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ThesisItem Open Access Parametric optimization of activated-TIG welding of hot rolled steel (IS 5986) using taguchi method(G. B. Pant University of Agriculture and Technology, Pantnagar, 2022-10) Rawat, Bharat V.P.S.; Jadoun, R. S.The present investigation aims to optimized & develop input parameters for joining of Hot rolled steel using activated tungsten inert gas (A-TIG) welding process. Three combinations of fluxes were prepared to decide suitable flux for Hot rolled steel. The design of experiment was carried out for optimization of welding parameters to achieve the desired depth of penetration. The square butt weld joints were fabricated on 8 mm thick plates employing A-TIG welding using developed flux and optimized process parameters employing single side welding procedure. The Ultimate Tensile testing hardness test and impact tests were carried out on the base metal and weld joint. The strengths, ductility and impact toughness of the joints were found to be comparable with that of the base metal. Gas Tungsten Arc Welding (GTAW), also called Tungsten Inert Gas welding (TIG) is one of the main welding methods which have been widely used in industries for the welding of stainless steel, titanium alloy, and other nonferrous metals for its high weld quality and lower equipment Investment. The major limitation of TIG welding of steel is mainly the limited thickness of material which can be welded in a single pass and that has a lower production rate. Therefore, enhancements in the depth of penetration in weld bead have long been sought in steel weldments produced by TIG welding process. These limitations have been overcome by introducing oxide powders at the joint during the TIG welding process which is called Activated Tungsten Inert Gas Welding (A-TIG). Hot rolled steel is used in a range of automobile products it has excellent forming and welding characteristics. Post-weld annealing is not required when welding thin sections. It has excellent corrosion resistance in a wide range of atmospheric environments and many corrosive media. In the present work, TIG Welding was carried out on Hot Rolled steel plates of 8 mm thickness. In the first phase, the specimens were welded as bead on plate. The Taguchi method is the technique is used to determine the level of influence of the independent variables on the dependent variables. The independent variables have been taken for this study are 5 of welding parameters,viz three different types of flux composition combination of two compound TiO2 And SiO2 flux, three set of welding voltage, welding current, gas flow rate, root gap is used. The dependent variables are tensile strength (TS), Hardness (HR), Impact strength (IS), Depth of Penetration (DP), Bead Width (BW), of the weld morphology are used. The SEM images of the macro structures of weld morphology were compared. The results obtained from the macro structures of weld morphology indicated that the higher depth of penetration has been achieved in the specimens welded with A-TIG welding process when compared with Conventional TIG welding process. The results obtained from the Taguchi, L27 O.A. technique indicated that the activating flux showed the maximum percentage of contribution in weld morphology. In Next phase of this study was to determine the influence of two component fluxes on the weld morphology of A-TIG weldments of Hot Rolled steel plates. The activating fluxes such as TiO2 & SiO2, were applied with different proportions to the specimens. Experimental results indicated that using 60% TiO2 +40% SiO2 flux combination leads to a significant increase in joint penetration and the aspect ratio.ThesisItem Open Access Experimental investigation of thermo- hydraulic performance of rotating packed bed using air-water System(G. B. Pant University of Agriculture and Technology, Pantnagar, 2022-04) Sandeep Kumar; Murthy, D. S.Rotating packed bed (RPB) has a great potential for process intensification in thermal systems. However, the available literature is only focused on its mass transfer aspects and no study shows its heat transfer aspects. In rotating packed bed, the water flows outwards from the inner eriphery of a rotating rotor by centrifugal action and air travels inwards from the outer periphery by imposed pressure gradient making a counter current interaction with each other. The rotation of the rotor gives control over the water distribution unlike in conventional columns where gravity is the only driving force. In present work, rotating