scholarly journals Simulasi Numerik II : Distribusi Diameter Droplet pada Semprotan Biodiesel Kelapa, Jatropa Curcas dan Minyak Goreng Bekas dalam Ruang Bakar Mexican Hat

2020 ◽  
Vol 6 (2) ◽  
pp. 18-23
Author(s):  
I Gede Teddy Prananda Surya
Keyword(s):  
Diesel Fuel ◽  
Large Scale ◽  
Direct Injection ◽  
Mexican Hat ◽  
Break Up ◽  
Diameter Droplet

Abstrak   Biodiesel merupakan bahan bakar terbarukan dengan properties hampir menyerupai diesel fuel dan dapat digunakan pada motor diesel direct injection tanpa perubahan sistem bahan bakarnya. Bahan baku biodiesel yang tersedia di Indonesia antara lain kelapa, jatropa curcas dan minyak goreng bekas dapat diubah menjadi biodiesel melalui proses esterifikasi. Penelitian numerik menggunakan FLUENT 6.2 ini dilakukan pada model ruang bakar mexican hat untuk mengetahui distribusi ukuran droplet serta visualisasi semprotan dari ketiga jenis biodiesel tersebut. Pemodelan turbulen yang digunakan adalah RNG k-ε karena dapat memprediksi struktur large scale yang diproduksi oleh semprotan dan squish flow sedangkan pemodelan break-up menggunakan WAVE karena semprotan ini berlangsung dalam angka Weber yang tinggi. Hasil numerik membuktikan bahwa biodiesel minyak goreng bekas memiliki droplet berdiameter lebih besar daripada biodiesel kelapa atau jatropa curcas karena memiliki tegangan permukaan tinggi. Diameter partikel akan berkurang saat penetrasi semakin jauh karena pengaruh gaya aerodinamik yang bekerja pada droplet dan droplet tadi pecah setelah bertumbukan dengan dinding piston.   Kata kunci : diameter droplet, SMD, biodiesel

Spray Break-Up Process of Diesel Fuel Investigated Close to the Nozzle

1997 ◽  
Vol 24 (1-3) ◽  
pp. 251-260 ◽  
Author(s):  
A. Fath ◽  
K.-U. Munch ◽  
Alfred Leipertz
Keyword(s):  
Diesel Fuel ◽  
Break Up

Explorative Investigation on Cashew Nut Shell Liquid Biodiesel blended with Ethanol and Hydrogen in Direct Injection (DI) Diesel Engine and prediction through Artificial Neural Network

2021 ◽  
Author(s):  
Thanigaivelan V ◽  
Lavanya R
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Direct Injection ◽  
Cashew Nut Shell Liquid ◽  
Single Cylinder ◽  
Direct Injection Diesel Engine ◽  
Cashew Nut ◽  
Di Diesel Engine ◽  
Artificial Neural ◽  
Cashew Nut Shell

Abstract Emission from the DI diesel engine is series setback for environment viewpoint. Intended for that investigates for alternative biofuel is persuaded. The important hitches with the utilization of biofuels and their blends in DI diesel engines are higher emanations and inferior brake-thermal efficiency as associated to sole diesel fuel. In this effort, Cashew nut shell liquid (CNSL) biodiesel, hydrogen and ethanol (BHE) mixtures remained verified in a direct-injection diesel engine with single cylinder to examine the performance and discharge features of the engine. The ethanol remained supplemented 5%, 10% and 15% correspondingly through enhanced CNSL as well as hydrogen functioned twin fuel engine. The experiments done in a direct injection diesel engine with single-cylinder at steadystate conditions above the persistent RPM (1500RPM). Throughout the experiment, emissions of pollutants such as fuel consumption rate (SFC), hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NOx) and pressure of the fuel were also measured. cylinders. The experimental results show that, compared to diesel fuel, the braking heat of the biodiesel mixture is reduced by 26.79-24% and the BSFC diminutions with growing addition of ethanol from the CNSL hydrogen mixture. The BTE upsurges thru a rise in ethanol proportion with CNSL hydrogen mixtures. Finally, the optimum combination of ethanol with CNSL hydrogen blends led to the reduced levels of HC and CO emissions with trivial upsurge in exhaust gas temperature and NOx emissions. This paper reconnoiters the routine of artificial neural networks (ANN) to envisage recital, ignition and discharges effect.

