scholarly journals A novel method for in-cylinder pressure prediction using the engine instantaneous crankshaft torque

2021 ◽  
pp. 147509022110284
Author(s):  
Konstantinos-Marios Tsitsilonis ◽  
Gerasimos Theotokatos
Keyword(s):  
Internal Combustion Engines ◽  
Maximum Error ◽  
Combustion Engines ◽  
Cylinder Pressure ◽  
Adequate Accuracy ◽  
Marine Engines ◽  
Shaft Power ◽  
Novel Method ◽  
The Mean ◽  
Sigmoid Functions

Current practices of condition assessment in large marine engines are largely based on the measurement of cylinder pressure using external kits, which poses challenges due to sensors synchronisation and durability issues, as well as the inability to perform continuous monitoring. For addressing these challenges, this study aims at developing a novel method to solve the inverse problem of predicting the pressure variations in all engine cylinders, by using the Instantaneous Crankshaft Torque (ICT) measurement for large internal combustion engines. This method is developed by considering the Initial Value Problem (IVP) technique along with the integration of a direct crankshaft dynamics model incorporating the sensitivity parameters and stability criteria calculation based on the Lyapunov Exponent (LE) as well as a state-of-the-art Nonmonotone Self-Adaptive Levenberg-Marquardt (NSALMN) optimisation algorithm. The method is tested for a number of case studies using different combustion models based on the Weibe and sigmoid functions, as well as for healthy, degraded and faulty engine conditions. The derived results demonstrate adequate accuracy exhibiting a maximum error of 0.3% in the prediction of the mean peak in-cylinder pressure. The analysis of the calculated sensitivity parameters resulted in the identification of the parameters that significantly impact the solution, thus providing improved insights for selecting the developed method settings. The developed method renders the continuous and non-intrusive in-cylinder pressures monitoring feasible, by using a permanently installed shaft power metre sensor with higher sample rates.

scholarly journals Capturing Pressure Oscillations in Numerical Simulations of Internal Combustion Engines

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Sreenivasa Rao Gubba ◽  
Ravichandra S. Jupudi ◽  
Shyam Sundar Pasunurthi ◽  
Sameera D. Wijeyakulasuriya ◽  
Roy J. Primus ◽  
...  
Keyword(s):  
Internal Combustion Engines ◽  
Fuel Combustion ◽  
Dual Fuel ◽  
Combustion Engines ◽  
Cylinder Pressure ◽  
Pressure Oscillations ◽  
Numerical Predictions ◽  
Medium Speed ◽  
Dual Fuel Combustion ◽  
The Mean

In an earlier publication (Jupudi et al., 2016, “Application of High Performance Computing for Simulating Cycle-to-Cycle Variation in Dual-Fuel Combustion Engines,” SAE Paper No. 2016-01-0798), the authors compared numerical predictions of the mean cylinder pressure of diesel and dual-fuel combustion, to that of measured pressure data from a medium-speed, large-bore engine. In these earlier comparisons, measured data from a flush-mounted in-cylinder pressure transducer showed notable and repeatable pressure oscillations which were not evident in the mean cylinder pressure predictions from computational fluid dynamics (CFD). In this paper, the authors present a methodology for predicting and reporting the local cylinder pressure consistent with that of a measurement location. Such predictions for large-bore, medium-speed engine operation demonstrate pressure oscillations in accordance with those measured. The temporal occurrences of notable pressure oscillations were during the start of combustion and around the time of maximum cylinder pressure. With appropriate resolutions in time steps and mesh sizes, the local cell static pressure predicted for the transducer location showed oscillations in both diesel and dual-fuel combustion modes which agreed with those observed in the experimental data. Fast Fourier transform (FFT) analysis on both experimental and calculated pressure traces revealed that the CFD predictions successfully captured both the amplitude and frequency range of the oscillations. Resolving propagating pressure waves with the smaller time steps and grid sizes necessary to achieve these results required a significant increase in computer resources.

scholarly journals Influence of cyclic cylinder pressure variability in the numerical transfer path analysis of multi-body engine

2019 ◽  
pp. 1-23
Keyword(s):  
Path Analysis ◽  
Internal Combustion Engines ◽  
Combustion Engines ◽  
Cylinder Pressure ◽  
Cyclic Variability ◽  
Transfer Path ◽  
Engine Vibration ◽  
Stochastic Framework ◽  
Transfer Path Analysis ◽  
Multi Body

Practical mechanical systems often operate with some degree of uncertainty. The uncertainties can result from poorly known or variable parameters, from uncertain inputs or from rapidly changing forcing that can be best described in a stochastic framework. In automotive applications, cylinder pressure variability is one of the uncertain parameters that engineers have to deal with when designing and analyzing internal combustion engines. Multi-body dynamics is a powerful numerical tool largely implemented during the design of new engines. In this paper the influence of cylinder pressure cyclic variability on the results obtained from the multi-body simulation of engine dynamics is investigated. Particular attention is paid to the influence of these uncertainties on the analysis and the assessment of the different engine vibration sources. A numerical transfer path analysis, based on system dynamic sub structuring is used to derive and assess the internal engine vibration sources. In order to investigate the cyclic variability of cylinder pressure, a Monte Carlo approach is adopted. Starting from measured cylinder pressure that exhibits cyclic variability, random Gaussian distribution of the equivalent force applied on the piston is generated. The aim of this paper is to outline a methodology which can be used to derive correlations between cyclic variability and statistical distribution of results. The statistical information derived can be used to advance the knowledge of the multi-body analysis and the assessment of system sources when uncertain inputs are considered.

Engine Control Using Cylinder Pressure: Past, Present, and Future

1993 ◽  
Vol 115 (2B) ◽  
pp. 343-350 ◽  
Author(s):  
J. David Powell
Keyword(s):  
Internal Combustion Engines ◽  
Combustion Engines ◽  
Engine Control ◽  
Pressure Measurements ◽  
Cylinder Pressure ◽  
Automotive Engine ◽  
Spark Timing ◽  
The Cost ◽  
Misfire Detection ◽  
Charge Temperature

Research into the use of cylinder pressure measurements from reciprocating internal combustion engines for real time automotive engine control has been investigated for the last 20 years. The measurement has been investigated for spark timing, fuel-air ratio control, charge temperature measurements, and misfire detection. The cost of the sensors has inhibited widespread use in production vehicles; however, it was introduced in domestic Japanese production for spark control five years ago. Its use for misfire detection is also being actively considered.

scholarly journals The analysis of an unrepeatability of cylinder pressure signal in internal combustion engines

2005 ◽  
Vol 120 (1) ◽  
pp. 31-39
Author(s):  
Zdzisław CHŁOPEK ◽  
Piotr STASIAK
Keyword(s):  
Normal Distribution ◽  
Internal Combustion Engines ◽  
Engine Speed ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Cylinder Pressure ◽  
Static Properties ◽  
Pressure Signal ◽  
Wide Range ◽  
Static Conditions

In this paper an analysis of irrepeatability of cylinder pressure signal in static conditions of engine work was performed. Large irregularity of analysed signal was stated that follows the irregularity of engine speed and pressure value distortions in each quasi–period. A stationarity of cylinder pressure was studied. Resampling data method in the revolution angle domain was suggested. Due to this synchronised averaging, transformed signal was an effective method of eliminating distortions in the basic periodical signal. Static properties of signal deviations (deviations of cylinder pressure from pressure averaged in quasi–periods) were studied. It was stated that the analysed distortions are a wide–range noise and there is no reason to formulate a hypothesis regarding the analysed signal conformity with a normal distribution.

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