packed bed (RPB) have been explored for process intensification in thermal systems using air-water as working fluids. The thermo-hydraulic performance of rotating packed was carried out considering the air flow rate range varying from 0.007625 kg/s to 0.020175 kg/s, water flow rate varies from 0.033 kg/s to 0.133 kg/s and rotational speed considered is 0-2000 rpm. The thermal performance parameters such as cooling range, approach, water evaporation rate, heat transfer rate, Merkel number, and effectiveness for the RBP were experimentally evaluated for the given airflow rate, water flow rate and water inlet temperature (35, 40, and 45°C) and rotational speed. The optimum result for all the thermal performance parameters was observed at 1200 rpm. At the optimum condition, the observed value of cooling range was 15 ̊C, the value of approach was 12.2 ̊C, water evaporation rate was 0.000904 kg/s, effectiveness was 0.49 and the Merkel number was 0.426. The results were found to be in agreement with CTI (Cooling Technology Institute) performance curve charts, confirming the feasibility of RPBs to be used as thermal systems.ThesisItem Open Access Fabrication and evaluation of nanobentonite/epoxy laminated poplar veneer lumbers(G. B. Pant University of Agriculture and Technology, Pantnagar, 2021-07) Mohd Arif; Misra, AnadiA method of modification of poplar wood veneers (PWVs) was developed through adhesive bonding with bentonite epoxy nanocomposites (BENs).The process of adhesive bonding was executed through alternate laying of BENs across 4- layers of PWVs by pressing at 10kg/cm2 over 24h.This has afforded laminated veneer lumbers (LVLs) with improve mechanical properties, thermal and dimensional stability. LVLs were characterized through Fourier transformed infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. Effect of weight fraction (WF, wt%) of nanobentonite (NB) ranging 0 to 3.0 on mechanical properties, thermal and dimensional stability of LVLs was investigated with reference to PWVs as control. With WF of NB, the LVLs have rendered ultimate modification (%) in their flexural (80.49), tensile (63.81) and impact strength (18.35) at 2.0 WF of NB over PWVs. LVLs at 12 mm thickness with 2 WF of NB has rendered water resistance by 48.97% and thickness swelling (27.46%) over PWVs. Simultaneous thermogravimetric-differential thermal analysis (TG-DTA-DTG) reveals reduction in moisture content of LVLs ranging 4.92 to 1.4 with WF of NB. TG-DTA reveals onset temperature of degradation of LVLs at 200o C with marginal reduction in their heat of fusion over PVWs. DTG reveals thermal degradation (mg/min) of LVLs ranging 0.79 to 0.41 in the temperature range of 287.93 to 294.40oC. TG endset of LVLs was commenced in the temperature range of 485.78 to 600.68o C with heat of fusion (J/mg) ranging 49.5 to 50.8 and average char residue of 3.45% .The present study reveals sustainable modification of PWVs thorough adhesive boding with BENs to deliver the LVLs with improved durability, thermal and dimensional stability.ThesisItem Open Access Fabrication and evaluation of nanobentonite/epoxy laminated poplar veneer lumbers(G.B. Pant University of Agriculture and Technology, Pantnagar, District Udham Singh Nagar, Uttarakhand. PIN - 263145, 2021-07) Mohd Arif; Misra, AnadiA method of modification of poplar wood veneers (PWVs) was developed through adhesive bonding with bentonite epoxy nanocomposites (BENs).The process of adhesive bonding was executed through alternate laying of BENs across 4- layers of PWVs by pressing at 10kg/cm2 over 24h.This has afforded laminated veneer lumbers (LVLs) with improve mechanical properties, thermal and dimensional stability. LVLs were characterized through Fourier transformed infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. Effect of weight fraction (WF, wt%) of nanobentonite (NB) ranging 0 to 3.0 on mechanical properties, thermal and dimensional stability of LVLs was investigated with reference to PWVs as control. With WF of NB, the LVLs have rendered ultimate modification (%) in their flexural (80.49), tensile (63.81) and impact strength (18.35) at 2.0 WF of NB over PWVs. LVLs at 12 mm thickness with 2 WF of NB has rendered water resistance by 48.97% and thickness swelling (27.46%) over PWVs. Simultaneous thermogravimetric-differential thermal analysis (TG-DTA-DTG) reveals reduction in moisture content of LVLs ranging 4.92 to 1.4 with WF of NB. TG-DTA reveals onset temperature of degradation of LVLs at 200o C with marginal reduction in their heat of fusion over PVWs. DTG reveals