Proportional–Integral Controller Design for Combustion-Timing Feedback, From n-Heptane to Iso-Octane in Compression–Ignition Engines

2017 ◽  
Vol 140 (5) ◽  
Author(s):  
Gabriel Ingesson ◽  
Lianhao Yin ◽  
Rolf Johansson ◽  
Per Tunestål
Keyword(s):  
Ignition Delay ◽  
Controller Design ◽  
Negative Temperature ◽  
Operating Conditions ◽  
Measurement Noise ◽  
Noise Sensitivity ◽  
Proportional Integral ◽  
Primary Reference ◽  
The Difference ◽  
Primary Reference Fuels

The problem of designing robust and noise-insensitive proportional–integral (PI) controllers for pressure-sensor-based combustion-timing control was studied through simulation. Different primary reference fuels (PRF) and operating conditions were studied. The simulations were done using a physics-based, control-oriented model with an empirical ignition-delay correlation. It was found that the controllable region in between the zero-gain region for early injection timings and the misfire region for late injection timings is strongly PRF dependent. As a result, it was necessary to adjust intake temperature to compensate for the difference in fuel reactivity prior to the controller design. With adjusted intake temperature, PRF-dependent negative-temperature coefficient (NTC) behavior gave different system characteristics for the different fuels. The PI controller design was accomplished by solving the optimization problem of maximizing disturbance rejection and tracking performance subject to constraints on robustness and measurement-noise sensitivity. Optimal controller gains were found to be limited by the high system gain at late combustion timings and high-load conditions; furthermore, the measurement-noise sensitivity was found to be higher at the low-load operating points where the ignition delay is more sensitive to variations in load and intake conditions. The controller-gain restrictions were found to vary for the different PRFs; the optimal gains for higher PRFs were lower due to a higher system gain, whereas the measurement-noise sensitivity was found to be higher for lower PRFs.

Primary & Secondary Reference Fuel Effects as a Function of Compression Ratio in a CFR Diesel Engine

2021 ◽  
Author(s):  
Kevin Burnett ◽  
Ashwani Gupta ◽  
Dianne Luning Prak ◽  
Jim Cowart
Keyword(s):  
Compression Ratio ◽  
Fuel Injection ◽  
Cetane Number ◽  
Operating Conditions ◽  
Combustion Analysis ◽  
Fast Kinetics ◽  
Engine Torque ◽  
Start Of Injection ◽  
Primary Reference ◽  
Primary Reference Fuels

Abstract Primary Reference Fuels (PRFs) and Secondary Reference Fuels (SRFs) in the range of cetane from 30 to 60 were operated in a Waukesha Diesel Cooperative Fuels Research (CFR) engine under operating conditions that emulate the cetane rating test. Due to the large number of test points in this study, the exact ASTM cetane rating protocol was not followed precisely, however these results are representative of cetane characterization testing with very similar equivalence ratio and combustion phasing across a broad range of Ignition Delays (IGDs) that varied as a result of Compression Ratio (CR) changes in the eleven to twenty-two range. Intake air temperature was operated both heated, as in the cetane rating test, as well as at ambient laboratory conditions. Additional research instrumentation was added beyond the standard CFR equipment for advanced combustion analysis. Combustion analysis shows that engine torque and efficiency increase significantly with increases in CR. At longer IGDs representative of the cetane rating test (13 deg IGD), the increase in IGD with reduced cetane number is relatively linear. For all of the fuels tested, IGD steadily monotonically decreases with increased CR significantly by more than a factor of two. Shorter IGDs lead to longer burn durations; fuel effect differences become less important at very high CRs. Associated companion analysis shows that at the time of fuel injection (Start Of Injection – SOI), cylinder pressure roughly doubles over the CRs studied, however, cylinder charge temperature only moderately increases. This effect leads to a doubling in cylinder air charge concentration at the highest CRs showing an important effect on the fast kinetics at high CRs. A common IGD correlation was evaluated showing good agreement except for the high CN fuel. New IGD correlations are also presented.

