Effect of Nitromethane Addition on the Performance of Two-Stroke Spark Ignition Unmanned Aerial Vehicles Piston Engine

2020 ◽  
Vol 142 (6) ◽  
Author(s):  
S. Raviteja ◽  
P. A. Ramakrishna ◽  
A. Ramesh
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Engine Performance ◽  
Spark Ignition ◽  
High Heat ◽  
Specific Power ◽  
Fuel Additive ◽  
Engine Torque ◽  
Aerial Vehicles ◽  
Spark Timing ◽  
Pressure Trace

Abstract Nitromethane has a stoichiometric air–fuel ratio of 1.7, which is 8.5 times lower than gasoline. For the same amount of air being drawn by the engine, more amount of nitromethane blends and hence more energy can be added. Methanol was used as a medium to mix nitromethane and gasoline, which are normally immiscible. Engine performance tests were carried out to study the effect of nitromethane addition to the methanol-gasoline blend. A large rise in engine torque and brake thermal efficiency (BTE) was obtained during the investigation. However, the brake specific fuel consumption (BSFC) also increased for the nitromethane blends. The engine parameters like spark timing, equivalence ratio, and compression ratio were optimized to further increase the engine power and also bring down the BSFC. A net torque improvement of 42%, BTE improvement of 35%, and BSFC rise of 9% were obtained by adding nitromethane and methanol in small fractions to gasoline. Combustion analysis was carried out using the cylinder pressure trace. High heat release rate and shorter combustion duration with nitromethane addition were observed. Emission measurements showed decrease in HC and CO emissions with nitromethane addition. However, a drastic rise in NO emissions was observed. Hence, it can be concluded that the specific power of small two-stroke spark ignition (SI) engines can be enhanced using nitromethane as a fuel additive to increase the payload of the unmanned aerial vehicles.

Study on the efficiency of a spark-ignition variable displacement and compression ratio engine

2020 ◽  
pp. 146808742094434
Author(s):  
Caio H Rufino ◽  
Janito V Ferreira
Keyword(s):  
Compression Ratio ◽  
Fuel Injection ◽  
Engine Performance ◽  
Spark Ignition ◽  
Stroke Length ◽  
Spark Timing ◽  
Partial Load ◽  
Simulation Based ◽  
Variable Displacement ◽  
Promising Solution

A variable stroke engine was proposed as a promising solution for improving the efficiency of flex-fuel engines by adjusting the compression ratio; this prevents knock onset for fuels with different octane numbers. Similarly, the displacement was adjusted by varying stroke length with the objective of mitigating cylinder pumping losses. This article compares the efficiency of a spark-ignition, port-fuel injection engine, with variable displacements and compression ratios; a conventional engine with a fixed compression ratio; and an engine with variable compression ratios. A simulation-based calibration was performed for each engine, using the results from a phenomenological model to predict the engine performance. The calibration maps were obtained by maximising efficiency through determining the optimal combination of available engine parameters such as spark timing, compression ratio, displacement, and throttle actuation. A comparison of the efficiencies of the different types of engines showed an improvement of approximately 15% for the engine under partial load conditions and with variable displacement and compression ratio, compared to a conventional engine.

Particulate Matter Emission Comparison of Spark Ignition Direct Injection (SIDI) and Port Fuel Injection (PFI) Operation of a Boosted Gasoline Engine

2013 ◽  
Author(s):  
Jianye Su ◽  
Weiyang Lin ◽  
Jeff Sterniak ◽  
Min Xu ◽  
Stanislav V. Bohac
Keyword(s):  
Particulate Matter ◽  
Gasoline Engine ◽  
Fuel Injection ◽  
Direct Injection ◽  
Spark Ignition ◽  
Specific Power ◽  
Injection Timing ◽  
Gasoline Engines ◽  
Port Fuel Injection ◽  
Spark Timing

