Nominated Lecture: Performance and Operation of Spark-Ignited Gas Engines

1966 ◽  
Vol 181 (1) ◽  
pp. 900-922 ◽  
Author(s):  
Malcolm L. Land
Keyword(s):  
Ambient Temperature ◽  
Fuel Consumption ◽  
Temperature Variation ◽  
Constant Pressure ◽  
Engine Performance ◽  
Chemical Processing ◽  
Load Variation ◽  
Extended Discussion ◽  
Stroke Cycle ◽  
Engine Compressors

The author discusses the application of spark-ignited gas engines to such services as gas transmission, gas gathering and chemical processing with integral angle engine-compressors as well as directly coupled units. The author also treats such performance aspects of two-and four-stroke cycle spark-ignited gas engines as: fuel consumption, cyclic dispersion in combustion, accommodation of ambient temperature variation, load variation and altitude. There is an extended discussion of pulse and constant pressure turbocharger characteristics and their influence on engine performance. Important hardware considerations are given, such as design of valves and valve inserts, cylinder heads and pistons.

A numerical investigation of thermal engine encapsulation concept for a passenger vehicle and its effect on fuel consumption

2018 ◽  
Vol 233 (3) ◽  
pp. 557-571 ◽  
Author(s):  
Blago Minovski ◽  
Jelena Andrić ◽  
Lennart Löfdahl ◽  
Peter Gullberg
Keyword(s):  
Ambient Temperature ◽  
Fuel Consumption ◽  
Great Part ◽  
Engine Performance ◽  
Area Coverage ◽  
System Level ◽  
Engine Oil ◽  
Fuel Saving ◽  
Passenger Vehicle ◽  
Cold Starts

Increasingly tough regulations for emission levels and a growing demand for an environmentally clean motor industry impose high requirements in modern automotive development. During recent decades, carmakers have been utilizing various strategies to minimize energy losses in the powertrain to meet legislative and market demands. A great part of research efforts has been focused on improving engine performance during cold starts characterized by increased friction losses. Thermal engine encapsulation is an effective design choice to reduce engine friction in applications with frequent cold starts. In the present work, a coupled 1-D–3-D system-level approach is used to investigate the effects of a novel engine-mounted encapsulation concept featuring air shutters on fuel consumption in a Volvo S80 passenger vehicle. Simulations are performed for sequences of the Worldwide harmonized light vehicles test cycle (WLTC) drive cycle, which include different time intervals of engine inactivity when the car is parked in air of an quiescent ambient temperature. The results show that engine encapsulation with high area coverage (97%) can retain engine oil temperature above 19°C for up to 16 h after engine shutdown at an ambient temperature of 5°C, leading to 2.5% fuel saving during engine warm-up when cold starts occur between 2 and 8 h after key-off. Encapsulations with a lower area coverage (90%) have proven to be less effective, with fuel saving of 1.25% as the temperatures of the oil and engine structures decrease more quickly after key-off compared to the fully enclosed encapsulation.

Application of Box-Behnken Analysis on the Optimisation of Air Intake System for a Naturally Aspirated Engine

2020 ◽  
Vol 17 (2) ◽  
pp. 8029-8042
Author(s):  
N.S. Mustafa ◽  
N.H.A. Ngadiman ◽  
M.A. Abas ◽  
M.Y. Noordin
Keyword(s):  
Fuel Consumption ◽  
Fuel Efficiency ◽  
Engine Performance ◽  
Fuel Price ◽  
Design Expert ◽  
Intake System ◽  
Analysis Technique ◽  
System Components ◽  
Air Intake ◽  
High Influence

Fuel price crisis has caused people to demand a car that is having a low fuel consumption without compromising the engine performance. Designing a naturally aspirated engine which can enhance engine performance and fuel efficiency requires optimisation processes on air intake system components. Hence, this study intends to carry out the optimisation process on the air intake system and airbox geometry. The parameters that have high influence on the design of an airbox geometry was determined by using AVL Boost software which simulated the automobile engine. The optimisation of the parameters was done by using Design Expert which adopted the Box-Behnken analysis technique. The result that was obtained from the study are optimised diameter of inlet/snorkel, volume of airbox, diameter of throttle body and length of intake runner are 81.07 mm, 1.04 L, 44.63 mm and 425 mm, respectively. By using these parameters values, the maximum engine performance and minimum fuel consumption are 93.3732 Nm and 21.3695×10-4 kg/s, respectively. This study has fully accomplished its aim to determine the significant parameters that influenced the performance of airbox and optimised the parameters so that a high engine performance and fuel efficiency can be produced. The success of this study can contribute to a better design of an airbox.

