Numerical Investigation of Steady Natural Convection from a Heated Cylinder Enclosed in Inclined Square Enclosure
Kumar D., Kumar C., Gupta A.K., Baranwal A.K.
Book chapter, Springer Proceedings in Materials, 2025, DOI Link
View abstract ⏷
This study explains the result of natural steady convection that originates from a heated cylinder within an inclined enclosure. The convection processes occurring due to the temperature differences among the heated cylinder, heated walls, and the cold walls of the enclosure were investigated using different dimensionless numbers (Grashof and Prandtl numbers). The Grashof and Prandtl numbers span from 10 to 104 and 0.7 to 90 respectively. A numerical solution to the governing partial differential equations was obtained. The intricate flow patterns visibly represented by the streamlined contours when Prandtl and Grashof numbers were applied. Convection currents could be found around the heated inner cylinder, demonstrating how buoyancy-driven forces played a pivotal role in shaping the circulation in the annular space. Isotherm contours illustrate thermal gradients and the impact of buoyancy-induced flow. The local Nusselt number distribution can be used to determine the various contributions made by dimensionless numbers to the heat transfer rate. Data are often displayed using variations in the average Nusselt values on the cylinder surface. The local Nusselt number was used to find out how much convective heat transfer occurred at a specific location on a surface compared to conductive heat transfer. Heat transfer outcomes can now be predicted in a new application because they have been observed as a function of Grashof and Prandtl numbers.
Applications and formulation of bio-ink in the development of tissue scaffold: A review
Book chapter, Bioimplants Manufacturing: Fundamentals and Advances, 2024, DOI Link
View abstract ⏷
Three-dimensional (3D) bioprinting technology enables the fabrication of porous structures with complicated and variable geometries, allowing for the equitable distribution of cells and the regulated release of signalling components, which distinguishes it from traditional tissue scaffolding approaches. In 3D bioprinting, various cell-laden materials, including organic and synthetic polymers, have been used to create scaffolding systems and extracellular matrix (ECM) for tissue engineering (TE). However, significant technological hurdles remain, including bio-ink composition, printability, customizing mechanical and biological characteristics in hydrogel implants, and cell behaviour guiding in biomaterials. This chapter investigates several methodologies for hydrogel-based bio-inks that can mimic the ECM environment of real bone tissue. The study also looks at the process factors of bio-ink formulations and printing, as well as the structural requirements and production methods of long-lasting hydrogel scaffolds. Finally, contemporary bioprinting techniques are discussed, and the chapter concludes with an overview of the existing obstacles and probable future prospects for smart hydrogel-based bio-inks/scaffolds in tissue regeneration.
Retention Problem Free High Density 4T SRAM cell with Adaptive Body Bias in 18nm FD-SOI
Kumar C., Kumar R., Grove A., Chatterjee S., Dhori K.J., Rawat H.
Conference paper, Proceedings - 2022 35th International Conference on VLSI Design, VLSID 2022 - held concurrently with 2022 21st International Conference on Embedded Systems, ES 2022, 2022, DOI Link
View abstract ⏷
Area scaling of 6T SRAM cells has stagnated in advanced technology nodes [1]. The conventional 6T SRAM bitcell is bulky because of two pull-down NMOSs, which are sized to ensure cell stability. In this work, we present alternative 4T SRAM and 6T SRAM cells that eliminate these pull-down transistors. A 4T SRAM cell, so designed, is 10-13% denser than a 6T bitcell. 4T SRAM cells typically suffer from low data retention time and need to be refreshed regularly. We apply Adaptive Body Bias to alleviate the retention problem. In 18nm FD-SOI technology, the retention problem is completely mitigated, and leakage is reduced by 6× times that of 6T SRAM cells.
Design and fabrication of three direction dumping mechanism in trucks
Sharma S.L., Agrawal A.P., Kumar C.
