scholarly journals Numerical Investigation of the Characteristics of the In-Cylinder Air Flow in a Compression-Ignition Engine for the Application of Emulsified Biofuels

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1517
Author(s):  
Mohd Fadzli Hamid ◽  
Mohamad Yusof Idroas ◽  
Mazlan Mohamed ◽  
Shukriwani Sa'ad ◽  
Teoh Yew Heng ◽  
...  
Keyword(s):  
Fuel Injection ◽  
Numerical Study ◽  
Guide Vane ◽  
Engine Performance ◽  
3D Analysis ◽  
Compression Ignition Engine ◽  
Ansys Fluent ◽  
Start Of Injection ◽  
Crank Angle ◽  
Start Of Combustion

This paper presents a numerical analysis of the application of emulsified biofuel (EB) to diesel engines. The study performs a numerical study of three different guide vane designs (GVD) that are incorporated with a shallow depth re-entrance combustion chamber (SCC) piston. The GVD variables were used in three GVD models with different vane heights, that is, 0.2, 0.4 and 0.6 times the radius of the intake runner (R) and these were named 0.20R, 0.40R and 0.60R. The SCC piston and GVD model were designed using SolidWorks 2017, while ANSYS Fluent version 15 was used to perform cold flow engine 3D analysis. The results of the numerical study showed that 0.60R is the optimum guide vane height, as the turbulence kinetic energy (TKE), swirl ratio (Rs), tumble ratio (RT) and cross tumble ratio (RCT) in the fuel injection region improved from the crank angle before the start of injection (SOI) and start of combustion (SOC). This is essential to break up the heavier-fuel molecules of EB so that they mix with the surrounding air, which eventually improves the engine performance.

scholarly journals Numerical Investigation of Fluid Flow and In-Cylinder Air Flow Characteristics for Higher Viscosity Fuel Applications

Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 439 ◽  
Author(s):  
Mohd Fadzli Hamid ◽  
Mohamad Yusof Idroas ◽  
Shukriwani Sa’ad ◽  
Teoh Yew Heng ◽  
Sharzali Che Mat ◽  
...  
Keyword(s):  
Guide Vane ◽  
Flow Characteristics ◽  
Engine Performance ◽  
Intake Manifold ◽  
3D Analysis ◽  
Ansys Fluent ◽  
Ic Engine ◽  
Cold Flow ◽  
Ci Engine ◽  
Combustion Processes

Generally, the compression ignition (CI) engine that runs with emulsified biofuel (EB) or higher viscosity fuel experiences inferior performance and a higher emission compared to petro diesel engines. The modification is necessary to standard engine level in order to realize its application. This paper proposes a guide vane design (GVD), which needs to be installed in the intake manifold, is incorporated with shallow depth re-entrance combustion chamber (SCC) pistons. This will organize and develop proper in-cylinder airflow to promote better diffusion, evaporation and combustion processes. The model of GVD and SCC piston was designed using SolidWorks 2017; while ANSYS Fluent version 15 was utilized to run a 3D analysis of the cold flow IC engine. In this research, seven designs of GVD with the number of vanes varied from two to eight vanes (V2–V8) are used. The four-vane model (V4) has shown an excellent turbulent flow as well as swirl, tumble and cross tumble ratios in the fuel-injected region compared to other designs. This is indispensable to break up heavier fuel molecules of EB to mix with the air that will eventually improve engine performance.

Combustion Characteristics of Methane Direct Injection Engine Under Various Injection Timings and Injection Pressures

2017 ◽  
Vol 139 (8) ◽  
Author(s):  
Jingeun Song ◽  
Mingi Choi ◽  
Daesik Kim ◽  
Sungwook Park
Keyword(s):  
Fuel Injection ◽  
Direct Injection ◽  
Injection Pressure ◽  
Combustion Characteristics ◽  
Direct Injection Engine ◽  
Optical Engine ◽  
Start Of Injection ◽  
Crank Angle ◽  
Combustion Speed ◽  
Injection Pressures

The performance of a methane direct injection engine was investigated under various fuel injection timings and injection pressures. A single-cylinder optical engine was used to acquire in-cylinder pressure data and flame images. An outward-opening injector was installed at the center of the cylinder head. Experimental results showed that the combustion characteristics were strongly influenced by the end of injection (EOI) timing rather than the start of injection (SOI) timing. Late injection enhanced the combustion speed because the short duration between the end of injection and the spark-induced strong turbulence. The flame propagation speeds under various injection timings were directly compared using crank-angle-resolved sequential flame images. The injection pressure was not an important factor in the combustion; the three injection pressure cases of 0.5, 0.8, and 1.1 MPa yielded similar combustion trends. In the cases of late injection, the injection timings of which were near the intake valve closing (IVC) timing, the volumetric efficiency was higher (by 4%) than in the earlier injection cases. This result implies that the methane direct injection engine can achieve higher torque by means of the late injection strategy.

scholarly journals NUMERICAL STUDY: COMPARISON THE EFFECT OF RATIO LENGTH AND DIAMETER GUIDE VANE OF AIR FLOW ON OUTLET DUCTING