thermal degradation (mg/min) of LVLs ranging 0.79 to 0.41 in the temperature range of 287.93 to 294.40oC. TG endset of LVLs was commenced in the temperature range of 485.78 to 600.68o C with heat of fusion (J/mg) ranging 49.5 to 50.8 and average char residue of 3.45% .The present study reveals sustainable modification of PWVs thorough adhesive boding with BENs to deliver the LVLs with improved durability, thermal and dimensional stability.ThesisItem Open Access Study on combustion, performance and emission characteristics of water emulsified fuels in C.I. engine(G.B. Pant University of Agriculture and Technology, Pantnagar, District Udham Singh Nagar, Uttarakhand. PIN - 263145, 2022-04) Gautam, Puneet Singh; Gupta, V. K.In this investigation, tests were carried out to standardize the constituent levels in order to achieve stable emulsions of aqueous and anhydrous alcohols with diesel fuel using Propylene Glycol Monostearate (PGM), Tween 80 as an emulsifier, and octanol as a coemulsifier. The phase separation and homogeneity of several emulsions were observed at room temperature (28°-34°C) and different temperatures ranges (0°-45°C). The engine's combustion, performance, emission characteristics, and combustion stability were evaluated on selected emulsion fuels on a computerized 1-cylinder, four-stroke, watercooled, direct injection diesel engine of constant engine speed. The engine performance was evaluated in terms of performance parameters such as brake power, brake specific fuel consumption, thermal efficiency, and combustion parameters such as cylinder pressure, HRR, ID, CD, MFB, etc. The emission parameters, CO, CO2, HC, NOx, and exhaust gas temperature, were evaluated. The engine's fuel consumption was found to be higher at all brake loads in case of emulsions selected for experimental investigations compared to diesel. Further, a single zone thermodynamic model was developed to predict the combustion characteristics such as in-cylinder pressure, heat release rate (HRR), using fundamental thermodynamic equations and various models. The success of the thermodynamic model was evaluated by statistical metrics (R², standard error (S), Pearson’s correlation (r), and P-value). The model accurately predicted the numerical results of cylinder pressure and HRR for diesel fuel and E50 emulsion at full loading condition. The statistical analysis of the predicted data by regression method and P-value showed strong evidence of significant data by this model. The mean values of the numerical data lay within 95% confidence interval in regression analysis for diesel at full loading condition.ThesisItem Open Access Effect of n-Pentanol addition to methanol-diesel blends on combustion stability, knock, performance and emission characteristics of diesel engine(G. B. Pant University of Agriculture and Technology, Pantnagar, 2021-12) Vishnoi, Pradeep Kumar; Gupta, V.K.The present study investigates the influence of n-pentanol addition to diesel/methanol blends on diesel engine performance, combustion, knock, and emission characteristics at different loading conditions. The experiments were performed for diesel and five different test fuels namely MnP5 (5% methanol+5% n-pentanol+90% diesel), MnP10 (10% methanol+10% n-pentanol+80% diesel), MnP15 (15% methanol+15% npentanol+80% diesel), MnP20 (20% methanol+20% n-pentanol+60% diesel) and MnP25 (25% methanol+25% n-pentanol+50% diesel). Performance characteristics were evaluated by using a fuel consumption test. Moreover, combustion and knock characteristics were evaluated based on in-cylinder pressure measurement and heat release analysis. Further, combustion stability analysis was conducted by using statistical and wavelet methods. The peak pressure data series was used for statistical and wavelet analysis. The results indicate that n-pentanol can stabilize the diesel-methanol blend and improve the properties of npentanol-methanol-diesel blends. The brake thermal efficiency for all test fuels and exhaust gas temperature for all test fuels was higher than that of the diesel. Longer ignition delay was observed for all the blends except MnP5 at lower load conditions, while shorter ignition delay was observed at high load conditions. Further, the ignition delay was increased with the increase in methanol and n-pentanol percentage in the test fuel blends. The peak pressure and rate of heat release for all the blends except Mn25 were higher than that of diesel at high load conditions. Knock, and ringing intensities for MnP5 were found to be higher than diesel at all loads. NOx