Conference paper, Materials Today: Proceedings, 2022, DOI Link
View abstract ⏷
This study aims to overcome difficulties in loading and unloading material in a single dumping mechanism in industries. The delivery of material is not a difficult task in recreational areas but in certain places where space is less for the trailer to deliver, which could be difficult for the truck driver. To control the difficulty of the truck pilot, an initiative of designing and fabricating three directional discarding mechanism in trucks can deliver the material in three directions such as in the left, right, and as a usual rear region. A hydraulic pneumatic cylinder is mounted in the damming mechanism system to lift the trolley in a particular direction & position. For tilting the trolley wagon in identified direction, locking pins in the trolley wagon are hardened to lock. This paper mainly focuses on the fabrication with design calculations of locking mechanisms controlled by directional control. This mechanism saves energy and time to load and unload material without difficulties.
Fiber laser welding of Ti-6Al-4V alloy
Kumar C., Paul C.P., Das M., Bindra K.S.
Book chapter, Advanced Welding and Deforming, 2021, DOI Link
View abstract ⏷
In the present chapter, the fundamentals of laser beam welding technologies are discussed in detail. The basic principle of laser generation, behavior, and characteristics of a laser beam are elucidated. The working principles of fiber laser, their construction, and advantages over other lasers are explored. Also, various welding process parameters which affect the quality of weldments are discussed. The titanium alloys possess an outstanding combination of lightweight, moderate corrosion resistance, and high specific strength. However, it becomes highly reactive beyond 300°C temperature. Therefore, the weldability aspects of Ti-6Al-4V are also discussed. The need for the design and fabrication of a shielding gas delivery system in laser welding of Ti-6Al-4V alloy is explored. The mechanism of phase transformation in the fusion zone is discussed briefly. The dependencies of various kinds of weld bead features on process parameters, a microstructural study in fusion and heat-affected zones, mechanical properties such as hardness, tensile properties, and different types of weld bead defects are discussed. The modes of fracture failure during tensile testing of fiber laser weldments of Ti-6Al-4V material are discussed. Also, it explores the prospects of the development of laser welding set-up in the future by considering their cost, beam quality, portability, and robust design.
Recovery of carbon rich material:-Recycling of spent pot lining: A review
Agrawal A., Kumar C., Meshram A.
Conference paper, Materials Today: Proceedings, 2021, DOI Link
View abstract ⏷
Spent pot lining (SPL) is a carbon rich material generated during primary aluminium smelting process. The major constituents of SPL are carbon (40-50%), fluoride (10-18%), aluminium (10-13%), cyanide (700-4500ppm) and sodium (12-16%) along with other metals like calcium, iron, lithium, titanium and magnesium in trace amounts. SPL ends up getting landfilled but the hazardous composition of the waste (presence of fluoride and cyanide), coupled with toxicity and reactivity with water, harm the environment. Gases like methane, ammonia and hydrogen cyanide evolve when SPL is exposed to water. Water and soil resources are hampered due to the SPL landfilling. This review focuses on the recovery of carbon and fluoride for its utilization as fuel in cement industry and as a carbonaceous material in iron making industry. The article describes hydrometallurgical extraction processes from different grades of SPL in which cyanide is extracted in water washing stage whereas fluoride is recovered as CaF2. The acid leaching (by sulphuric acid, perchloric acid, hydrofluoric acid and hydrofluorosilicic acid) removes the rest of the fluorides, silicates, cryolite, alumina and aluminium fluoride. Final treated SPL is used as reducing agent in iron making industry. SPL has high mechanical strength against breakage, abrasion and compression. Due to these features it can be used as granulated material in reduction reactors. This review article discusses the composition of different grades of SPL, the environmental impacts, methods for recovery of carbon, corundum, cyanides and fluorides and its applications in iron making and cement industry in economical and environment friendly manner.
