Cylinder Pressure Data Acquisition and Heat Release Analysis on a Personal Computer

1986 ◽  
Author(s):  
T. K. Hayes ◽  
L. D. Savage ◽  
S. C. Sorenson
Keyword(s):  
Data Acquisition ◽  
Heat Release ◽  
Personal Computer ◽  
Cylinder Pressure ◽  
Pressure Data ◽  
Release Analysis

Error Propagation in Heat Release Analysis of Pilot Ignited Natural Gas Combustion

2007 ◽  
Author(s):  
J. B. Weathers ◽  
B. T. Marvel ◽  
K. K. Srinivasan ◽  
P. J. Mago ◽  
L. M. Chamra ◽  
...  
Keyword(s):  
Natural Gas ◽  
Uncertainty Analysis ◽  
Heat Release ◽  
Primary Objective ◽  
Cylinder Pressure ◽  
Pressure Data ◽  
Compression Ignition Engine ◽  
Gas Combustion ◽  
Total Uncertainty ◽  
Release Analysis

Uncertainty within measured variables and how such errors propagate throughout a given equation or set of equations can greatly affect the accuracy and understanding of the result for a given experiment. The major motivation (or impetus) for performing a detailed uncertainty analysis before beginning an experiment is to identify variables or parameters that would have the greatest/least impact on the total uncertainty of the result. The scope of this study is to perform a detailed uncertainty analysis on estimates of net heat release in a compression ignition engine. The analysis will examine each term of the net heat release rate equation, which is routinely estimated using a single zone thermodynamic model, and evaluate the respective Uncertainty Magnification Factors (UMF) and Uncertainty Percentage Distribution (UPC). Since the net work output from the engine is directly related to in-cylinder pressure data, it is important to evaluate the uncertainties associated with cylinder pressure measurement. The primary objective of this paper is to analyze the effect of biased and precision uncertainties associated with the measured cylinder pressure data on the rate of heat release (ROHR) of a pilot ignited natural gas engine. Sensitivity analysis of other parameters such as the correct estimation of compression ratio and using appropriate thermodynamic properties of combustion gases are also discussed. The estimates from this analysis are expected to aid the development of a detailed experimental matrix to analyze the nature of energy release and performance of combustion engines.

Assessment of Residual Mass Estimation Methods for Cylinder Pressure Heat Release Analysis of HCCI Engines With Negative Valve Overlap

2011 ◽  
Author(s):  
Elliott A. Ortiz-Soto ◽  
Jiri Vavra ◽  
Aristotelis Babajimopoulos
Keyword(s):  
Heat Release ◽  
State Equation ◽  
Operating Conditions ◽  
Exhaust Valve ◽  
Estimation Methods ◽  
Cylinder Pressure ◽  
Hcci Engines ◽  
Release Analysis ◽  
Negative Valve Overlap ◽  
Valve Overlap

Increased residual levels in Homogeneous Charge Compression Ignition (HCCI) engines employing valve strategies such as recompression or negative valve overlap (NVO) imply that accurate estimation of residual gas fraction (RGF) is critical for cylinder pressure heat release analysis. The objective of the present work was to evaluate three residual estimation methods and assess their suitability under naturally aspirated and boosted HCCI operating conditions: i) the Simple State Equation method employs the Ideal Gas Law at exhaust valve closing (EVC); ii) the Mirsky method assumes isentropic exhaust process; and iii) the Fitzgerald method models in-cylinder temperature from exhaust valve opening (EVO) to EVC by accounting for heat loss during the exhaust process and uses measured exhaust temperature for calibration. Simulations with a calibrated and validated “virtual engine” were performed for representative HCCI operating conditions of engine speed, fuel-air equivalence ratio, NVO and intake pressure (boosting). The State Equation method always overestimated RGF by more than 10%. The Mirsky method was most robust, with average errors between 3–5%. The Fitzgerald method performed consistently better, ranging from no error to 5%, where increased boosting caused the largest discrepancies. A sensitivity study was also performed and determined that the Mirsky method was most robust to possible pressure and temperature measurement errors.

Assessment of Residual Mass Estimation Methods for Cylinder Pressure Heat Release Analysis of HCCI Engines With Negative Valve Overlap

2012 ◽  
Vol 134 (8) ◽  
Author(s):  
Elliott A. Ortiz-Soto ◽  
Jiri Vavra ◽  
Aristotelis Babajimopoulos
Keyword(s):  
Heat Release ◽  
State Equation ◽  
Operating Conditions ◽  
Exhaust Valve ◽  
Estimation Methods ◽  
Cylinder Pressure ◽  
Hcci Engines ◽  
Release Analysis ◽  
Negative Valve Overlap ◽  
Valve Overlap

Increased residual levels in homogeneous charge compression ignition (HCCI) engines employing valve strategies such as recompression or negative valve overlap (NVO) imply that accurate estimation of residual gas fraction (RGF) is critical for cylinder pressure heat release analysis. The objective of the present work was to evaluate three residual estimation methods and assess their suitability under naturally aspirated and boosted HCCI operating conditions: (i) the simple state equation method employs the ideal gas law at exhaust valve closing (EVC); (ii) the Mirsky method assumes isentropic exhaust process; and (iii) the Fitzgerald method models in-cylinder temperature from exhaust valve opening (EVO) to EVC by accounting for heat loss during the exhaust process and uses measured exhaust temperature for calibration. Simulations with a calibrated and validated “virtual engine” were performed for representative HCCI operating conditions of engine speed, fuel-air equivalence ratio, NVO and intake pressure (boosting). The state equation method always overestimated RGF by more than 10%. The Mirsky method was most robust, with average errors between 3–5%. The Fitzgerald method performed consistently better, ranging from no error to 5%, where increased boosting caused the largest discrepancies. A sensitivity study was also performed and determined that the Mirsky method was most robust to possible pressure and temperature measurement errors.

