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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 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 Impact of surfactant modified ferrite nanoparticles on mechanical and thermal characteristics of epoxy(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2019-09) Singh, Ashtosh Kumar; Saxena, RakeshPresent investigation deals with development of surfactant modified ferrite nanoparticles (FNs) to achieve the epoxy ferrite composites (EFCs) bearing enhanced dispersion and compatibility of filler with epoxy matrix. This has afforded a series of EFCs with improved tensile, bending, compressive and impact strength. EFCs has shown improved hardness with characteristic reduction in their wear loss. However, a marginal increase in thermal stability of EFCs has been observed. Formation of surface modified FNs (SFNs) and their compatibility with epoxy matrix was clearly revealed through Fourier transformed infra- red spectra. Diversified microscopic methods in combination with X-ray diffraction spectra, magnetometry and DC conductivity experiments reveals enhanced dispersion of SFNs into EFCs. The overall experimental outcome reveals that SFNs (2 phr) imparts improved dispersion, compatibility with epoxy matrix that leads to the formation of EFCs with improved mechanical properties and controlled wear loss. Study further reveals that, EFCs developed through SFNs were of improved durability over those derived from FNs under identical filler loadings. Study finally disclose the importance of surfactants as modifiers for magnetically active fillers such as ferrites and their similar analogues making them suitable for development of high performance polymer nanocomposites suitable for the appliances useful for transportation, stealth and energy management, and biomedical applications.ThesisItem Open Access Mixed Mode I/II crack growth in dissimilar AA2024-T6 and AA7075-T6 friction stir welded joints(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-12) Tiwari, Saurabh; Gope, P.C.Aluminium alloy 7075 and 2024 are some of the widely used materials in the aerospace industry. In the present investigation, the effect of SiC nanoparticles on fatigue crack growth and mechanical properties were tested on friction stir welded specimens and compared with as-welded specimens. Fatigue test is performed on different loading angles i.e., 0°, 30°, 45°, 60° and 90° with Pmax= 2 kN, Pmin= 0.2 kN and frequency of 5 Hz with R=0.1 and cracks length is measured using a digital camera fitted on travelling tripod and then compared them with numerically calculated values. All specimens were solution annealed at 460 °C for 2 h and then the ageing heat treatment procedure was done at 170 °C for 16 hours. The experimental data obtained was used to plot stress-strain curve, a-N and da/dN vs. Keq curve and various fatigue crack growth parameters such as Paris crack growth constants, crack opening stress intensity factor, etc. were determined. The fatigue life was found to be 37000, 36500, 33000, 30000 and 28000 cycles for friction stir welded CTS specimen at 90°, 60°, 45°, 30° and 0° respectively in as-weld condition. It was observed that there is a significant variation in the variances of crack length increment after the incorporation of SiC nanoparticles. The fatigue life after SiC incorporation was found to be 48200, 39000, 36000, 34500 and 30000 cycles at 90°, 60°, 45°, 30° and 0° respectively. The values of material constants C and m are calculated through a single Paris Curve fit. Scanning electron microscope (SEM) study of fracture surface at different locations was carried out to investigate the different modes of fracture that occurred at different loading conditions and morphology test is used to investigate the grain size distribution at different welding zones.ThesisItem Open Access FEA-simulation to optimize laminated composite plate with cutout in free vibrations(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-02) Manuraj; Mishra, AnadiIn the present work, modelling and modal analysis is performed for laminated composite plates. A square plate of 1 meter edge length is studied. There are four boundary conditions considered, which are SSCC, SSCS, SSSS and SSCF. There are four types of standard lay which are considered, Symmetric Ply, Quasi Isotropic Ply, Cross Ply and Angle Ply. The study is performed in three parts as experiments. In the first part the plates are studied for modes which are significant in deformation in the z axis. It is found that 88% of the total modes considered have a very low contribution. The SSCF boundary condition has maximum modes which have higher contribution. In the second part plate with opening is studied. The opening types taken as circular, hexagonal, rectangular and square are studied. It is seen that circular opening is most suitable and square opening is least suitable among these shapes. Large variation occur for the boundary conditions SSCS, SSSS and SSCF and so they must be used after carrying out proper analysis on the basis of application. In the third part direct optimization is carried out for 1st mode frequency as objective function. Elliptical opening with different ratio for major and minor axis length and major axis orientation angle with the reference axis have been taken as parameter for optimization. It is observed that the length ratio of minor to major axis is higher for maximization case than that of minimization case. The orientation angle comes close to 90˚ for SSCF boundary condition. The study is done on the finite element analysis software ANSYS.ThesisItem Open Access Development and performance evaluation of a pine needle powder fired cookstove for hilly regions of