scholarly journals Evaluation of the effect of variable compression ratios performance on opposed piston 2-stroke engine

2017 ◽  
Vol 171 (4) ◽  
pp. 97-106
Author(s):  
Ali ALQAHTANI ◽  
Miroslaw WYSZYNSKI ◽  
Pawel MAZURO ◽  
Hongming XU

Numerous skills involving the introduction of (OP) opposed piston engine have been developed in the recent past. Indeed, novel techniques can help to improve the performance of the engine. The aim of this paper is to model and simulate a simple single-cylinder two-stroke opposed-piston engine and minimise fuel consumption and heat loss, using the software programme AVL BOOST™. AVL BOOST is an engine modelling software, which analyses the performance of a modelled single cylinder two-stroke opposed-piston engine by changing desired parameters. In order to meet this aim, experimental results from a unique engine are used to make a comparison with the results obtained from AVL BOOST model. Six combinations of compression ratios (12, 13.5, 15, 16.5, 18 and 19.5) are analysed in this study with the engine speed running at 420 rpm and 1500 rpm. In addition to the compression ratios, the effect of stroke-to-bore (S/B) ratios on OP2S performance is investigated. Various values of S/B ratios, whilst maintaining a constant swept volume, port geometry and combustion timing, and their effect on fuel consumption and heat loss are analysed in this study. A comparison between the two engine speeds with increasing combinations of compression ratios, and the S/B ratios revealed minimal differences in peak pressure, peak temperature, IMEP, ISFC, indicated efficiency and total heat loss. Detailed analyses of these parameters are highlighted in discrete sections of this paper.

ROTOR ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 49
Author(s):  
Muhamad Hafidz Firdaus Priatama ◽  
Imron Rosyadi ◽  
Yusvardi Yusuf

The use of a fuel mixture of gasoline and ethanol can reduce the PM2.5 (Particulate Matter) value in the air by 0.3-0.4 µg m-3. This research aims to see the performance of a 4-stroke engine 113cc in standard conditions using a mixture of premium and ethanol. This research learns 5 types of mixture, E0, E10, E15, E20, and E25. The fuels was tested at 5 engine speed 4000, 4500, 5000, 5500, and 6000 rpm, at prony brake dynamometer to measuring performance, fuel consumption and Specific Fuel Consumption (SFC). The results of research show that the highest torque and power is the E15 mixture, that is 8.90 Nm at 5500 rpm and the power obtained is 5.529 kW at 6000 rpm. Meanwhile, the lowest fuel consumption value is found in the E10 with a value of 169.78 gr/hour at 4500 rpm. The lowest SFC value of all fuels is the E15 at 5000 rpm on 27.565 gr/kW.h. This is the lowest of any other fuel, because the  Research Octane Number value is following the compression ratio of the engine, so there is no delay in ignition symptoms that occur during the combustion system. The viscosity value also contributes to the difference in data.


Author(s):  
V. S. KUMBHAR ◽  
D. G. MALI ◽  
P. H. PANDHARE ◽  
R. M. MANE

Alcohols, basically ethanol is considered as a leading alternative fuel for automotive application because of its ability to reduce the air pollution and cost of the fuel. This paper investigates the effect of lower ethanol gasoline blends (up to 20% by volume) on performance and emission characteristics of the single cylinder four stroke SI engine. Tests were carried out for power, torque, fuel consumption and brake mean effective pressure, while exhaust emissions were analyzed for CO, CO2, and HC by using different ethanol gasoline blends on volume basis at wide open throttle and variable engine speed from 4000 to 8000 rpm. Results were compared with the pure gasoline. It showed that as the ethanol content increases the power, torque, fuel consumption, brake mean effective pressure and CO2 emission while reduces HC and CO emission.


Author(s):  
Samy A. Alkhayat ◽  
Manan J. Trivedi ◽  
Naeim A. Henein ◽  
Sampad Mukhopadhyay ◽  
Peter Schihl

The goal of this investigation is to compare the validation of Sasol-IPK and its surrogate fuel in the IQT and in an actual diesel engine. The surrogate fuel is composed of three components (46% iso-cetane, 44% decalin and 10% n-nonane on a volume basis). IQT experiments were conducted as per ASTM D6890-10a. Engine experiments were conducted at 1500 RPM, two engine loads, and two injection timings. Analysis of the ignition delay, peak pressure, peak RHR and other combustion phasing parameters, showed a closer match in IQT than in the diesel engine. This investigation suggests that validation in a single cylinder diesel engine should be a part of the surrogate validation, particularly for low ignition quality fuels.