Exploration of Parametric Effect on Fiber Laser Weldments of SS-316L by Response Surface Method
Article, Journal of Materials Engineering and Performance, 2021, DOI Link
View abstract ⏷
Fiber laser welding experiments are conducted on SS316L austenitic stainless steel plates based on the statistical design of experiments technique. A special kind of fixture is designed and fabricated with a facility to provide argon gas and is made up for bead protection. The influence of beam power, welding speed, and defocused position on fusion zone width, fusion zone area, and tensile strength of weldments is studied and discussed briefly. The most influencing factors and their percentage contribution on output responses are identified by analysis of variance technique. Beam power directly influences the bead features, whereas welding speed inversely affects it. However, the defocused position shows an insignificant effect on the fusion zone area within the selected range. The tensile strength increases with an increase in both beam power and welding speed up to a particular optimum value, and beyond that, it starts reducing. The highest hardness value is observed in the fusion zone at ‘1’ mm defocused position below the workpiece surface due to a decrease in grain size and interdendritic spacing. Ductile mode of fracture failure is found in both base material and weldment. The optimum welding condition obtained in this study yields full penetration, narrower weld width, lesser fusion zone area, minimal weld defects, and acceptable tensile strength of weldments.
Microstructural Characterization of Ti-6Al-4V Alloy Fiber Laser Weldments
Conference paper, Lecture Notes in Mechanical Engineering, 2020, DOI Link
View abstract ⏷
The quality of fiber laser welded specimens of Ti-6Al-4V alloy plates in butt joint is examined. A special kind of fixture is designed and fabricated for providing shielding gas. The microstructural analysis at various positions within heat-affected zone and in fusion zone are explored and its microstructural morphologies are compared. Due to the chronological distribution of temperature gradient, a nonhomogeneous microstructure is developed from fusion zone to base metal zone. Various kinds of microstructural morphology of martensitic structure, i.e., α′ martensite, massive α (αm), and blocky α are found in fusion zone. Also, the variations in amount of α′ martensite are found inside heat-affected zones. Maximum hardness is obtained in fusion zone due to the occurrence of higher quantity of α′ martensitic structure.
Experimental Study of Fiber Laser Weldments of 5 mm Thick Ti–6Al–4V Alloy
Kumar C., Das M., Paul C.P., Singh B.
Book chapter, Lecture Notes on Multidisciplinary Industrial Engineering, 2019, DOI Link
View abstract ⏷
Titanium and its alloys are known as a workhorse for aerospace and automobile industries. These alloys possess several features like high strength, better corrosion resistance, lower density, and very good biocompatibility. It is extensively used in chemical, aviation, aerospace, medicinal, and automotive industries. In this study, an experimental investigation and metallurgical characterization of fiber laser weldments of 5 mm thick Ti–6Al–4V alloy plate are performed. After experiments, the qualities of the welded specimens are investigated in terms of penetration depth, weld appearance, bead geometry, hardness, and developed microstructures in fusion and heat-affected zones. The energy dispersive X-ray spectroscopy analysis confirms shielding gas effectiveness. The microstructures in fusion zone, as well as heat affected zones, are suitably controlled by welding process parameters. The Vickers microhardness of the welded specimens highly depends on developed microstructures in the fusion and heat-affected zones. The results show that the beam power in laser welding process plays a major role for full penetration in the base plate. There is a critical range of welding power that produces full penetration, narrow weld width, small HAZ, and aesthetic bead appearance with satisfactory bead hardening.
Weld Quality Assessment in Fiber Laser Weldments of Ti-6Al-4V Alloy
Kumar C., Das M., Paul C.P., Bindra K.S.
Article, Journal of Materials Engineering and Performance, 2019, DOI Link
View abstract ⏷
Laser welding experiments are performed on Ti-6Al-4V alloy sheets by adopting fiber laser. A special kind of workpiece fixture is designed and fabricated for providing shielding gas. After experiments, penetration depth, fusion zone width and heat-affected zone size at different locations within weld bead are measured and discussed in detail. Influence of line energies on the formation of non-uniform microstructure within weld bead is explored by conducting microstructural analysis. Various kinds of microstructural morphology of martensitic structure such as α′ martensite, blocky α, massive α and basket-weave microstructure are found in fusion zone. Experimentally, it is found that beam power is the key parameter for controlling penetration depth. Higher hardness is noticed within fusion zone due to the existence of large volume of α′ martensite. Tensile strength and hardness of welded specimens are increased with decreasing line energy. Small amount of micropores are also found in solidified weld bead. However, its sizes are in acceptable range as per BSEN:4678 standard. Most favorable welding condition is identified as a combination of beam power of 800 W and welding speed of 1000 mm/min which yields full penetration, narrower bead width, small heat-affected zone, minimal defects and acceptable mechanical properties.