Analysis of temperature and altitude effects on the Global Energy Balance during WLTC

2021 ◽  
pp. 146808742110342
Author(s):  
Francisco Payri ◽  
Jaime Martín ◽  
Francisco José Arnau ◽  
Sushma Artham
Keyword(s):  
Energy Balance ◽  
Ambient Temperature ◽  
Fuel Consumption ◽  
Experimental Measurements ◽  
Compression Ignition ◽  
Oil Viscosity ◽  
Compression Ignition Engine ◽  
Global Energy ◽  
Global Energy Balance ◽  
L Compression

In this work, the Global Energy Balance (GEB) of a 1.6 L compression ignition engine is analyzed during WLTC using a combination of experimental measurements and simulations, by means of a Virtual Engine. The energy split considers all the relevant energy terms at two starting temperatures (20°C and 7°C) and two altitudes (0 and 1000 m). It is shown that reducing ambient temperature from 20°C to −7°C decreases brake efficiency by 1% and increases fuel consumption by 4%, mainly because of the higher friction due to the higher oil viscosity, while the effect of increasing altitude 1000 m decreases brake efficiency by 0.8% and increases fuel consumption by 2.5% in the WLTC mainly due to the change in pumping. In addition, GEB shows that ambient temperature is affecting exhaust enthalpy by 4.5%, heat rejection to coolant by 2%, and heat accumulated in the block by 2.5%, while altitude does not show any remarkable variations other than pumping and break power.

scholarly journals Effect of Methanol/Water Mixed Fuel Compound Injection on Engine Combustion and Emissions

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4491
Author(s):  
Changchun Xu ◽  
Haengmuk Cho
Keyword(s):  
Fuel Consumption ◽  
Ignition Delay ◽  
Fuel Injection ◽  
Fuel Efficiency ◽  
Engine Performance ◽  
Hydroxyl Group ◽  
Combustion Mechanism ◽  
Performance And Emission ◽  
Reduce Emissions ◽  
Concentration Ratios

Due to the recent global increase in fuel prices, to reduce emissions from ground transportation and improve urban air quality, it is necessary to improve fuel efficiency and reduce emissions. Water, methanol, and a mixture of the two were added at the pre-intercooler position to keep the same charge and cooling of the original rich mixture, reduce BSFC and increase ITE, and promote combustion. The methanol/water mixing volume ratios of different fuel injection strategies were compared to find the best balance between fuel consumption, performance, and emission trends. By simulating the combustion mechanism of methanol, water, and diesel mixed through the Chemkin system, the ignition delay, temperature change, and the generation rate of the hydroxyl group (−OH) in the reaction process were analyzed. Furthermore, the performance and emission of the engine were analyzed in combination with the actual experiment process. This paper studied the application of different concentration ratios of the water–methanol–diesel mixture in engines. Five concentration ratios of water–methanol blending were injected into the engine at different injection ratios at the pre-intercooler position, such as 100% methanol, 90% methanol/10% water, 60% methanol/40% water, 30% methanol/70% water, 100% water was used. With different volume ratios of premixes, the combustion rate and combustion efficiency were affected by droplet extinguishment, flashing, or explosion, resulting in changes in combustion temperature and affecting engine performance and emissions. In this article, the injection carryout at the pre-intercooler position of the intake port indicated thermal efficiency increase and a brake specific fuel consumption rate decrease with the increase of water–methanol concentration, and reduce CO, UHC, and nitrogen oxide emissions. In particular, when 60% methanol and 40% water were added, it was found that the ignition delay was the shortest and the cylinder pressure was the largest, but the heat release rate was indeed the lowest.