The Estimation of Nitrogen Oxides Reduction Potential Through Enhanced Heat Release Analysis

2016 ◽  
Author(s):  
Tongyang Gao ◽  
Shui Yu ◽  
Kelvin Xie ◽  
Marko Jeftic ◽  
Meiping Wang ◽  
...  
Keyword(s):  
Heat Release ◽  
Reduction Potential ◽  
Nox Reduction ◽  
Close Correlation ◽  
Operating Conditions ◽  
Nox Emission ◽  
Cylinder Pressure ◽  
Release Analysis ◽  
The Impact ◽  
Engine Cycle

An enhanced heat release analysis method is proposed to investigate the NOx emission reduction potential in diesel low temperature combustion and the combustion of premixed ethanol ignited by diesel injections. The heat release analysis from the in-cylinder pressure is a commonly applied diagnostic tool to gain insights in various aspects of combustion, such as start of combustion, ignition delay, combustion phasing, and combustion duration. However, these parameters are more qualitative than quantitative when they are correlated to engine efficiency and emissions. The results are often inconsistent at different engine operating conditions, such as different intake pressure levels, EGR rates and engine loads. In this work, the authors proposed a new parameter named as peak of combustion acceleration, which is the maximum of the first derivative of the heat release rate over an engine cycle. It was observed that the peak of combustion acceleration had a close correlation with the emissions of smoke and NOx at different engine loads and in the combustion of both diesel LTC and premixed ethanol ignited by diesel injections. With the test engine platform, the NOx emission reduced to lower than 50 ppm when the peak of combustion acceleration was less than 25 for diesel LTC and 35 for premixed ethanol ignited by diesel injections. The detailed cylinder pressure sampling and treatment processes were described in this paper. The impact of cycle to cycle variation in the cylinder pressure on the calculation of the peak of combustion acceleration was discussed. The peak of combustion acceleration and the corresponding engine crank angle from each individual engine cycle were calculated and the statistic performance of these parameters was evaluated. The comparison indicated an acceptable consistency between the results from individual engine cycle and from the averaged engine cycles. The proposed peak of combustion acceleration can be potentially integrated in the engine control as an indication of the NOx reduction potential.

Heat Release Analysis of Oxygen-Enriched Diesel Combustion

1993 ◽  
Vol 115 (4) ◽  
pp. 761-768 ◽  
Author(s):  
D. Assanis ◽  
E. Karvounis ◽  
R. Sekar ◽  
W. Marr
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Oxygen Enrichment ◽  
Operating Conditions ◽  
Diesel Combustion ◽  
The Novel ◽  
Pressure Data ◽  
Engine Operation ◽  
Combustion Simulation ◽  
Release Analysis

A heat release correlation for oxygen-enriched diesel combustion is being developed through heat release analysis of cylinder pressure data from a single-cylinder diesel engine operating under various levels of oxygen enrichment. Results show that standard combustion correlations available in the literature do not accurately describe oxygen-enriched diesel combustion. A novel functional form is therefore proposed, which is shown to reproduce measured heat release profiles closely, under different operating conditions and levels of oxygen enrichment. The mathematical complexity of the associated curve-fitting problem is maintained at the same level of difficulty as for standard correlations. When the novel correlation is incorporated into a computer simulation of diesel engine operation with oxygen enrichment, the latter predicts pressure traces in excellent agreement with measured pressure data. This demonstrates the potential of the proposed combustion simulation to guide the application of oxygen-enriched technology successfully to a variety of multicylinder diesel systems.

Preliminary Energy-Efficiency Analysis on Multi-Pulse Injection Schedule in a Diesel Engine

2005 ◽  
Author(s):  
Raj Kumar ◽  
Ming Zheng ◽  
Graham T. Reader
Keyword(s):  
Energy Efficiency ◽  
Diesel Engine ◽  
Heat Release ◽  
Fuel Injection ◽  
Efficiency Analysis ◽  
Simulation Software ◽  
Cylinder Pressure ◽  
Pressure Data ◽  
Exhaust Temperature ◽  
Energy Efficiency Analysis

The multi-pulse fuel injection in a diesel engine is considered an effective way to reduce nitrogen oxides (NOx) emissions by heat-release shaping. In this research a preliminary energy efficiency analysis has been conducted for various split injection rates and schedules using the in-house and the commercial engine simulation software. Theoretical findings have been validated using experimentally obtained cylinder pressure data for various injection timings from a single-cylinder engine. The theoretical analysis on the shape of heat- release has been made to evaluate the energy efficiency of the post injection pulses on the engine exhaust temperature increases. An investigation of the cycle-to-cycle variation has also been performed for the measured cylinder pressure data.

Heat Release Analysis of Engine Pressure Data

1984 ◽  
Author(s):  
J. A. Gatowski ◽  
E. N. Balles ◽  
K. M. Chun ◽  
F. E. Nelson ◽  
J. A. Ekchian ◽  
...  
Keyword(s):  
Heat Release ◽  
Pressure Data ◽  
Release Analysis
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