present the investigation arranged as follows. The first section is the development of the first stage of the ignition event model -self ignition in the constant volume adiabatic reactor. The results obtained made it possible to choose the most acceptable kinetic reaction mechanism of methane burning. The second section is the development of the one-zone numerical model of the HCCI running process incorporating the kinetic model mentioned above. The third -the analyses of the preliminary results of the study, related to the validation of the model predictions against

show abstract

Oxidation and pyrolysis of methyl propyl ether

Johnson

Nimlos

Ninnemann

et al. 2021

Int J of Chemical Kinetics

Self Cite

View full text Add to dashboard Cite

The ignition, oxidation, and pyrolysis chemistry of methyl propyl ether (MPE) was probed experimentally at several different conditions, and a comprehensive chemical kinetic model was constructed to help understand the observations, with many of the key parameters computed using quantum chemistry and transition state theory. Experiments were carried out in a shock tube measuring time variation of CO concentrations, in a flow tube measuring product concentrations, and in a rapid compression machine (RCM) measuring ignition delay times. The detailed reaction mechanism was constructed using the Reaction Mechanism Generator software. Sensitivity and flux analyses were used to identify key rate and thermochemical parameters, which were then computed using quantum chemistry to improve the mechanism. Validation of the final model against the 1–20 bar 600–1500 K experimental data is presented with a discussion of the kinetics. The model is in excellent agreement with most of the shock tube and RCM data. Strong non‐monotonic variation in conversion and product distribution is observed in the flow‐tube experiments as the temperature is increased, and unusually strong pressure dependence and significant heat release during the compression stroke is observed in the RCM experiments. These observations are largely explained by a close competition between radical decomposition and addition to O2 at different sites in MPE; this causes small shifts in conditions to lead to big shifts in the dominant reaction pathways. The validated mechanism was used to study the chemistry occurring during ignition in a diesel engine, simulated using Ignition Quality Test (IQT) conditions. At the IQT conditions, where the MPE concentration is higher, bimolecular reactions of peroxy radicals are much more important than in the RCM.

show abstract

Heat release analysis for rapid compression machines: Challenges and opportunities

Cited by 32 publications

References 38 publications

An experimental and kinetic modeling study of the ignition delay and heat release characteristics of a five component gasoline surrogate and its blends with iso‐butanol within a rapid compression machine

An experimental and kinetic modeling study of the ignition delay and heat release characteristics of a five component gasoline surrogate and its blends with iso‐butanol within a rapid compression machine

The single-zone numerical model of homogeneous charge compression ignition engine performance

Oxidation and pyrolysis of methyl propyl ether

Contact Info

Product

Resources

About