Fabrication and characterization of weldments AISI 304 and AISI 316 Used in industrial applications
Kant R., Mittal R., Kumar C., Rana B.S., Kumar M., Kumar R.
Conference paper, Materials Today: Proceedings, 2018, DOI Link
View abstract ⏷
Gas tungsten arc welding (GTAW) and Shield metal arc welding (SMAW) are processed by using E347-16 electrode and filler wire to prepare the dissimilar weldments. The aim of study was to measure the effect of welding parameters: current, voltage, gas flow rate, nozzle to plate distance on tensile strength (TS), grain structure and hardness. The arc voltage and welding current was selected as 40,60 and 80V and 30,45 and 60amp respectively. The welding speed was selected as 4, 8, 12cm/sec. There is zero cracks, porosity, blow holes, spatter found in welding process of plate no. 2(AISI 304 &AISI 316 with ER-309L) using non consumable tungsten electrode with argon gas and also the microstructure study shows that the welding is self cooled welding structure with fine austenitic structure and very little heat affected zone found in this process. TIG welded dissimilar joint has best joint strength, uniform hardness variation as well as joint integrity.
Estimation of creep parameters of rock salt from uniaxial compression tests
Singh A., Kumar C., Kannan L.G., Rao K.S., Ayothiraman R.
Article, International Journal of Rock Mechanics and Mining Sciences, 2018, DOI Link
View abstract ⏷
This paper discusses an approach to predict the creep behaviour of rock salt using uniaxial compression testing machine, as the conventional creep testing equipments are expensive and scarcely available. As commonly observed in brittle rock, a distinct Kaiser effect is not found during pre-peak loading path, but after unloading a distinct Kaiser effect is observed in rock salt. In the present study, Acoustic Emissions (AE) technique is used to infer the rock salt behaviour under uniaxial compression. The AE technique used in the present study to explain the rock salt behaviour is based on a combination of Maxwell and Hooke models. Using these models, elastic and viscous parameters are calculated. The proposed model is able to predict the stress-strain response of rock salt with a fair accuracy in both loading and unloading conditions. It is observed that the viscosity has negative correlation with the strain rate and hence the calculated viscous parameters are then extrapolated. The extrapolated results of viscosity for different strain rate in the range of 10− 6.5–10− 10 s- 1 are very close with reported values from the literature and for the strain rate below 10− 10 s-1, the predictions are higher than the values reported in literature. This is due the fact that below 10− 12 s-1 strain rate, the viscosity becomes independent of the strain rate and its value becomes almost constant for 3–5 mm grain size rock salt. Hence a cutoff viscosity is proposed at a value of 1018 Pa.sec.
Comparison of bead shape, microstructure and mechanical properties of fiber laser beam welding of 2 mm thick plates of Ti-6Al-4V alloy
Kumar C., Das M., Paul C.P., Bindra K.S.
Article, Optics and Laser Technology, 2018, DOI Link
View abstract ⏷
Fiber laser beam welding experiments are carried out on 2 mm thick plates of Ti-6Al-4V alloy at various welding conditions. A specially designed workpiece fixture with shielding gas delivery system is fabricated and effectiveness of shielding gas is confirmed by energy dispersive X-ray spectroscopy analysis. Two different types of bead cross-sections i.e. T-shaped and nearly X-shaped beads are observed at different line energies. After experiments, width and area of fusion zone and size of heat affected zone are measured and further analyzed. The microstructural studies at different locations in heat affected zone and also in fusion zone are carried out with optical microscope and their morphologies are compared at different welding conditions using field emission scanning electron microscope. The porosities are observed in both T and X-shaped weld beads at different line energies. However, their sizes are in acceptable range as per BS EN:4678 standard. The maximum microhardness is found in fusion zone due to the presence of large amount of α′ martensite. The line energy utilization factor is higher for T-shaped bead than X-shaped bead. The tensile strength of T-shaped bead is lower than X-shaped bead due to higher non-uniformity in the distribution of plastic strain. The experimental results show that T-shaped welding conditions are favorable while considering full penetration in keyhole mode, narrower weld width and lesser heat affected zone.