Spark ignition direct injection (SIDI) gasoline engines, especially in downsized boosted engine platforms, are increasing their market share relative to port fuel injection (PFI) engines in U.S., European and Chinese vehicles due to better fuel economy by enabling higher compression ratios and higher specific power output. However, particulate matter (PM) emissions from engines are becoming a concern due to adverse human health and environment effects, and more stringent emission standards. To conduct a PM number and size comparison between SIDI and PFI systems, a 2.0 L boosted gasoline engine has been equipped and tested with both systems at different loads, air fuel ratios, spark timings, fuel pressures and injection timings for SIDI operation and loads, air fuel ratios and spark timings for PFI operation. Regardless of load, air fuel ratio, spark timing, fuel pressure, and injection timing, particle size distribution from SIDI and PFI is shown to be bimodal, exhibiting nucleation and accumulation mode particles. SIDI produces particle numbers that are an order of magnitude greater than PFI. Particle number can be reduced by retarding spark timing and operating the engine lean, both for SIDI and PFI operation. Increasing fuel injection pressure and optimizing injection timing with SIDI also reduces PM emissions. This study provides insight into the differences in PM emissions from boosted SIDI and PFI engines and an evaluation of PM reduction potential by varying engine operating parameters in boosted SIDI and PFI gasoline engines.

An Investigation of the Effect of 2T Oil Blend on Spark Ignition Engine Performance

2014 ◽  
Vol 663 ◽  
pp. 289-293
Author(s):  
M. Nurhidayat Zahelem ◽  
A. Siti Rohana ◽  
N. Haniza B. Jemily ◽  
M. Amzari Aris ◽  
Shukri Zain ◽  
...  
Keyword(s):  
Engine Performance ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Si Engine ◽  
Brake Thermal Efficiency ◽  
Blend Ratio ◽  
Engine Torque ◽  
Synthetic Oil ◽  
Brake Mean Effective Pressure ◽  
Oil Blend

This paper presents the results of an investigation on the effect of 2T oil blend on the performance of Spark Ignition (SI) engine. Three different types of 2T-oils; mineral oil, semi-synthetic oil and fully synthetic oil were tested according to blend ratio before the mixing process with fuel in the carburetor. In the experiment, a two-stroke single-cylinder engine was coupled to a 20 kW generator dynamometer to measure engine performance parameters; engine torque, engine power (B.P), brake thermal efficiency (BTE), brake specific fuel consumption (BSFC) and brake mean effective pressure (BMEP) at various engine speeds with maximum engine load. The results show correlation between engine performances and 2T-oil blended as a function of type of 2T-oils used.

Particulate Matter Emission Comparison of Spark Ignition Direct Injection (SIDI) and Port Fuel Injection (PFI) Operation of a Boosted Gasoline Engine

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
Jianye Su ◽  
Weiyang Lin ◽  
Jeff Sterniak ◽  
Min Xu ◽  
Stanislav V. Bohac
Keyword(s):  
Particulate Matter ◽  
Gasoline Engine ◽  
Fuel Injection ◽  
Direct Injection ◽  
Spark Ignition ◽  
Specific Power ◽  
Injection Timing ◽  
Gasoline Engines ◽  
Port Fuel Injection ◽  
Spark Timing

Spark ignition direct injection (SIDI) gasoline engines, especially in downsized boosted engine platforms, are increasing their market share relative to port fuel injection (PFI) engines in U.S., European and Chinese vehicles due to better fuel economy by enabling higher compression ratios and higher specific power output. However, particulate matter (PM) emissions from engines are becoming a concern due to adverse human health and environment effects, and more stringent emission standards. To conduct a PM number and size comparison between SIDI and PFI systems, a 2.0 L boosted gasoline engine has been equipped and tested with both systems at different loads, air fuel ratios, spark timings, fuel pressures and injection timings for SIDI operation and loads, air fuel ratios and spark timings for PFI operation. Regardless of load, air fuel ratio, spark timing, fuel pressure, and injection timing, particle size distribution from SIDI and PFI is shown to be bimodal, exhibiting nucleation and accumulation mode particles. SIDI produces particle numbers that are an order of magnitude greater than PFI. Particle number can be reduced by retarding spark timing and operating the engine lean, both for SIDI and PFI operation. Increasing fuel injection pressure and optimizing injection timing with SIDI also reduces PM emissions. This study provides insight into the differences in PM emissions from boosted SIDI and PFI engines and an evaluation of PM reduction potential by varying engine operating parameters in boosted SIDI and PFI gasoline engines.