Experimental investigations to predict optimistic biodiesel(s) and its optimistic operating conditions by varying ignition delay period and fuel spray pressures for lower emissions and better performance

2020 ◽  
Vol 234 (19) ◽  
pp. 3890-3902
Author(s):  
Vishal V Patil ◽  
Ranjit S Patil
Keyword(s):  
Methyl Ester ◽  
Ignition Delay ◽  
Seed Oil ◽  
Delay Period ◽  
Operating Conditions ◽  
Experimental Investigations ◽  
Rubber Seed Oil ◽  
Rubber Seed ◽  
Neem Seed Oil ◽  
Ignition Delay Period

In this study, different characteristics of sustainable renewable biodiesels (those have a high potential of their production worldwide and in India) were compared with the characteristics of neat diesel to determine optimistic biodiesel for the diesel engine at 250 bar spray pressure. Optimistic fuel gives a comparatively lower level of emissions and better performance than other selected fuels in the study. Rubber seed oil methyl ester was investigated as an optimistic fuel among the other selected fuels such as sunflower oil methyl ester, neem seed oil methyl ester, and neat diesel. To enhance the performance characteristics and to further decrease the level of emission characteristics of fuel ROME, further experiments were conducted at higher spray (injection) pressures of 500 bar, 625 bar, and 750 bar with varying ignition delay period via varying its spray timings such as 8°, 13°, 18°, 23°, 28°, and 33° before top dead center. Spray pressure 250 bar at 23° before top dead center was investigated as an optimistic operating condition where fuel rubber seed oil methyl ester gives negligible hydrocarbon emissions (0.019 g/kW h) while its nitrogen oxide (NOX) emissions were about 70% lesser than those observed with neat diesel, respectively.

Laminar burning velocities of primary reference fuels and simple alcohols

Fuel ◽  
2014 ◽  
Vol 115 ◽  
pp. 32-40 ◽  
Author(s):  
L. Sileghem ◽  
V.A. Alekseev ◽  
J. Vancoillie ◽  
E.J.K. Nilsson ◽  
S. Verhelst ◽  
...  
Keyword(s):  
Primary Reference ◽  
Primary Reference Fuels

Production of quicklime from Ashaka limestone through calcination process

2021 ◽  
Vol 1 (2) ◽  
pp. 041-048
Author(s):  
Benson Chinweuba Udeh
Keyword(s):  
Particle Size ◽  
Critical Value ◽  
Operating Conditions ◽  
Quadratic Model ◽  
Particle Sizes ◽  
Calcination Process ◽  
Process Effects ◽  
Effects Of Temperature ◽  
The Difference ◽  
The Relationship

This study is on the production of quicklime from Ashaka limestone through calcination process. Effects of temperature, particle size and time on quicklime yield were determined. The experiment was carried out at temperatures of 800, 900, 1000, 1100 and 1200 0C, particle sizes of 80mm, 90mm, 100mm, 300mm and 425mm and times of 0.5hr, 1hr, 2hrs, 3hrs and 4hrs. Analyses of the results showed that quicklime was successfully produced from Ashaka limestone through the calcination process. Quadratic model adequately described the relationship between quicklime yield and calcination factors of temperature, particle size and time. Recorded model F-value of 134.35 implies that the model is significant. The predicted R² of 0.9597 is in reasonable agreement with the adjusted R² of 0.9844; the difference is less than the critical value of 0.2. Optimum yield of 73.48% was obtained at optima operating conditions; temperature of 1000 0C, particle size of 90 µm and time of 3 hrs.

scholarly journals Primary Reference Fuels (PRFs) as Surrogates for Low Sensitivity Gasoline Fuels

2016 ◽  
Author(s):  
Vijai Shankar Bhavani Shankar ◽  
Muhammad Sajid ◽  
Khalid Al-Qurashi ◽  
Nour Atef ◽  
Issam Alkhesho ◽  
...  
Keyword(s):  
Primary Reference ◽  
Low Sensitivity ◽  
Primary Reference Fuels

scholarly journals Modeling and controller design for an experimental test bench for aircraft actuators

2018 ◽  
Vol 10 (12) ◽  
pp. 168781401881536 ◽  
Author(s):  
Yong Zhou ◽  
Xiaogang Zhou
Keyword(s):  
Experimental Test ◽  
Test Bench ◽  
Controller Design ◽  
Operating Conditions ◽  
Control Performance ◽  
Proportional Integral Derivative ◽  
Hydraulic Actuator ◽  
Aerodynamic Forces ◽  
Ground Testing ◽  
Experimental Test Bench

The reliable and repeatable experimental ground testing of aircraft actuator is an essential phase before flight testing. It is not an easy task to simulate the alternating aerodynamic forces on actuators reasonably and accurately in a laboratory. In this article, an experimental test bench is designed to simulate the aerodynamic forces by a hydraulic actuator, which replicates the operating conditions that the actuator will encounter in service. In order to improve the force control performance, a feed-forward compensator and a fuzzy proportional–integral–derivative controller are designed. Both simulation and experimental results show that the designed method can improve the control performance.

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