Comparison Between Measured Radiance and a Radiation Model in a Spark-Ignition Engine

1990 ◽  
Vol 112 (3) ◽  
pp. 331-334 ◽  
Author(s):  
J. Yang ◽  
S. L. Plee ◽  
D. J. Remboski ◽  
J. K. Martin
Keyword(s):  
Heat Release ◽  
Release Rate ◽  
Maximum Rate ◽  
Spark Ignition ◽  
Rate Of Change ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Maximum Heat ◽  
Radiant Intensity ◽  
Maximum Heat Release

Measurements of the radiant emission in the near infrared have been obtained in a spark-ignition engine over a wide range of operating conditions. The system includes an in-cylinder optical sensor and associated detector. Prior work has shown correlations between the measured radiance and pressure quantities such as maximum cylinder pressure, crank angle of maximum pressure, and Indicated Mean Effective Pressure. Here are presented comparisons between the radiant intensity and a simplified model of the radiation emission, which demonstrate that the measured intensity is a function of the mass-burn fraction, mean burned-gas temperature, and the exposed combustion-chamber surface area. Further simplification leads to the conclusion that the time of the maximum rate of change of radiant intensity is the same as for the maximum heat-release rate, leading to the possibility of feedback control of spark timing. In addition, the magnitudes of the maximum rate of change of radiant emission and maximum heat-release rate have a linear relationship over a range of different operating conditions.

Numerical Investigation of Fuel Property Effects on Mixed-Mode Combustion in a Spark-Ignition Engine

2019 ◽  
Author(s):  
Chao Xu ◽  
Pinaki Pal ◽  
Xiao Ren ◽  
Sibendu Som ◽  
Magnus Sjöberg ◽  
...  
Keyword(s):  
Heat Release ◽  
Flame Propagation ◽  
Heat Release Rate ◽  
Release Rate ◽  
Octane Number ◽  
Mixed Mode ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Chemical Effect ◽  
Auto Ignition

Abstract In the present study, mixed-mode combustion of an E30 fuel in a direct-injection spark-ignition engine is numerically investigated at a fuel-lean operating condition using multidimensional computational fluid dynamics (CFD). A fuel surrogate matching Research Octane Number (RON) and Motor Octane Number (MON) of E30 is first developed using neural network based non-linear regression model. To enable efficient 3D engine simulations, a 164-species skeletal reaction mechanism incorporating NOx chemistry is reduced from a detailed chemical kinetic model. A hybrid approach that incorporates the G-equation model for tracking turbulent flame front, and the multi-zone well-stirred reactor model for predicting auto-ignition in the end gas, is employed to account for turbulent combustion interactions in the engine cylinder. Predicted in-cylinder pressure and heat release rate traces agree well with experimental measurements. The proposed modelling approach also captures moderated cyclic variability. Two different types of combustion cycles, corresponding to purely deflagrative and mixed-mode combustion, are observed. In contrast to the purely deflagrative cycles, mixed-mode combustion cycles feature early flame propagation followed by end-gas auto-ignition, leading to two distinctive peaks in heat release rate traces. The positive correlation between mixed-mode combustion cycles and early flame propagation is well captured by simulations. With the validated numerical setup, effects of NOx chemistry on mixed-mode combustion predictions are investigated. NOx chemistry is found to promote auto-ignition through residual gas recirculation, while the deflagrative flame propagation phase remains largely unaffected. Local sensitivity analysis is then performed to understand effects of physical and chemical properties of the fuel, i.e., heat of evaporation (HoV) and laminar flame speed (SL). An increased HoV tends to suppress end-gas auto-ignition due to increased vaporization cooling, while the impact of HoV on flame propagation is insignificant. In contrast, an increased SL is found to significantly promote both flame propagation and auto-ignition. The promoting effect of SL on auto-ignition is not a direct chemical effect; it is rather caused by an advancement of the combustion phasing, which increases compression heating of the end gas.

scholarly journals Estimation of Magnitude and Heat Release Rate of Fires Occurring in Historic Buildings-Taking Churches as an Example

2021 ◽  
Vol 13 (16) ◽  
pp. 9193
Author(s):  
Wen-Yao Chang ◽  
Chieh-Hsin Tang ◽  
Ching-Yuan Lin
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Water Mist ◽  
Smoke Detector ◽  
Fire Dynamics ◽  
Historical Building ◽  
Maximum Heat ◽  
Improvement Measures ◽  
Maximum Heat Release

Historical buildings often fail to meet today’s building and fire protection regulations due to their structure and space restrictions. For this reason, if such buildings encounter fire, serious damage will be resulted. The fire of the Notre-Dame Cathedral in Paris (Notre-Dame de Paris) in April 2019 highlights the seriousness of this problem. In this study, the historical building of “Tamsui Church” was selected as an example. The Fire Dynamics Simulator (FDS) was adopted to analyze the scale of damage and possible hazards when the wooden seats in the church are on fire, and improvement measures were proposed to ensure that such buildings can be used under safer conditions. It was found that the existing seat arrangement will cause the spreading of fire, and the maximum heat release rate is 2609.88 kW. The wooden roof frame above the fire source will also start to burn at 402.88 s (6.6 min) after the fire, which will lead to a full-scale fire. To maintain the safety of the historical building, it is necessary to add active firefighting equipment (smoke detector and water mist system).

