EFFECT OF SOOT PARTICLE SIZE ON FOUR BALL METALLIC WEAR USING ELECTRON MICROSCOPY IMAGE ANALYSIS

Preechar Karin,Warawut Amornprapa,Park Watanawongskorn,Eakkawut Saenkhumvong,Chinda Charoenphonphanich,Katsunori Hanamura 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.3

The impact of soot primary nanoparticles affecting metal wear was investigated. The commercial Carbon Black (CB) with different primary particle sizes were mixed with the engine oil for simulating soot contamination. The physical properties of carbon black including density and hardness were calculated using Transmission Electron Microscopy (TEM) image analysis. The metallic wear test was evaluated by using a Four-ball wear tester. After the tests, the ball surfaces were inspected by utilizing High-Resolution Optical Microscope (OM), Scanning Electron Microscope (SEM) and Energy Dispersive X-ray spectroscopy (EDX) analysis. Based on a Four-ball wear test, the 1 % by weight of carbon black contamination shows a bit higher average wear scar diameter (WSD), but the surface roughness is reduced. SEM micrograph of metallic wear scar for the engine oil without soot shows the area of grooves, plastic deformation and subsurface crack. On the other hand, when carbon black is added to the oil, it can be seen that there are many deep grooves along with the sliding direction. The relationship of calculated oil film thickness, primary nanoparticle size distribution, carbon atom density of soot and hardness is clearly explained metallic wear mechanisms.

Oxidation Kinetics of Soot on Acicular Mullite Membrane Filter Using Electron Microscopy and Thermogravimetric Analysis

Saenkhumvong Eakkawut,Karin Preechar,Charoenphonphanich Chinda,Vittayakorn Naratip,Hanamura Katsunori 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.6

This paper investigates the oxidation kinetics of carbon black on acicular mullite using thermogravimetric (TGA) and mullite microstructures by scanning electron microscopy (SEM) for the development of diesel particulate filters (DPFs). It is observed that the amount of each chemical composition strongly affects the structure of mullite. The addition of AlF3 and V2O5 to mullite promotes the growth of needle-shaped mullite crystals. Thermogravimetric analysis was used to investigate and characterize chemical kinetics of soot oxidation for better understanding of designs and configurations of diesel particulate filters. The mass conversion of soot on the acicular mullite (ACM) is oxidized faster than that on the mullite (ML) membrane at all temperatures examined. The calculation of apparent activation energy (Ea) of soot oxidation with isothermal methods on mullite was presented. The results showed that activation energy of soot oxidation is enhanced with ACM than with ML at all temperatures examined. The average calculated apparent activation energy of soot oxidation on ACM and ML are 146.4 kJ/mole and 155.3 kJ/mole, respectively.

A Study on Curing Temperature and Fracture Mechanism of Carbon and Glass Fiber Reinforced Polymers Using an Electron Microscopy

Man Tial Cuai,Karin Preechar,Lin Ye Htet,Larpsuriyakul Patcharee,Ohtake Naoto 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.3

The morphology and nanostructure of carbon and glass fiber are investigated by using XRD, SEM and TEM analysis. The composites are divided into three groups which consists of “without post-curing”, “post-cured at 80 ºC for 6 hrs” and “post-cured at 120 ºC for 3 hrs” to investigate curing temperature effect. The mechanical properties of composites are tested in the indentation, tensile, and flexural machine with ASTM standard. According to the results, the hardness of post-curing of carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP) are increased approximately three-times and 5 % compared to with and without post-curing process. The tensile strength of CFRP and GFRP are approximately 458 MPa and 385 MPa, while post-cured at 120 ºC for the three-hour results are 490 MPa and 433 MPa respectively. In contrast, composites of treated fiber are not improved mechanical strength significantly for CFRP, while GFRP are slightly increased by 7 %. On the other hand, the flexural strength of treated carbon and glass fiber of composite are increased to 3 % and 15 % respectively. Higher temperature and treated fiber composites of carbon fiber are not significantly improved because high temperature curing and treated fiber created more porous to occur fracture internally.

PHYSICOMECHANICAL CHARACTERISTICS OF CARBON FIBER REINFORCED POLYMER COMPOSITE USING X-RAY DIFFRACTION, ATOMIC FORCE AND ELECTRON MICROSCOPIES

Ye Htet Lin,Preechar Karin,Patcharee Larpsuriyakul,Naoto Ohtake 한국자동차공학회 2022 International journal of automotive technology Vol.23 No.5

The physicomechanical characteristics of PAN-based carbon fibers were investigated by SEM-EDS, XRD, TEM and AFM analysis while the mechanical properties of the composites were studied by tensile, flexural and Charpy impact tests with ASTM standards. Regarding the tensile test of carbon fiber fabric, the average tensile strength of CF-Ⅰ, CF-II and CF-III fibers were around 147 MPa, 137 MPa and 225 MPa and the tensile modulus of those were 12.8 GPa, 13.2 GPa and 12.8 GPa, respectively. Later, the nanostructure of carbon fiber was recognized not as a pure graphite carbon structure because they mixed with graphite and amorphous structures. The higher tensile strength and modulus of CF-III fiber fabric was lower interlayer spacing (d002) because it consisted of more graphene layers in the graphite structure when compared with CF-Ⅰ and CF-Ⅱ fiber fabrics. Concerning AFM analysis’s results, CF-Ⅰ fiber fabric has higher surface roughness (Ra) of 34.8 nm and more in-depth with wider pit lines along the fiber axis, which caused higher mechanical properties among the three composites. According to this article, the nanostructure of carbon fibers had a lower impact on CFRP composite because the interfacial bonding between fiber and epoxy matrix, which obtained the higher mechanical properties in the composite, was directly enhanced by the higher surface roughness of the fibers.