AN OVERVIEW OF SPARK IGNITION ENGINE OPERATING ON LOWER-HIGHER MOLECULAR MASS ALCOHOL BLENDED GASOLINE FUELS

2015 ◽  
Vol 76 (5) ◽  
Author(s):  
Hazim Sharudin ◽  
Nik Rosli Abdullah ◽  
A. M. I. Mamat ◽  
Obed M. Ali ◽  
Rizalman Mamat
Keyword(s):  
Molecular Weight ◽  
Chemical Properties ◽  
Engine Performance ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Fuel Properties ◽  
Fuel Additive ◽  
Performance And Emissions ◽  
The Difference ◽  
Physical And Chemical

This paper reviews the utilization of lower and higher molecular weight alcohols as fuel for spark ignition engine. As an alternative fuel for spark ignition engine, alcohol is widely accepted as comparable to gasolin. It is due to its ability that can be produced from biological matter through the current available and new processes. Moreover, alcohol is also considered as fuel additive due to its physical and chemical properties compatible with the requirements of modern engines. The objective of this paper is to provide an overview of these fuels by highlighting on the fuel properties and spark ignition engine responses. The first part of this review explains the important of alcohol fuel properties related to the engine performance and emissions, and the difference of these properties for each type of alcohol. The second part discusses recent advancements in research involving lower and higher molecular weight alcohols mainly responses from spark ignition engine.

scholarly journals Evaluation of the impact of the hydration degree of bioethanol on the operation parameters of the spark-ignition engine

2017 ◽  
Vol 169 (2) ◽  
pp. 71-75
Author(s):  
Marlena OWCZUK ◽  
Anna MATUSZEWSKA ◽  
Małgorzata ODZIEMKOWSKA ◽  
Mateusz BEDNARSKI ◽  
Marcin WOJS ◽  
...  
Keyword(s):  
Water Content ◽  
Engine Performance ◽  
Spark Ignition ◽  
Alcohol Concentration ◽  
Spark Ignition Engine ◽  
Cylinder Pressure ◽  
Engine Torque ◽  
Measurement Results ◽  
High Engine Speed ◽  
The Impact

The article presents an overview of methods for the production of bioethanol and the possibility of its use to power internalcombustion engines. The effects of supplying spark-ignition engine with bioethanol having various degrees of hydration were examined experimentally on the engine dynamometer. The measurement results were referred to the anhydrous bioethanol, which is used widely as petrol biocomponent and compared in terms of the course of the pressure in the combustion chamber of the engine as well as engine performance parameters – torque and power. It was found that with the decrease in alcohol concentration, the performance of the sparkignition engine deteriorated. The reduction of in-cylinder pressure was proportional to the increase in the water content in the fuel. No significant changes in the general shape of in-cylinder pressure curves were observed. Engine torque and power decreased with an increase in the water content in the fuel, especially at high engine speed. It has been stated that supplying the engine with bioethanol containing up to 6% (v/v) of water does not result in significant losses in engine performance.

Performance of Combustion and Emissions Characteristics of Ethanol Dual Injection Spark Ignition Engine

2021 ◽  
Vol 18 (3) ◽  
pp. 9082-9093
Author(s):  
NIZAR F.O. AL-MUHSEN ◽  
Guang Hong ◽  
Firas Basim Ismail
Keyword(s):  
New Technology ◽  
Direct Injection ◽  
Engine Performance ◽  
Volume Ratio ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Nitric Oxides ◽  
Ethanol Fuel ◽  
Spark Timing ◽  
Dual Injection

Ethanol dual injection (DualEI) is a new technology to maximise the benefits of ethanol fuel to the spark-ignition engine. In this study, the combustion and emissions characteristics in a DualEI spark-ignition engine with a variation of the direct injection (DI) ratio and engine speed were experimentally investigated. The volume ratio of DI was varied from 0% (DI0%) to 100% (DI100%), and two engine speeds of 3500 and 4000 RPM were tested. The spark timing for maximum brake torque (MBT) was first determined, and then the results of the effect of DI ratio on the engine performance at the MBT conditions were discussed and analysed. The results showed that the MBT timing for the DI and spark timings were 330 and 30 CAD bTDC, respectively. At the MBT timing, the indicated mean effective pressure slightly increased from 0.47 to 0.50 MPa when the DI ratio increased from DI0% to DI100%. However, the maximum combustion pressure significantly decreased by 8.32%, and volumetric efficiency increased by 4.04%. This was attributed to the reduced combustion temperature due to the cooling effect of ethanol fuel enhanced by the DI strategy. The indicated specific carbon monoxide and hydrocarbons significantly increased due to poor mixture quality caused by fuel impingement associated with the overcooling effect. However, the indicated specific nitric oxides significantly decreased due to the temperature reduction inside the combustion chamber. Results showed the potential of DualEI to increase the compression ratio and consequently increase the engine thermal efficiency without the risk of engine knock.