2020 ◽  
Vol 3 (1) ◽  
pp. 20-26
Author(s):  
Farid Majedi ◽  
Denik Setiyaningrum ◽  
Setyono M. T. Hidayahtullah ◽  
Aries Abbas

On a single-cylinder diesel engine, injection pressure can be adjusted by changing the thickness of the injector shim. In this study, the injection pressure of 180 bar (standard), 190 bar (+1mm shim), and 210 bar (+2mm shim) was examined on a typical single-cylinder diesel engine with pure diesel fuel. The tests carried out at a constant engine speed of 1500 rpm with load variations of 650, 1300, 1950, and 3600 Watts to investigate the effect of injection pressure on output power, brake thermal efficiency (BTE), specific fuel consumption (SFC) and opacity. The results showed that increasing injection pressure could increase the output power by 19.3% and 17.4% by adding 1 mm and 2 mm shims, respectively. SFC decreased 1.97% and 12.3% compared to standard conditions and opacity with 2 mm shim was lower than 1 mm shim. In conclusion, increasing the injection pressure from 180 to 210 bar by adding 2 mm shim can improve the performance of a single cylinder diesel engine, which includes output power, brake thermal efficiency (BTE), specific fuel consumption (SFC) and opacity.


2021 ◽  
Vol 1068 (1) ◽  
pp. 012016
Author(s):  
Hazim Sharudin ◽  
N.A. Rahim ◽  
N.I. Ismail ◽  
Sharzali Che Mat ◽  
Nik Rosli Abdullah ◽  
...  

Author(s):  
Teja Gonguntla ◽  
Robert Raine ◽  
Leigh Ramsey ◽  
Thomas Houlihan

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.


2021 ◽  
pp. 004051752110265
Author(s):  
Huipu Gao ◽  
Anthoney Shawn Deaton ◽  
Xiaomeng Fang ◽  
Kyle Watson ◽  
Emiel A DenHartog ◽  
...  

The goal of this research was to understand how firefighter protective suits perform in different operational environments. This study used a sweating guarded hotplate to examine the effect of environmental temperature (20–45°C) and relative humidity (25–85% RH) on evaporative heat loss through firefighter turnout materials. Four firefighter turnout composites containing three different bi-component (semi-permeable) and one microporous moisture barriers were selected. The results showed that the evaporative resistance of microporous moisture barrier systems was independent of environmental testing conditions. However, absorbed moisture strongly affected evaporative heat loss through semi-permeable moisture barriers coated with a layer of nonporous hydrophilic polymer. Moisture absorption in mild environment (20–25°C) tests, or when testing at high humidity (>85% RH), significantly increased water vapor transmission in semi-permeable turnout systems. It was also found that environmental conditions used in the total heat loss (THL) test (25°C and 65% RH) produced moisture condensation in bi-component barrier systems, making them appear more breathable than could be expected when worn in hotter environments. Regression models successfully qualified the relationships between moisture uptake levels in semi-permeable barrier systems and evaporative resistance and THL. These findings reveal the limitations in relying on THL, the heat strain index currently called for by the NFPA 1971 Standard for Structural Firefighter personal protective equipment, and supports the need to measure turnout evaporative resistance at 35°C (Ret), in addition to THL at 25°C.


1971 ◽  
Vol 49 (5) ◽  
pp. 767-774 ◽  
Author(s):  
M. Berger ◽  
J. S. Hart ◽  
O. Z. Roy

Pulmonary ventilation and temperature of expired air and of the respiratory passages has been measured by telemetry during flight in the black duck (Anas rubripes) and the respiratory water and heat loss has been calculated.During flight, temperature of expired air was higher than at rest and decreased with decreasing ambient temperatures. Accordingly, respiratory water loss as well as evaporative heat loss decreased at low ambient temperatures, whereas heat loss by warming of the inspired air increased. The data indicated respiratory water loss exceeded metabolic water production except at very low ambient temperatures. In the range between −16 °C to +19 °C, the total respiratory heat loss was fairly constant and amounted to 19% of the heat production. Evidence for the independence of total heat loss and production from changes in ambient temperature during flight is discussed.


Author(s):  
J. K. Woodard ◽  
G. E. Johnson ◽  
R. L. Lott

Abstract The design of a turbocharged, gasoline fueled, four-stroke engine is considered with the goal of selecting design and operating variables to minimize fuel consumption. The development of the engine simulation code and the effect of model assumptions on the results are presented. The optimization includes constraints on detonation, exhaust emissions, and torque. Variables are bounded to assure the validity of the simulation. A number of observations about the interaction between the thermo-fluid model and the nonlinear programming algorithm are made and general strategies to enhance the optimization under such circumstances are discussed. The method is illustrated by exploring the design of a turbocharged Buick V-6 engine on an IBM PC/AT personal computer. Stock design variables, and operating variables that provided a design away from the constraints imposed by torque, emission, and detonation were chosen as the starting point for the optimization. Application of the optimization strategy resulted in an 18 percent reduction in predicted fuel consumption at 50 miles per hour. Significant specific recommendations included a reduction in combustion chamber volume, an increase in intake manifold pressure, an increase in intake duration, a decrease in exhaust duration, and relatively small changes in valve geometry. The paper clearly demonstrates that it is feasible to do relatively sophisticated engineering design and optimization on personal computers, and it sets the stage for further work in this area.


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