Optical study on combustion characteristics of hydrotreated vegetable oil and blends under simulated CI engine conditions and various EGR

Vo Tan Chau,Charoenphonphanich Chinda,Karin Preechar,Susumu Sato,Hidenori Kosaka 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.9

Soot and NO x emissions are the inherent combustion characteristics of diesel engines. The modification of fuel property makes for an interesting study of methods for elimination of soot and NO x emissions. HVO and blends of 20 %, 50 %, 80 % by mass of HVO with commercial diesel fuel (mixed 7 % FAME), in combination with various EGR conditions were carried out to evaluate soot and NO xformation, as well as combustion characteristics of HVO blends in RCEM. The obtained results revealed that ignition delay, flame temperature, NO x and soot concentration decreased as HVO percentage increased. Mixing ratios of HVO with diesel showed a similar flame profile at baseline condition, higher flame temperature and darker soot density-KL regions were distributed on the upstream of spray flame. HVO displayed a slightly lower in-flame temperature and KL density, which led to a decrease of 33 % and 15.9 % of NO x and soot concentration, respectively, compared to diesel. By applying higher EGR levels, a reduction of heat release rate, flame temperature and NO x emissions were recorded. Also observed was an increase in ignition delay and soot concentration. Notably, soot at 10 % O 2concentration was lower than that of 15 % O 2 concentration.

INJECTION CHARACTERISTICS OF PALM METHYL ESTER BLENDED WITH DIESEL USING ZUECH’S CHAMBER

Prathan Srichai,Pop-Paul Ewphun,Chinda Charoenphonphanich,Preechar Karin,Manida Tongroon,Nuwong Chollacoop 한국자동차공학회 2018 International journal of automotive technology Vol.19 No.3

This research attempts to characterize the injection of palm biodiesel blended with diesel in a Zuech’s chamber. Thailand conventional diesel (mandated blend of biodiesel at 5 % or B5), palm biodiesel (B100) and four other biodiesel blends ratios (B20, B40, B60 and B80) were investigated with single hole injector of 140 and 200 μm diameters, injection pressure of 40 MPa to 160 MPa, constant back pressure of 4.5 MPa and energize time of 2.5 ms. The results show that increasing biodiesel blending ratios leads to longer injection delay, larger injection pressure drop, smaller injection quantity discharge coefficient (Cd) and shorter injection duration. With increasing biodiesel blending ratio, high Cavitation number from biodiesel viscosity decreases Reynolds number. Increasing injector diameter from 140 μm to 200 μm has reduced injection delay, increased fuel injection quantity, discharge coefficient and remaining injection duration. The increasing of injection pressure were improve, injection delay, injection duration, injection quantity and discharge coefficient until injection pressure 120 MPa. In addition at injection pressure over 120 MPa are decrease injection quantity and discharge coefficient, it effect form the cavitation phenomena. Increasing of viscosity, density, Bulk modulus and sound velocity were effect to increase injection delay, with reduce injection quantity, injection duration and pressure drop during injection process.

COMBUSTION CHARACTERISTICS OF HYDROTREATED VEGETABLE OIL-DIESEL BLENDS UNDER EGR AND LOW TEMPERATURE COMBUSTION CONDITIONS

Sombat Marasri,Pop-Paul Ewphun,Prathan Srichai,Chinda Charoenphonphanich,Preechar Karin,Manida Tongroon,Hidenori Kosaka 한국자동차공학회 2019 International journal of automotive technology Vol.20 No.3

This paper investigates the effects of Hydrotreated vegetable oil (HVO)-diesel blends on combustion characteristics under various ambient oxygen concentrations and ambient temperatures in a constant volume combustion chamber (CVCC). Combustion characteristics were presented in terms of heat release rate, ignition delay and integral heat release. The shadowgraph images of spray combustion were presented for spray development and combustion progress. The experiment was carried out on CVCC under constant injection pressure and energizing time. The synthetic gas with varied oxygen concentrations between three discrete values from 21, 15 and 10 % to simulate EGR on engine conditions. The ambient temperatures were varied at 1100, 900 and 700 K to study the effects of ambient temperatures. Four different fuels were tested: commercial diesel, commercial diesel-HVO blends and HVO with the single-hole injector. The results showed that decreasing ambient oxygen concentration to 10 % resulted in 13.42 % lower heat release rate and 13.89 % lower integral heat release. This also extended ignition delay. Decreasing ambient temperature resulted in longer ignition delay with higher peak heat release rate. Increasing HVO showed 6.43 % shorter ignition delay compare to diesel due to higher cetane number. The shadowgraph images showed that HVO has better evaporation 0.7 to 0.9 ms after injection due to its lower density, viscosity and distillation temperature at T90.