Numerical study of wall heat transfer inside a combustion chamber under conventional diesel combustions and low temperature combustion conditions

2019 ◽  
Author(s):  
Mongkol Kaewbumrung ◽  
Chalermpol Plengsa-ard
Keyword(s):  
Heat Transfer ◽  
Low Temperature ◽  
Combustion Chamber ◽  
Numerical Study ◽  
Low Temperature Combustion ◽  
Wall Heat Transfer ◽  
Temperature Combustion

Modeling Soot Formation Using Reduced PAH Chemistry in n-Heptane Lifted Flames With Application to Low Temperature Combustion

2008 ◽  
Author(s):  
Gokul Vishwanathan ◽  
Rolf D. Reitz
Keyword(s):  
Low Temperature ◽  
Soot Formation ◽  
Numerical Study ◽  
Low Temperature Combustion ◽  
Constant Volume Chamber ◽  
Soot Mass ◽  
Temperature Combustion ◽  
Lifted Flames ◽  
Polycyclic Aromatic ◽  
Species Comparisons

A numerical study of in-cylinder soot formation and oxidation processes in n-heptane lifted flames using various soot inception species has been conducted. In a recent study by the authors, it was found that the soot formation and growth regions in lifted flames were not adequately represented by using acetylene alone as the soot inception species. Comparisons with a conceptual model and available experimental data suggested that the location of soot formation regions could be better represented if polycyclic aromatic hydrocarbon (PAH) species were considered as alternatives to acetylene for soot formation processes. Since the local temperatures are much lower under low temperature combustion (LTC) conditions, it is believed that significant soot mass contribution can be attributed to PAH rather than to acetylene. To quantify and validate the above observations, a reduced n-heptane chemistry mechanism has been extended to include PAH species up to four fused aromatic rings (pyrene). The resulting chemistry mechanism was integrated into the multidimensional CFD code KIVA-CHEMKIN for modeling soot formation in lifted flames in a constant volume chamber. The investigation revealed that a simpler model that only considers up to phenanthrene (three fused rings) as the soot inception species has good possibilities for better soot location predictions. The present work highlights and illustrates the various research challenges toward accurate qualitative and quantitative predictions of soot for new low emission combustion strategies for I.C. engines.

Investigation of Low Temperature Combustion Regimes of Biodiesel With n-Butanol Injected in the Intake Manifold of a Compression Ignition Engine

2012 ◽  
Author(s):  
Valentin Soloiu ◽  
Marvin Duggan ◽  
Henry Ochieng ◽  
David Williams ◽  
Gustavo Molina ◽  
...  
Keyword(s):  
Low Temperature ◽  
Heat Release ◽  
Combustion Chamber ◽  
Nox Reduction ◽  
Intake Manifold ◽  
Power Stroke ◽  
Low Temperature Combustion ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Temperature Combustion

In this study, the in-cylinder soot and NOx trade off was investigated in a Compression Engine by implementing Premixed Charge Compression Ignition (PCCI) coupled with Low Temperature Combustion (LTC) for selected regimes of 1–3 bars IMEP. In order to achieve that, an omnivorous (multi-fuel) single cylinder diesel engine was developed by injecting n-butanol in the intake port while being fueled with biodiesel by direct injection in the combustion chamber. By applying this methodology, the in-cylinder pressure decreased by 25% and peak pressure was delayed in the power stroke by about 8 CAD for the cycles in which the n-butanol was injected in the intake manifold at the engine speed of 800 rpm and low engine loads, corresponding to 1–3 bars IMEP. Compared with the baseline taken with ultra-low sulfur diesel no. 2 (USLD#2), the heat release presented a more complex shape. At 1–2 bars IMEP, the premixed charge stage of the combustion totally disappeared and a prolonged diffusion stage was found instead. At 3 bars IMEP, an early low temperature heat release was present that started 6 degrees (1.25 ms) earlier than the diesel reference heat release with a peak at 350 CAD corresponding to 1200 K. Heat losses from radiation of burned gas in the combustion chamber decreased by 10–50% while the soot emissions showed a significant decrease of about 98%, concomitantly with a 98% NOx reduction at 1 IMEP, and 77% at 3 IMEP, by controlling the combustion phases. Gaseous emissions were measured using an AVL SESAM FTIR and showed that there were high increases in CO, HC and NMHC emissions as a result of PCCI/LTC strategy; nevertheless, the technology is still under development. The results of this work indicate that n-butanol can be a very promising fuel alternative including for LTC regimes.

Numerical Study of the Formation of Soot Precursors during Low-Temperature Combustion of a n-Butanol–Diesel Blend

2014 ◽  
Vol 28 (11) ◽  
pp. 7149-7158 ◽  
Author(s):  
Xiaorong Zhou ◽  
Mengtian Song ◽  
Haozhong Huang ◽  
Ruzhi Yang ◽  
Mingxia Wang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Numerical Study ◽  
Low Temperature Combustion ◽  
Soot Precursors ◽  
Temperature Combustion

Modeling Soot Formation Using Reduced Polycyclic Aromatic Hydrocarbon Chemistry in n-Heptane Lifted Flames With Application to Low Temperature Combustion

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Gokul Vishwanathan ◽  
Rolf D. Reitz
Keyword(s):  
Low Temperature ◽  
Polycyclic Aromatic Hydrocarbon ◽  
Aromatic Hydrocarbon ◽  
Internal Combustion Engines ◽  
Soot Formation ◽  
Numerical Study ◽  
Low Temperature Combustion ◽  
Temperature Combustion ◽  
Lifted Flames ◽  
Polycyclic Aromatic

A numerical study of in-cylinder soot formation and oxidation processes in n-heptane lifted flames using various soot inception species has been conducted. In a recent study by the authors, it was found that the soot formation and growth regions in lifted flames were not adequately represented by using acetylene alone as the soot inception species. Comparisons with a conceptual model and available experimental data suggested that the location of soot formation regions could be better represented if polycyclic aromatic hydrocarbon (PAH) species were considered as alternatives to acetylene for soot formation processes. Since the local temperatures are much lower under low temperature combustion conditions, it is believed that significant soot mass contribution can be attributed to PAH rather than to acetylene. To quantify and validate the above observations, a reduced n-heptane chemistry mechanism has been extended to include PAH species up to four fused aromatic rings (pyrene). The resulting chemistry mechanism was integrated into the multidimensional computational fluid dynamics code KIVA-CHEMKIN for modeling soot formation in lifted flames in a constant volume chamber. The investigation revealed that a simpler model that only considers up to phenanthrene (three fused rings) as the soot inception species has good possibilities for better soot location predictions. The present work highlights and illustrates the various research challenges toward accurate qualitative and quantitative predictions of the soot for new low emission combustion strategies for internal combustion engines.

Sign in / Sign up

Export Citation Format

Share Document