Engineering properties of rock salt and simplified closed-form deformation solution for circular opening in rock salt under the true triaxial stress state
Singh A., Kumar C., Gopi Kannan L., Seshagiri Rao K., Ayothiraman R.
Article, Engineering Geology, 2018, DOI Link
View abstract ⏷
Underground structures and storage caverns are increasingly being constructed in rock salt due to its unique self-healing ability and impervious nature. Rock salts are likely to experience and develop time-dependent behavior/deformation. Hence, the characterization of rock salt for its properties, including viscosity, are pertinent for design of these structures. In addition, the material in underground openings experiences true-triaxial stresses and hence it is vital to study the behaviour of such structures under true-triaxial loading conditions. This paper presents results of extensive laboratory testing carried out on specimens of Khewra rock salt for its physico-mechanical properties. Physical and engineering properties such as mineralogy, density, sonic wave velocity, resistivity, point load index and shear strength properties were measured. A simplified closed-form solution which deploys three-dimensional strength criterion (Mogi-Coulomb) with Maxwell viscoelastic behaviour is developed to assess the stress and deformation behaviour of circular opening in plane strain condition. The closed-form solution assumes that the material exhibits the Maxwell behavior when the stresses are lower than the yield stress and the material behavior is the combination of Maxwell and Mogi-Coulomb elastoplastic material, when the stresses are equal to the yield stress. In addition, a cylindrical wellbore problem is solved with the proposed closed-form solution and the deformation of the wellbore was estimated for the different time intervals.
Characteristics of fiber laser weldments of two phases (α+β) titanium alloy
Kumar C., Das M., Paul C.P., Bindra K.S.
Article, Journal of Manufacturing Processes, 2018, DOI Link
View abstract ⏷
Laser welding experiments are conducted at various welding conditions on Ti-6Al-4 V alloy plates by employing fiber laser. A special type of workpiece fixture having provision of supplying shielding gas is fabricated for the protection of weld bead efficiently from environmental contamination. The influence of process parameters i.e. welding speed on the development of non-homogeneous microstructure of the weld bead is investigated by conducting microstructural characterization in details. Different morphologies of martensitic phase such as α´martensite, massive αm, blocky α and basket-weave structure are observed in the fusion zone. The variation in amount of α´ martensite is observed within heat affected zone. The calculated cooling rate and microstructure evaluation in the fusion zone are consistent with the continuous cooling transformation curve of Ti-6Al-4 V alloy. Higher hardness is found in fusion zone of the weldments. At lower welding speeds (500 ̶ 600 mm/min), underfill weld defects and at higher welding speed (800 mm/min) the micro-pores are observed in the weld bead. However, sizes of micro-pores are within the acceptable range as per BSEN: 4678 European standard. The microhardness and tensile strength of weldments are increased with increasing welding speed due to the development of finer α´ martensite in the fusion zone. For a fixed beam power of 1200 W, the most favorable range of welding speed (700 ̶ 800 mm/min) is identified which produced consistently high quality welds without crack and acceptable pore size. Vickers microhardness and tensile test results indicate that the optimal process parameters obtained in the current study can be suitably used in industries.
Rheological Behaviour of Rock Salt under Uniaxial Compression
Singh A., Kumar C., Kannan L.G., Rao K.S., Ayothiraman R.
Conference paper, Procedia Engineering, 2017, DOI Link
View abstract ⏷
Rock salt is considered as the most suitable material for underground storage of hydrocarbons as well as the disposal sites for hazardous waste in view of its unique physical and mechanical behaviour. In India, rock salt reserves are spread sub-surface over an area of more than 50,000 sq.km. covering much of north-western region of Rajasthan. So far, limited studies on the physical and mechanical properties of rock salt in this region have been carried out. This paper discusses the behaviour of rock salt under uniaxial compression (UCS) measured from the samples collected in-situ. As reported in literature that the rock salt is likely to exhibit highly viscous behaviour, and therefore there is a need for understanding rheological behaviour of rock salt through a theoretical model. In the present study, a rheological model is proposed for predicting the stress-strain behaviour of Indian rock salt under UCS condition. Predicted stress-strain curve from the proposed rheological model using MATLAB is compared with the experimentally measured stress-strain curve. Comparison of the both experimental and predicted results indicates that proposed rheological model is able to predict stress-strain behaviour of rock salt under UCS condition. The results show that rock salt exhibits distinct time-dependent viscous behaviour and deformations.