Effect of n-heptane and n-decane on exhaust odour in direct injection diesel engines

2005 ◽  
Vol 219 (4) ◽  
pp. 565-571 ◽  
Author(s):  
M M Roy
Keyword(s):  
Direct Effect ◽  
Diesel Fuel ◽  
Diesel Engines ◽  
Ignition Delay ◽  
Boiling Point ◽  
Alternative Fuels ◽  
Direct Injection ◽  
Cetane Number ◽  
Mixture Formation ◽  
Incomplete Combustion

This study investigated the effect of n-heptane and n-decane on exhaust odour in direct injection (DI) diesel engines. The prospect of these alternative fuels to reduce wall adherence and overleaning, major sources of incomplete combustion, as well as odorous emissions has been investigated. The n-heptane was tested as a low boiling point fuel that can improve evaporation as well as wall adherence. However, the odour is a little worse with n-heptane and blends than that of diesel fuel due to overleaning of the mixture. Also, formaldehyde (HCHO) and total hydrocarbon (THC) in the exhaust increase with increasing n-heptane content. The n-decane was tested as a fuel with a high cetane number that can improve ignition delay, which has a direct effect on wall adherence and overleaning. However, with n-decane and blends, the odour rating is about 0.5-1 point lower than for diesel fuel. Moreover, the aldehydes and THC are significantly reduced. This is due to less wall adherence and proper mixture formation.

scholarly journals THE EFFECT OF DIESEL-BIODIESEL BLENDS ON THE PERFORMANCE AND EXHAUST EMISSIONS OF A DIRECT INJECTION OFF-ROAD DIESEL ENGINE

Transport ◽  
2014 ◽  
Vol 29 (4) ◽  
pp. 440-448 ◽  
Author(s):  
Tomas Mickevičius ◽  
Stasys Slavinskas ◽  
Slawomir Wierzbicki ◽  
Kamil Duda
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Direct Injection ◽  
Engine Performance ◽  
Exhaust Emissions ◽  
Bench Test ◽  
Maximum Pressure ◽  
Cylinder Pressure ◽  
Biodiesel Blends ◽  
Performance And Emission

This paper presents a comparative analysis of the diesel engine performance and emission characteristics, when operating on diesel fuel and various diesel-biodiesel (B10, B20, B40, B60) blends, at various loads and engine speeds. The experimental tests were performed on a four-stroke, four-cylinder, direct injection, naturally aspirated, 60 kW diesel engine D-243. The in-cylinder pressure data was analysed to determine the ignition delay, the Heat Release Rate (HRR), maximum in-cylinder pressure and maximum pressure gradients. The influence of diesel-biodiesel blends on the Brake Specific Fuel Consumption (bsfc) and exhaust emissions was also investigated. The bench test results showed that when the engine running on blends B60 at full engine load and rated speed, the autoignition delay was 13.5% longer, in comparison with mineral diesel. Maximum cylinder pressure decreased about 1–2% when the amount of Rapeseed Methyl Ester (RME) expanded in the diesel fuel when operating at full load and 1400 min–1 speed. At rated mode, the minimum bsfc increased, when operating on biofuel blends compared to mineral diesel. The maximum brake thermal efficiency sustained at the levels from 0.3% to 6.5% lower in comparison with mineral diesel operating at full (100%) load. When the engine was running at maximum torque mode using diesel – RME fuel blends B10, B20, B40 and B60 the total emissions of nitrogen oxides decreased. At full and moderate load, the emission of carbon monoxide significantly raised as the amount of RME in fuel increased.