scholarly journals A Numerical Study on the Effect of Volume Change in a Closed Compartment on Maximum Heat Release Rate

2017 ◽  
Vol 31 (5) ◽  
pp. 19-27
Author(s):  
Hong-Seok Yun ◽  
◽  
Dong-Gun Nam ◽  
Cheol-Hong Hwang ◽  
◽  
...  
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Volume Change ◽  
Release Rate ◽  
Numerical Study ◽  
Maximum Heat ◽  
Maximum Heat Release

scholarly journals Differences between Free and Compartment Burning of Furniture Part 2 Maximum Heat Release Rate and Fire Growth Rate

2007 ◽  
Vol 26 (4) ◽  
pp. 523-527
Author(s):  
Akihide Jo ◽  
Takayuki Orito ◽  
Norichika Kakae ◽  
Yoshifumi Ohmiya ◽  
Kaoru Wakatsuki
Keyword(s):  
Growth Rate ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Fire Growth ◽  
Maximum Heat ◽  
Maximum Heat Release

Burning Behavior of Upholstered Furniture Mockups

1984 ◽  
Vol 2 (3) ◽  
pp. 205-235 ◽  
Author(s):  
John F. Krasny ◽  
Vytenis Babrauskas
Keyword(s):  
Heat Release ◽  
Combustion Product ◽  
Heat Release Rate ◽  
Flame Spread ◽  
Release Rate ◽  
Product Concentration ◽  
Light Olefin ◽  
Maximum Heat ◽  
Maximum Heat Release ◽  
Furniture Calorimeter

Furniture mockups consisting of various arrangements of full-size cushions were tested in the NBS furniture calorimeter. Measurements included heat release, combustion product concentrations, and flame spread characteristics. Major variations in burning were observed: neoprene mockups only smoldered, flame retardant treated polyurethane mockups burned more slowly than un treated mockups but eventually reached similar maximum heat release rates. Fabrics were ranked, in terms of maximum heat release rate and several other measured characteristics, from low to high: heavy cotton fabric; light cotton and heavy olefin, and light olefin. Flame spread rate measured on the mockups cor related with the time to reach a 100 kW heat release rate. Heat release rate and combustion product concentration generally increased with increasing number of cushions per mockup. Thinner cushions burned more rapidly than thicker ones.

scholarly journals Analysis of the Maximum Heat Release Rate in Accordance with the Test Method of the Flame Retardant Performance for Pipe Insulation

2020 ◽  
Vol 34 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Woo Jun You ◽  
Jung Wook Park ◽  
Yeon Je Sin ◽  
Hyeong Gyu Park ◽  
Ohk Kun Lim
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Test Method ◽  
Fundamental Study ◽  
Maximum Heat ◽  
Test Standards ◽  
Maximum Heat Release ◽  
Flame Retardation ◽  
Pipe Insulation

In this study, the heat release rate of pipe insulation is analyzed by considering the installation status in accordance with the standards ISO 20632 and NFPA 274. The flame retardation rate was evaluated for six types of test samples: polyethylene foam covered with beaten silver (PE(S)), PE foam tapped (PE(N)), elastomeric closed cell thermal insulation (rubber), Japanese PE foam (PE(J)), Japanese polyurethane foam (PU(J)), and Japanese styro form (ST(J)) by EN 13501-1 and fire growth curve. The results show that PU(J), PE(J), and PE(N) were Class E and ultra-fast, NFPA 274 test standards for Class D and Fast, and PE(S) by ISO 20632 were Class C and Slow, and Rubber and ST(J) were Classes and Low. However, the changes in the time-averaged maximum heat release rate for each test standard (ISO 20632 and NFPA 274) to evaluate the flame retardation rate differed among identical materials. This means that the fundamental study is necessary to analyze the more accurate reasons.

scholarly journals Modeling of the Heat Release Rate Curve of Rigid Plastic Combustibles Based on their Geometrical Properties and Constituent Materials

2021 ◽  
Vol 35 (4) ◽  
pp. 1-7
Author(s):  
Jaeyoung Lee
Keyword(s):  
Growth Rate ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Rate Curve ◽  
Fire Growth ◽  
Rigid Plastic ◽  
Maximum Heat ◽  
Geometrical Properties ◽  
Maximum Heat Release

In this study, we conducted the modeling and generalization of the heat release rate of rigid plastic combustibles with respect to their geometrical properties. The modeling and generalization was carried out using the model proposed by Natori, which is based on the combustion behavior of wooden furniture. Previous studies that have reported the combustion of printers were used for the modeling of the heat release rate of rigid plastic combustibles. The reported heat release rate measurements of the printers were examined to determine their applicability to Natori's model. After their applicability was confirmed, to generalize the heat release rate curve, heat release rate parameters of the combustibles were analyzed with respect to their geometrical properties and constituent materials. The combustibles were classified into two groups based on their geometrical properties, and the fire growth rate, maximum heat release rate, and decay rate represented the heat release rate parameters. Furthermore, the parameters were analyzed as a function of the apparent density of the combustibles. The fire growth rate and maximum heat release rate exhibited a relatively evident correlation with the apparent density, which indicated that an accurate estimation of the heat release rate curve can be obtained from the external dimensions and weight of the combustibles.

Sign in / Sign up

Export Citation Format

Share Document