emission for all the blends was lower than diesel at all loading conditions, while HC and smoke emission for MnP5 and MnP10 was lower than diesel at high load conditions. CO emission was found to be higher than diesel for all the blends at all loading conditions. Furthermore, coefficient of variation (COV), wavelet power spectrum (WPS), and global wavelet spectrum (GWS) power indicate that MnP25 exhibits very high cyclic variation.ThesisItem Open Access Experimental investigation of thermo-hydraulic performance of rotating packed bed using air-water system(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2022-04) Sandeep Kumar; Murthy, D.S.Rotating packed bed (RPB) has a great potential for process intensification in thermal systems. However, the available literature is only focused on its mass transfer aspects and no study shows its heat transfer aspects. In rotating packed bed, the water flows outwards from the inner periphery of a rotating rotor by centrifugal action and air travels inwards from the outer periphery by imposed pressure gradient making a counter current interaction with each other. The rotation of the rotor gives control over the water distribution unlike in conventional columns where gravity is the only driving force. In present work, rotating packed bed (RPB) have been explored for process intensification in thermal systems using air-water as working fluids. The thermo-hydraulic performance of rotating packed was carried out considering the air flow rate range varying from 0.007625 kg/s to 0.020175 kg/s, water flow rate varies from 0.033 kg/s to 0.133 kg/s and rotational speed considered is 0-2000 rpm. The thermal performance parameters such as cooling range, approach, water evaporation rate, heat transfer rate, Merkel number, and effectiveness for the RBP were experimentally evaluated for the given airflow rate, water flow rate and water inlet temperature (35, 40, and 45°C) and rotational speed. The optimum result for all the thermal performance parameters was observed at 1200 rpm. At the optimum condition, the observed value of cooling range was 15 ̊C, the value of approach was 12.2 ̊C, water evaporation rate was 0.000904 kg/s, effectiveness was 0.49 and the Merkel number was 0.426. The results were found to be in agreement with CTI (Cooling Technology Institute) performance curve charts, confirming the feasibility of RPBs to be used as thermal systems.ThesisItem Open Access Mechanical and thermal characterization of biodegradable cellulose nanofiber reinforced polyvinyl alcohol/chitosan blend(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-03) Somvanshi, Kritika Singh; Gope, P.C.In recent years, due to increased awareness and push towards more environmentally sustainable technology, nano-composite materials obtained from natural and renewable resources have received significant interest. Cellulose Nano Fiber (CNF) is the most profuse, recyclable and eco-friendly natural fiber which entirely disintegrated by the appropriate action of microorganisms. Polyvinyl Alcohol and Chitosan blend films were prepared by solution casting method and ultrasonic processing at 20, 30, 40 and 50 wt. % of CNF. The dispersion of Nano filler in a solution obtained by energetic agitation by the sonication process resulted in improved mechanical and thermal properties. The performance of the films was comprehensively investigated in terms of water absorption, mechanical properties, thermal stability, biodegradability, antimicrobial and antioxidant properties. DMA analysis of the film has been studied to determine the storage modulus, loss modulus and glass transition temperature. The homogeneous dispersion is studied using scanning electron micrographs. Optimization of different process parameters is studied using Analysis of Variance and Response Surface Methodology. The optimized film exhibited a strong antibacterial effect against Staphylococcus aureus bacterial strain with a 15.96 mm zone of inhibition diameter. Creep and recovery behavior were also examined and found that the rigidity and load-bearing capability are improved by CNF reinforcement. A soil burial test was conducted to investigate the biodegradability that shows improved degradation within a very short time. The improved results for mechanical, thermal, creep, antibacterial, antioxidant and biodegradability are recorded in the film with 30 min sonicated and 40 wt. % CNF reinforcement. The soil analysis results reveal that the optimized film can be used in various applications in the field of agriculture and food packaging.