Two-Stroke Marine Diesel Engine Variable Injection Timing System Performance Evaluation and Optimum Setting for Minimum Fuel Consumption at Acceptable NOx Levels

2014 ◽  
Author(s):  
Dimitrios T. Hountalas ◽  
Spiridon Raptotasios ◽  
Antonis Antonopoulos ◽  
Stavros Daniolos ◽  
Iosif Dolaptzis ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Engine Performance ◽  
Operating Conditions ◽  
Specific Fuel Consumption ◽  
Injection Timing ◽  
Nox Emissions ◽  
Pressure Measurements ◽  
Cylinder Pressure ◽  
Start Of Injection

Currently the most promising solution for marine propulsion is the two-stroke low-speed diesel engine. Start of Injection (SOI) is of significant importance for these engines due to its effect on firing pressure and specific fuel consumption. Therefore these engines are usually equipped with Variable Injection Timing (VIT) systems for variation of SOI with load. Proper operation of these systems is essential for both safe engine operation and performance since they are also used to control peak firing pressure. However, it is rather difficult to evaluate the operation of VIT system and determine the required rack settings for a specific SOI angle without using experimental techniques, which are extremely expensive and time consuming. For this reason in the present work it is examined the use of on-board monitoring and diagnosis techniques to overcome this difficulty. The application is conducted on a commercial vessel equipped with a two-stroke engine from which cylinder pressure measurements were acquired. From the processing of measurements acquired at various operating conditions it is determined the relation between VIT rack position and start of injection angle. This is used to evaluate the VIT system condition and determine the required settings to achieve the desired SOI angle. After VIT system tuning, new measurements were acquired from the processing of which results were derived for various operating parameters, i.e. brake power, specific fuel consumption, heat release rate, start of combustion etc. From the comparative evaluation of results before and after VIT adjustment it is revealed an improvement of specific fuel consumption while firing pressure remains within limits. It is thus revealed that the proposed method has the potential to overcome the disadvantages of purely experimental trial and error methods and that its use can result to fuel saving with minimum effort and time. To evaluate the corresponding effect on NOx emissions, as required by Marpol Annex-VI regulation a theoretical investigation is conducted using a multi-zone combustion model. Shop-test and NOx-file data are used to evaluate its ability to predict engine performance and NOx emissions before conducting the investigation. Moreover, the results derived from the on-board cylinder pressure measurements, after VIT system tuning, are used to evaluate the model’s ability to predict the effect of SOI variation on engine performance. Then the simulation model is applied to estimate the impact of SOI advance on NOx emissions. As revealed NOx emissions remain within limits despite the SOI variation (increase).

Characteristics of Water-in-Diesel Emulsions in a Single Cylinder Compression Ignition Engine

2014 ◽  
Author(s):  
Teja Gonguntla ◽  
Robert Raine ◽  
Leigh Ramsey ◽  
Thomas Houlihan
Keyword(s):  
Fuel Consumption ◽  
Direct Injection ◽  
Engine Performance ◽  
Operating Conditions ◽  
Specific Fuel Consumption ◽  
Brake Specific Fuel Consumption ◽  
Compression Ignition Engine ◽  
Oil Emulsion ◽  
Single Cylinder ◽  
Performance And Emission

The objective of this project was to develop both engine performance and emission profiles for two test fuels — a 6% water-in-diesel oil emulsion (DOE-6) fuel and a neat diesel (D100) fuel. The testing was performed on a single cylinder, direct-injection, water-cooled diesel engine coupled to an eddy current dynamometer. Output parameters of the engine were used to calculate Brake Specific Fuel Consumption (BSFC) and Engine Efficiency (η) for each test fuel. DOE-6 fuels generated a 24% reduction in NOX and a 42% reduction in Carbon Monoxide emissions over the tested operating conditions. DOE-6 fuels presented higher ignition delays — between 1°-4°, yielded 1%–12% lower peak cylinder pressures and produced up to 5.5% lower exhaust temperatures. Brake Specific Fuel consumption increased by 6.6% for the DOE-6 fuels as compared to the D100 fuels. This project is the first research done by a New Zealand academic institution on water-in-diesel emulsion fuels.