Landscape development in western and central Dronning Maud Land, East Antarctica

2001 ◽  
Vol 13 (3) ◽  
pp. 302-311 ◽  
Author(s):  
Jens-Ove Näslund
Keyword(s):  
Large Scale ◽  
High Elevation ◽  
Continental Margins ◽  
Landscape Development ◽  
Ice Streams ◽  
The North ◽  
Ice Stream ◽  
Dronning Maud Land ◽  
Break Up

Large-scale bedrock morphology and relief of two key areas, the Jutulsessen Nunatak and the Jutulstraumen ice stream are used to discuss glascial history and landscape development in western and central Dronning Maud Land, Antarctica. Two main landform components were identified: well-defined summit plateau surfaces and a typical alpine glacial landscape. The flat, high-elevation plateau surfaces previously were part of one or several continuous regional planation surfaces. In western Dronning Maud Land, overlying cover rocks of late Palaeozoic age show that the planation surface(s) existed in the early Permian, prior to the break-up of Gondwana. A well-develoment escarpment, a mega landform typical for passive continental margins, bounds the palaeosurface remnants to the north for a distance of at least 700 km. The Cenozoic glacial landscape, incised in the palaeosurface and escarpment, is exemplified by Jutulsessen Nunatak, where a c. 1.2 km deep glacial valley system is developed. However, the prominent Penck-Jutul Trough represents some of the deepest dissection of the palaeosurface. This originally tectonic feature is today occupied by the Jutulstraumen ice stream. New topographic data show that the bed of the Penck-Jutul Trough is situated 1.9±1.1 km below sea level, and that the total landscape relief is at least 4.2 km. Today's relief is a result of several processes, including tectonic faulting, subaerial weathering, fluvial erosion, and glacial erosion. It is probable that erosion by ice streams has deepened the tectonic troughs of Dronning Maud Land since the onset of ice sheet glaciation in the Oligocene, and continues today. An attempt is made to identify major events in the long-term landscape development of Dronning Maud Land, since the break-up of the Gondwana continent.

scholarly journals Effects of Oxygenated Additives with Diesel on the Performance of D I Diesel Engine

2019 ◽  
pp. 1-9 ◽  
Author(s):  
P. Venkateswara Rao ◽  
S. Ramesh ◽  
S. Anil Kumar
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Direct Injection ◽  
Primary Objective ◽  
Nox Emissions ◽  
Oxides Of Nitrogen ◽  
Smoke Emission ◽  
Oxygenated Additives ◽  
Blend Fuel ◽  
Fuel Formulation

The primary objective of this work is to reduce the particulate matter (PM) or smoke emission and oxides of nitrogen (NOx emissions) the two important harmful emissions and to increase the performance of diesel engine by using oxygenated additives with diesel as blend fuel. Formulation of available diesel fuel with additives is an advantage than considering of engine modification for improvement of higher output. From the available additives, three oxygenates are selected for experimentation by considering many aspects like cost, content of oxygen, flashpoint, solubility, seal etc. The selected oxygenates are Ethyl Aceto Acetate (EAA), Diethyl Carbonate (DEC), Diethylene Glycol (DEG). These oxygenates are blended with diesel fuel in proportions of 2.5%, 5% and 7.5% by volume and experiments were conducted on a single cylinder naturally aspirated direct injection diesel engine. From the results the conclusion are higher brake power and lower BSFC obtained for DEC blends at 7.5% of additive as compared to EAA, DEG and diesel at full load. In case of DEC blends the smoke emission is lower, whereas NOx emissions are very low in case of EAA additive blend fuels. The DEC can be considered is the best oxygenating additive to be blend with diesel in a proportion of 7.5% by volume.

Simulation of cavitation in outward-opening piezo-type pintle injector nozzles

2008 ◽  
Vol 222 (10) ◽  
pp. 1895-1910 ◽  
Author(s):  
E Giannadakis ◽  
D Papoulias ◽  
A Theodorakakos ◽  
M Gavaises
Keyword(s):  
Bubble Growth ◽  
Large Scale ◽  
Direct Injection ◽  
Bubble Formation ◽  
Needle Valve ◽  
Transient Effects ◽  
Cavitation Model ◽  
Gasoline Engines ◽  
Opening And Closing ◽  
Vapour Film

The onset and development of cavitation in the annular needle seat passage of piezo-driven outward-opening pintle injector nozzles used with spray-guided direct-injection gasoline engines are studied using a Eulerian-Lagrangian computational fluid dynamics cavitation model. Cavitation is formed because of the fluid acceleration taking place at the needle sealing area and it has been found to be affected by its geometric details. Various submodels for nucleation and bubble formation, further bubble growth and collapse, as well as bubble break-up and transport are incorporated into the model. Qualitative model validation is performed against experimental data reported elsewhere in large-scale nozzle replicas, showing similar cavitation patterns to be formed. These consist of vapour pockets rather than a continuous vapour film and develop transiently in a rather chaotic manner around the circumferential needle sealing area, even under stationary geometry and fixed-flowrate conditions. Further transient effects associated with the fast opening and closing of the piezo-controlled needle valve are also presented.