2020 ◽  
Vol 5 (2) ◽  
pp. 150-159
Author(s):  
Fajar Anggara
Keyword(s):  
Numerical Study ◽  
Guide Vane ◽  
Air Flow ◽  
Ansys Fluent

Guide vane sangat berperan dalam pengkondisian pola aliran dan kecepatan fluida sebelum melewati sudu turbin. Dengan konfigurasi pemasangan turbin sumbu aksial sesudah kondensor ac, dibutuhkan guide vane yang mampu menghasilkan kecepatan tinggi pada daerah dekat dinding ducting. Untuk itu penelitian ini dilakukan untuk membandingkan pengaruh rasio dimensi panjang dan diameter menggunakan ANSYS FLUENT 17. Variasi dimensi geometri guide vane dibagi menjadi dua tipe, dimana masing-masing memiliki tiga variasi geometri. Tipe 1dengan rasio dimensi panjang terdiri atas variasi A, B dan C sedangkan tipe 2 dengan rasio dimensi diameter, variasinya adalah D, E dan F. Hasil memperlihatkan bahwa variasi B dan F menghasilkan kecepatan paling tinggi di tipenya. Hal ini karena efek percepatan maksimal pada variasi B dan sudut terkecil guide vane akan mengurangi gaya gesek pada variasi F.

Numerical Study on Thermal Choke Behaviors Driven by Various Rocket Operations in an RBCC Engine in Ramjet Mode

2020 ◽  
Vol 37 (3) ◽  
pp. 305-317
Author(s):  
Lei Shi ◽  
Da Gao ◽  
Liangliang Xing ◽  
Fei Qin ◽  
Guoqiang He
Keyword(s):  
Fuel Injection ◽  
Numerical Study ◽  
Engine Performance ◽  
Generation Process ◽  
Two Dimensional ◽  
Integration Model ◽  
Numerical Studies ◽  
Rocket Plume ◽  
Secondary Fuel ◽  
Sonic Speed

AbstractThermal choke is commonly employed in a fixed geometry RBCC combustor to eliminate the need for physically variable exit geometry. This paper proposed detailed numerical studies based on a two-dimensional integration model to characterize thermal choke behaviors driven by various embedded rocket operations in an RBCC engine at Mach 4 in ramjet mode. The influences of different embedded rocket operations as well as the corresponding secondary fuel injection adjustment on thermal choke generation process, the related thermal throat feature, and the engine performance are analyzed. Operations of embedded rocket bring significant effects on the thermal choke behaviors: (1) the thermal throat feature becomes much more irregular influenced by the rocket plume; (2) the occupancy range in the combustor is significantly lengthened; (3) the asynchrony of the flow in different regions accelerating to sonic speed becomes much more significant; (4) as the rocket throttling ratio decreases, the thermal choke position constantly moves upstream integrally, and the heated flow in the top region that is directly affected by the rocket plume reaches sonic speed more rapidly. Finally, we can conclude that appropriate secondary fuel injection adjustment can provide a higher integration thrust for the RBCC engine with the embedded rocket operating, while the thermal choke is stably controlled, and the increased heat release and combustion pressure are well balanced by the variations of pre-combustion shocks in the inlet isolator.

Durability Testing of Biomass Based Oxygenated Fuel Components in a Compression Ignition Engine

2017 ◽  
Author(s):  
Marc E. Baumgardner ◽  
Arunachalam Lakshminarayanan ◽  
Daniel B. Olsen ◽  
Matthew A. Ratcliff ◽  
Robert L. McCormick ◽  
...  
Keyword(s):  
Diesel Fuel ◽  
Fuel Injection ◽  
Engine Performance ◽  
Engine Oil ◽  
Long Term Effects ◽  
Compression Ignition Engine ◽  
Engine Operation ◽  
Minimal Impact ◽  
Carbon Buildup ◽  
The Impact

Blending cellulosic biofuels with traditional petroleum-derived fuels results in transportation fuels with reduced carbon footprints. Many cellulosic fuels rely on processing methods that produce mixtures of oxygenates which must be upgraded before blending with traditional fuels. Complete oxygenate removal is energy-intensive and it is likely that such biofuel blends will necessarily contain some oxygen content to be economically viable. Previous work by our group indicated that diesel fuel blends with low levels (<4%-vol) of oxygenates resulted in minimal negative effects on short-term engine performance and emissions. However, little is known about the long-term effects of these compounds on engine durability issues such as the impact on fuel injection, in-cylinder carbon buildup, and engine oil degradation. In this study, four of the oxygenated components previously tested were blended at 4%-vol in diesel fuel and tested with a durability protocol devised for this work consisting of 200 hrs of testing in a stationary, single-cylinder, Yanmar diesel engine operating at constant load. Oil samples, injector spray patterns, and carbon buildup from the injector and cylinder surfaces were analyzed. It was found that, at the levels tested, these fuels had minimal impact on the overall engine operation, which is consistent with our previous findings.