Optimization of Turbofan Propulsion Cycle Using a Genetic Algorithm

2010 ◽  
Author(s):  
Adel Ghenaiet
Keyword(s):  
Genetic Algorithm ◽  
Fuel Consumption ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Optimization Procedure ◽  
Specific Fuel Consumption ◽  
High Mass ◽  
Design Parameters ◽  
Inlet Temperature ◽  
Simplifying Assumptions

This paper presents an evolutionary approach as the optimization framework to design for the optimal performance of a high-bypass unmixed turbofan to match with the power requirements of a commercial aircraft. The parametric analysis had the objective to highlight the effects of the principal design parameters on the propulsive performance in terms of specific fuel consumption and specific thrust. The design optimization procedure based on the genetic algorithm PIKAIA coupled to the developed engine performance analyzer (on-design and off-design) aimed at finding the propulsion cycle parameters minimizing the specific fuel consumption, while meeting the required thrusts in cruise and takeoff and the restrictions of temperatures limits, engine size and weight as well as pollutants emissions. This methodology does not use engine components’ maps and operates on simplifying assumptions which are satisfying the conceptual or early design stages. The predefined requirements and design constraints have resulted in an engine with high mass flow rate, bypass ratio and overall pressure ratio and a moderate turbine inlet temperature. In general, the optimized engine is fairly comparable with available engines of equivalent power range.

The WLTC vs NEDC: A Case Study on the Impacts of Driving Cycle on Engine Performance and Fuel Consumption

2021 ◽  
Vol 18 (3) ◽  
pp. 9071-9081
Author(s):  
Jakub Lasocki
Keyword(s):  
Fuel Consumption ◽  
Combustion Engine ◽  
Engine Performance ◽  
Driving Cycle ◽  
Performance Characteristics ◽  
Pollutant Emission ◽  
Strong Impact ◽  
Light Duty ◽  
Light Duty Vehicles

The World-wide harmonised Light-duty Test Cycle (WLTC) was developed internationally for the determination of pollutant emission and fuel consumption from combustion engines of light-duty vehicles. It replaced the New European Driving Cycle (NEDC) used in the European Union (EU) for type-approval testing purposes. This paper presents an extensive comparison of the WLTC and NEDC. The main specifications of both driving cycles are provided, and their advantages and limitations are analysed. The WLTC, compared to the NEDC, is more dynamic, covers a broader spectrum of engine working states and is more realistic in simulating typical real-world driving conditions. The expected impact of the WLTC on vehicle engine performance characteristics is discussed. It is further illustrated by a case study on two light-duty vehicles tested in the WLTC and NEDC. Findings from the investigation demonstrated that the driving cycle has a strong impact on the performance characteristics of the vehicle combustion engine. For the vehicles tested, the average engine speed, engine torque and fuel flow rate measured over the WLTC are higher than those measured over the NEDC. The opposite trend is observed in terms of fuel economy (expressed in l/100 km); the first vehicle achieved a 9% reduction, while the second – a 3% increase when switching from NEDC to WLTC. Several factors potentially contributing to this discrepancy have been pointed out. The implementation of the WLTC in the EU will force vehicle manufacturers to optimise engine control strategy according to the operating range of the new driving cycle.

Adaptive calibration of Diesel engine injection for minimising fuel consumption with constrained NOx emissions in actual driving missions

2020 ◽  
pp. 146808742091880
Author(s):  
José Manuel Luján ◽  
Benjamín Pla ◽  
Pau Bares ◽  
Varun Pandey
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Time Window ◽  
Transition Probability ◽  
Estimation Method ◽  
Engine Performance ◽  
Driving Cycle ◽  
Vehicle Speed ◽  
Adaptive Calibration ◽  
Emission Limits

This article proposes a method for fuel minimisation of a Diesel engine with constrained [Formula: see text] emission in actual driving mission. Specifically, the methodology involves three developments: The first is a driving cycle prediction tool which is based on the space-variant transition probability matrix obtained from an actual vehicle speed dataset. Then, a vehicle and an engine model is developed to predict the engine performance depending on the calibration for the estimated driving cycle. Finally, a controller is proposed which adapts the start-of-injection calibration map to fulfil the [Formula: see text] emission constraint while minimising the fuel consumption. The calibration is adapted during a predefined time window based on the predicted engine performance on the estimated cycle and the difference between the actual and the constraint on engine [Formula: see text] emissions. The method assessment was done experimentally in the engine test set-up. The engine performace using the method is compared with the state-of-the-art static calibration method for different [Formula: see text] emission limits on real driving cycles. The online implementation of the method shows that the fuel consumption can be reduced by 3%–4% while staying within the emission limits, indicating that the estimation method is able to capture the main driving cycle characterstics.

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