Experimental investigation and metallographic characterization of fiber laser beam welding of Ti-6Al-4V alloy using response surface method
Kumar C., Das M., Paul C.P., Singh B.
Article, Optics and Lasers in Engineering, 2017, DOI Link
View abstract ⏷
In the present study, experimental investigations of fiber-laser-beam-welding of 5 mm thick Ti-6Al-4V alloy are carried out based on statistical design of experiments. The relationship between the process parameters such as welding power, welding speed, and defocused position of the laser beam with the output responses such as width of the fusion zone, size of the heat affected zone, and fusion zone area are established in terms of regression models. Also, the most significant process parameters and their optimum ranges are identified and their percentage contributions on output responses are calculated. It is observed that welding power and speed plays the major role for full penetration welding. Also, welding power shows direct effect whereas welding speed shows the inverse effect on the output responses. The bead geometry is influenced by the defocused position of the laser beam due to the change in power density on the workpiece surface. However, overall fusion zone area is unaffected. Mechanical characterization of the welded samples such as microstructural analysis, hardness, and tensile tests are conducted. It is noticed that the hardness value of the FZ is higher than the HAZ and BM zone due to the difference in cooling rate during welding which promotes the formation of α′ martensitic phase in the FZ. Also, an average hardness value in the FZ is compared for two different defocusing positions (i.e. 1 and 2 mm). It is found that hardness value is higher for 1 mm defocused position than 2 mm due the decrement in grain size below a critical range at 2 mm defocused position. The ultimate tensile strength and % elongation of the welded samples are degraded as compared to BM which can be further improved by post heat treatment.
A 3-D Finite Element Analysis of Transient Temperature Profile of Laser Welded Ti-6Al-4V Alloy
Kumar C., Das M., Biswas P.
Book chapter, Topics in Mining, Metallurgy and Materials Engineering, 2015, DOI Link
View abstract ⏷
In this work, a numerical investigation of transient temperature profile of Laser beam welding process is carried out. A 3-D finite element modelling is developed considering combined double-ellipsoidal heat source model for both spot and moving heat sources. The temperature dependent thermo-physical material properties of Ti-6Al-4V alloy are incorporated. The effect of latent heat of fusion and convective and radiative boundary conditions are considered. The effect of laser beam power on the transient temperature profile and the dimensions of the heat affected zone are analysed. From finite element simulation, it is observed that the peak temperature in the fusion zone increases with increased laser beam power. Also, the size of the heat affected zone strongly depends on the power of the laser beam.
Reply to the discussion on “Evaluation of selected equations for predicting scour at downstream of ski-jump spillway using laboratory and field data” [Engineering Geology 129-130 (2012) 98-103]
Note, Engineering Geology, 2013, DOI Link
Reply to the Comments on “Evaluation of selected equations for predicting scour at downstream of ski-jump spillway using laboratory and field data” by Chandan Kumar, P. Sreeja [Engineering Geology 129-130 (2012) 98-103]
Note, Engineering Geology, 2013, DOI Link
Evaluation of selected equations for predicting scour at downstream of ski-jump spillway using laboratory and field data
Article, Engineering Geology, 2012, DOI Link
View abstract ⏷
The provision of spillways in the structure of a dam enables proper disposal of flood water in excess of the reservoir capacity, and regulates the energy of flowing water downstream. Some spillways dissipate energy in the form of ski-jump which leads to scouring process. Scour holes formed downstream of spillways may affect the safety and stability of the structure. Therefore accurate prediction of the scour depth is necessary to ensure the safety of dam as well as its abutments. The prediction procedure is extremely complex due to various hydraulic and geological factors influencing scouring phenomenon. Several researchers have developed empirical equations for scour depth predictions, keeping in view the above mentioned factors. It is noted from the literature that there are not many studies to evaluate the efficiency of these equations for scour depth prediction. Therefore, the present study attempts to evaluate different empirical equations available in the literature for scour depth prediction using experimental and field data reported in the literature. For this purpose, a database has been formulated based on the scour depth values reported in the literature. © 2012 Elsevier B.V..