NUMERICAL STUDY OF HYDROGEN FUEL COMBUSTION IN COMPRESSION IGNITION ENGINE UNDER ARGON-OXYGEN ATMOSPHERE

2016 ◽  
Vol 78 (6-10) ◽  
Author(s):  
Nik Muhammad Hafiz ◽  
Mohd Radzi Abu Mansor ◽  
Wan Mohd Faizal Wan Mahmood ◽  
Fadzli Ibrahim ◽  
Shahrir Abdullah ◽  
...  
Keyword(s):  
Numerical Study ◽  
High Volume ◽  
Compression Ignition ◽  
Hydrogen Fuel ◽  
Compression Ignition Engine ◽  
Complete Combustion ◽  
Start Of Injection ◽  
Auto Ignition ◽  
Oxygen Medium ◽  
Carbon Dioxide Co2

Gas emissions from automobiles are one of the major causes of air pollution in our environment today. In fact, emissions of carbon dioxide (CO2), a product of complete combustion, has become a significant factor of the global warming effect. Hydrogen, which is a renewable energy, is regarded as a promising energy to solve this problem since the final product of hydrogen (H2) combustion, is water (H2O). However, the reaction of hydrogen fuels in the air under high temperature conditions produces a high volume of harmful nitrogen oxide (NOx). Furthermore, the high auto-ignition temperature of H2 makes it difficult to ignite in a compression ignition engine in normal air. In this research, argon (Ar) is used to replace nitrogen (N2), in order to eliminate NOx and enhance combustion. Simulation for this research was conducted using Converge, computational fluid dynamics software that is based on Yanmar TF90M compression ignition engine parameters. The simulation process was initially conducted with normal air (N2-O2) as the medium of combustion; but later it was replaced with an argon-oxygen (Ar-O2) atmosphere to investigate the ignition possibility of hydrogen fuel. Hydrogen was injected at 9.95 MPa at the start of injection (SOI) at 18º BTDC. The results show that, by employing the same parameters for both simulations in normal air and argon-oxygen mediums, the combustion of hydrogen only occurred in the argon-oxygen medium. However, no combustion took place in normal air. It is therefore concluded that an argon-oxygen medium is applicable for direct hydrogen injection in a compression ignition engine.

Numerical Investigation of Using 1-Butanol in a Port Fuel Injection Spark Ignition Engine

2012 ◽  
Vol 588-589 ◽  
pp. 319-322
Author(s):  
Ye Jian Qian ◽  
Zhi Fang Chen ◽  
Chun Mei Wang
Keyword(s):  
Equivalence Ratio ◽  
Fuel Injection ◽  
Numerical Study ◽  
Engine Performance ◽  
Maximum Level ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Nox Emissions ◽  
Performance And Emission ◽  
Port Fuel Injection

A numerical study is conducted in a port fuel-injection, spark-ignition engine fuelled with 1-butanol at different fuel/air equivalence ratios and inlet air temperatures. The effect of fuel/air equivalence ratio and inlet air temperature on the engine performance and emission characteristics is analyzed. The modeling results show that the incylinder pressure and temperature increases with the increase of fuel/air equivalence ratio. The slightly lean mixtures offer the maximum level of NOX emissions. In addition, preheating the inlet air can increase the incylinder pressure peak value and NOX emissions.

scholarly journals Numerical study of fuel and turbulence distributions in an automotive-sized scavenged pre-chamber

2019 ◽  
Vol 176 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Michele BOLLA ◽  
Evgeniy SHAPIRO ◽  
Maria KOTZAGIANNI ◽  
Panagiotis KYRTATOS ◽  
Nick TINEY ◽  
...  
Keyword(s):  
Fuel Injection ◽  
Numerical Study ◽  
Engine Performance ◽  
Injection Rate ◽  
Navier Stokes ◽  
Experimental Investigations ◽  
Test Case ◽  
Ensemble Averaging ◽  
Lean Burn ◽  
Flame Development

This article presents a numerical study of the fuel and turbulence distributions in a pre-chamber at spark-time. The study has been conducted in the framework of the H2020 Gas-On project, dealing with the development of a lean-burn concept for an automotive-sized gas engine equipped with a scavenged pre-chamber. The test case considered studies a 7-hole pre-chamber with circumferentially-tilted orifices mounted on the cylinder head of a rapid compression-expansion machine (RCEM), consistent with the experimental test rig installed at ETH Zurich. An accurate description of turbulence and fuel distributions are key quantities determining the early flame development within the pre-chamber. Both quantities have an influence on the overall combustion characteristics and therefore on the engine performance. For this purpose, computational fluid dynamics (CFD) is employed to complement experimental investigations in terms of data completeness. The performance of the Reynolds-averaged Navier-Stokes (RANS)-based turbulence model is compared with large-eddy simulation (LES) through ensemble averaging of multiple LES realizations, in which the fuel injection rate evolution into the pre-chamber has been perturbed. Overall, RANS results show that the distributions of the turbulent kinetic energy and fuel concentration at spark-time agree well with the LES ensemble-averaged counterparts. This constitutes a prerequisite in view of the combustion phase and the accuracy reported provides further confidence in this regard.

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