Spray and Combustion Characteristics of Biodiesel∕Diesel Blended Fuel in a Direct Injection Common-Rail Diesel Engine

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Hyun Kyu Suh ◽  
Hyun Gu Roh ◽  
Chang Sik Lee
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Direct Injection ◽  
Injection Rate ◽  
Combustion Characteristics ◽  
Biodiesel Fuel ◽  
Injection Timing ◽  
Pilot Injection ◽  
Blended Fuel ◽  
Conventional Diesel Fuel

The aim of this work is to investigate the effect of the blending ratio and pilot injection on the spray and combustion characteristics of biodiesel fuel and compare these factors with those of diesel fuel in a direct injection common-rail diesel engine. In order to study the factors influencing the spray and combustion characteristics of biodiesel fuel, experiments involving exhaust emissions and engine performance were conducted at various biodiesel blending ratios and injection conditions for engine operating conditions. The macroscopic and microscopic spray characteristics of biodiesel fuel, such as injection rate, split injection effect, spray tip penetration, droplet diameter, and axial velocity distribution, were compared with the results from conventional diesel fuel. For biodiesel blended fuel, it was revealed that a higher injection pressure is needed to achieve the same injection rate at a higher blending ratio. The spray tip penetration of biodiesel fuel was similar to that of diesel. The atomization characteristics of biodiesel show that it has higher Sauter mean diameter and lower spray velocity than conventional diesel fuel due to high viscosity and surface tension. The peak combustion pressures of diesel and blending fuel increased with advanced injection timing and the combustion pressure of biodiesel fuel is higher than that of diesel fuel. As the pilot injection timing is retarded to 15deg of BTDC that is closed by the top dead center, the dissimilarities of diesel and blending fuels combustion pressure are reduced. It was found that the pilot injection enhanced the deteriorated spray and combustion characteristics of biodiesel fuel caused by different physical properties of the fuel.

scholarly journals The impact of secondary ice production on Arctic stratocumulus

2020 ◽  
Vol 20 (3) ◽  
pp. 1301-1316
Author(s):  
Georgia Sotiropoulou ◽  
Sylvia Sullivan ◽  
Julien Savre ◽  
Gary Lloyd ◽  
Thomas Lachlan-Cope ◽  
...  
Keyword(s):  
Large Scale ◽  
Cloud Condensation Nuclei ◽  
The Arctic ◽  
Computationally Efficient ◽  
Eddy Simulation ◽  
Scale Models ◽  
Break Up ◽  
Ice Production ◽  
Low Sensitivity ◽  
The Impact

Abstract. In situ measurements of Arctic clouds frequently show that ice crystal number concentrations (ICNCs) are much higher than the number of available ice-nucleating particles (INPs), suggesting that secondary ice production (SIP) may be active. Here we use a Lagrangian parcel model (LPM) and a large-eddy simulation (LES) to investigate the impact of three SIP mechanisms (rime splintering, break-up from ice–ice collisions and drop shattering) on a summer Arctic stratocumulus case observed during the Aerosol-Cloud Coupling And Climate Interactions in the Arctic (ACCACIA) campaign. Primary ice alone cannot explain the observed ICNCs, and drop shattering is ineffective in the examined conditions. Only the combination of both rime splintering (RS) and collisional break-up (BR) can explain the observed ICNCs, since both of these mechanisms are weak when activated alone. In contrast to RS, BR is currently not represented in large-scale models; however our results indicate that this may also be a critical ice-multiplication mechanism. In general, low sensitivity of the ICNCs to the assumed INP, to the cloud condensation nuclei (CCN) conditions and also to the choice of BR parameterization is found. Finally, we show that a simplified treatment of SIP, using a LPM constrained by a LES and/or observations, provides a realistic yet computationally efficient way to study SIP effects on clouds. This method can eventually serve as a way to parameterize SIP processes in large-scale models.

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