Effects of ethanol addition on performance, emission and combustion of di diesel engine running at different injection pressures
Kumar C., Athawe M., Aghav Y.V., Gajendra Babu M.K., Das L.M.
Conference paper, SAE Technical Papers, 2007, DOI Link
View abstract ⏷
Ethanol is an alternative renewable fuel produced from various agricultural products. Ethanol-diesel emulsion technique is used for the utilization of ethanol in diesel engines wherein ethanol is used without any modification. The performance, combustion and emission characteristics of a direct injection (DI) diesel engine for off-highway application were evaluated using ethanol-diesel microemulsions. The addition of ethanol to diesel fuel simultaneously decreases calorific value, kinematic viscosity and stability of fuel. Ethyl acetate was used as an additive/ingredient to keep the blends in homogeneous and stable state. Blends (D80/E13/EA07; D70/E17/EA13; D60/E23/EA17) were selected for engine experiments based on stability behavior and fuel properties. The results showed no significant power reduction in the engine operation with ethanol-diesel microemulsions. Although, brake specific fuel consumption (BSFC) increased, improvement was observed in the brake specific energy consumption (BSEC). The thermal efficiency also improved significantly at lower loads. NOx and smoke emissions were reduced by 5-10% and 15-50%, respectively. UBHC and CO deteriorated especially at lower loads but improved at higher loads. From the combustion analysis, it was observed that the use of ethanol blended diesel fuel prolonged the ignition delay along with shortening of total combustion duration. Studies conducted at different injection pressures (200, 250, 300 and 350 bar) on different loading conditions showed that the higher injection pressure reduces CO and smoke emissions with respect to diesel fuel. Copyright © 2007 SAE International.
Experimental investigations on a karanja oil methyl ester fueled DI diesel engine
Kumar C., Gajendra Babu M.K., Das L.M.
Conference paper, SAE Technical Papers, 2006, DOI Link
View abstract ⏷
The methyl ester of karanja oil, known as biodiesel, is receiving increasing attention as an alternative fuel for diesel engine. This paper presents the results of investigations carried out in studying the fuel properties of karanja oil methyl ester (KOME) and its blend with diesel from 20% to 80% by volume and in running a DI diesel engine with these fuels. Engine tests have been carried out with the aim of obtaining performance characteristics such as Brake specific fuel consumption(BSFC), brake thermal efficiency, brake power, exhaust gas temperature, emission such as CO, UBHC, NOx, smoke opacity and combustion parameters to evaluate and compute the behavior of the diesel engine running on KOME and its blends with diesel fuel. The addition of KOME to diesel fuel has significantly reduced CO, UBHC and smoke emissions but it increases the NOx emission slightly. The results show that: no significant power reduction in the engine operation when operated with blends of KOME and diesel fuel. Although there is a slight increase in brake specific fuel consumption (BSFC), brake specific energy consumption (BSEC) has improved. The brake thermal efficiency also improved remarkably at B20 and B40. Copyright © 2006 SAE International.
Exhaust emission characteristics of a constant speed SI engine on denatured anhydrous and aqueous ethanol of different proofs
Bhattacharya T.K., Kumar C., Mishra T.N.
Article, Journal of the Institution of Engineers (India): Chemical Engineering Division, 2005,
View abstract ⏷
Denatured anhydrous and aqueous ethanol of 200°, 190°, 180°and 170° proof has been burnt in a constant speed SI engine designed to operate on kerosene. The effect of water content in the fuel on engine exhaust emissions has been studied. The emission of carbon monoxide is found to be 14.0%-23.7% lower and a decrease in unburnt hydrocarbon emission from 99% to 29% is observed on denatured ethanol of different proofs as compared to that observed on kerosene. The emission of NOx is found to be higher on denatured ethanol of different proofs. However, it is comparable with kerosene when engine is operated on 170° proof ethanol.