Increasing the Lubricity of JP-8 to Fuel Two-stroke Spark Ignition Engines for Midsized Unmanned Aerial Vehicles

2011 ◽  
Author(s):  
James Howard Lee ◽  
Brian Duddy ◽  
Michael Thurston ◽  
Daniel Beardslee ◽  
Ryan Enyeart
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Spark Ignition ◽  
Spark Ignition Engines ◽  
Aerial Vehicles

One-Disk Nutating-Engine Performance for Unmanned Aerial Vehicles

2004 ◽  
Vol 126 (3) ◽  
pp. 475-481 ◽  
Author(s):  
T. Korakianitis ◽  
L. Meyer ◽  
M. Boruta ◽  
H. E. McCormick
Keyword(s):  
Combustion Chamber ◽  
Unmanned Aerial Vehicles ◽  
Gas Turbines ◽  
Combustion Engine ◽  
Engine Performance ◽  
Companion Paper ◽  
Aerial Vehicles ◽  
Compression And Expansion ◽  
External Combustion ◽  
Expansion Volume

The nutating engine is a new type of internal combustion engine. The engine has unique advantages over conventional piston engines and gas turbines in small power ranges suitable for unmanned aerial vehicles (UAV), and other applications. This publication is the original presentation of the performance potential of the simplest version of the engine, a one-disk engine operating at constant compression ratio, for light airframe propulsion. In its basic configuration the core of the engine is a nutating nonrotating disk, with the center of its hub mounted in the middle of a Z-shaped shaft. The two ends of the shaft rotate, while the disk “nutates,” performs a wobbling motion without rotating around its axis. The motion of the disk circumference prescribes a portion of a sphere. A portion of the area of the disk is used for intake and compression, a portion is used to seal against a center casing, and the remaining portion is used for expansion and exhaust. The compressed air is admitted to an external accumulator, and then into an external combustion chamber before it is admitted to the power side of the disk. The external combustion chamber enables the engine to use diesel fuel in small engine sizes, giving it unique capabilities for UAV propulsion. The performance of the one-disk engine configuration for flight Mach numbers from 0 to 1 and altitudes from 0 to 20 km is presented and discussed. The performance with equal compression and expansion volume is compared with the higher-efficiency version with expansion volume higher than compression volume. A companion paper examines multidisk alternative engine configurations and load control schemes.

One-Disk Nutating-Engine Performance for Unmanned Aerial Vehicles

2001 ◽  
Author(s):  
T. Korakianitis ◽  
L. Meyer ◽  
M. Boruta ◽  
H. E. McCormick
Keyword(s):  
Combustion Chamber ◽  
Unmanned Aerial Vehicles ◽  
Gas Turbines ◽  
Combustion Engine ◽  
Engine Performance ◽  
Rotating Disk ◽  
Companion Paper ◽  
Aerial Vehicles ◽  
External Combustion ◽  
Expansion Volume

The nutating engine is a new type of internal combustion engine. The engine has unique advantages over conventional piston engines and gas turbines in small power ranges suitable for unmanned aerial vehicles (UAV), and other applications. This publication is the original presentation of the performance potential of the simplest version of the engine, a one-disk engine operating at constant compression ratio, for light airframe propulsion. In its basic configuration the core of the engine is a nutating non-rotating disk, with the center of its hub mounted in the middle of a Z-shaped shaft. The two ends of the shaft rotate, while the disk “nutates”, performs a wobbling motion without rotating around its axis. The motion of the disk circumference prescribes a portion of a sphere. A portion of the area of the disk is used for intake and compression, a portion is used to seal against a center casing, and the remaining portion is used for expansion and exhaust. The compressed air is admitted to an external accumulator, and then into an external combustion chamber before it is admitted to the power side of the disk. The external combustion chamber enables the engine to use diesel fuel in small engine sizes, giving it unique capabilities for UAV propulsion. The performance of the one-disk engine configuration for flight Mach numbers from 0 to 1 and altitudes from 0 to 20 km is presented and discussed. The performance with equal compression and expansion volume is compared with the higher-efficiency version with expansion volume higher than compression volume. A companion paper examines multi-disk alternative engine configurations and load control schemes.

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