Uttarakhand(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-01) Upadhyay, Bhawana; Tewari, P.C.Anything is waste as long as it is utilized. Every year chir pine (Pinus roxburghii) forests in Uttarakhand produces total two millions tonnes of pine needles which is locally called as “Pirul”. These pine needles are highly flammable because of high volatile matter. During summer these pine needles are burned sometime by villagers to clear the floor to allow the growth of green grass for animals and sometimes accidentally these needles catch fire and destroy the forest and releases large amount of greenhouse gasses to the atmosphere. Every year millions of tons of pine needles get burned and turn to ash, cause loss to environment and stop regeneration. Despite being very useful its potential is still untapped among rural people. Still in many villages, most of the energy demand of rural people are being fulfilled by burning the wood in very inefficient way. This is very harmful to the environment and villager’s health. By use of efficient biomass cook-stove the energy demand of the rural people can be fulfilled. Purpose of this research work is to harness the freely available biomass (pine needles). This work concerned with development of powdered fuel stove with improved efficiency and minimal emissions. The design of cookstove originates from a conventional sawdust stove. Water boiling test has been performed for evaluating the thermal efficiency of cookstove and a hood method were used to emission measurement. The thermal efficiency of stove when fired with pine needle powder and sawdust was 25.8 % and 24.4 % respectively. The maximum firepower of the stove with pine needle powder and & sawdust was 2.24 kW, 2.04 kW respectively. The average CO, emission with pine needle powder & sawdust were found 100, 282 PPM respectively. The average HC, emission with pine needle powder & sawdust were found 210, 332 PPM respectively.ThesisItem Open Access Exergy analysis of a PVT system having fins in air cooled channel(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-03) Pal, Sumit; Varshney, LokeshPhotovoltaic thermal (PVT) systems are systems are used to generate electrical energy and remaining energy lost as heat. One of the most critical parameters influencing the performance and life of PV panels is the temperature of photovoltaic (PV) cells. Higher cell temperature increases the waste heat that is not extracted, thus cell voltage/power decreases with an increase in cell temperature. By cooling the solar cell with a fluid stream like air/water/nano fluids, the electricity conversion can be increased. In addition to this, heat energy can be used for other applications such as space heating, drying of agricultural products, paint spraying and related processes. In present work, exergy analysis is done for a solar PVT system having fins in an air-cooled channel attached at the back of the PVT system. For this a 3-D numerical model is developed. Numerical simulations are achieved using ANSYS-Fluent software. The comparative study of air cooled channels with fins and without fins are performed considering two mass flow rates of air of 0.0085 kg/s and 0.0137 kg/s. The parameters such as panel temperature, inlet and outlet air flow temperatures in the air cooling channels are analyzed. Effect of duct depth on the panel temperature, thermal efficiency and exergy efficiency is analyzed. Also, roughness of the duct and fins surfaces on the panel temperature, thermal efficiency and exergy efficiency is analyzed. The results of the PVT system showed considerable improvement in thermal performance with using fin in air cooled channel. The maximum thermal performance observed 8.54 % at a mass flow rate of 0.0085 kg/s and 15.24 % at a mass flow rate of 0.0137 kg/s for the air cooled channel with fins. Subsequently, the maximum exergy efficiency was attained as 3.73 % at a mass flow rate of 0.0085 kg/s and 8.14 % at a mass flow rate of 0.0137 kg/s in air cooled channel with fins. However, the increment in duct depth decreases the thermal efficiency decreased by 0.6 % and exergy efficiency decreased by 0.5%.ThesisItem Open Access Comparative study on the melting rate of PCM for circular and semi-circular LHTES system(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-02) Amit Kumar; Verma, PrashantLatent heat thermal energy storage (LHTES) technique using different types of phase change materials (PCM) has become popular in the last few decades. It helps to reduce the problems related to discrepancy between supply and demand of energy. In the present study, the melting characteristics of a lauric acid in a semi-circular and circular latent heat storage unit has been studied. The low melting rate of PCM in the lower half of a circular heat storage unit can be enhanced by confining the PCM in the upper region by configuring the outer shell of semi-circular cross-section. The recent literature shows that no work has been carried out on the effect of the melting performance of PCM in a semi-circular LHTES unit. So, it has been decided to investigate the melting performance of PCM experimentally and numerically for semi-circular LHTES system. The investigation of the melting performance of PCM in a semi-circular heat storage unit has been done through by developing a numerical 2D model which has been analysed through ANSYS FLUENT. The results obtained from numerical simulation are validated through experimental results. The enhancement in the melting rate at three different inner tube position values (e = 0.20, 0.23 and 0.25) for inner tube from the bottom surface of outer semi-circular shell is investigated and it is found that the enhancement is maximum when the inner tube is nearest to the bottom surface of the outer shell i.e., for e = 0.20. The melting performance of PCM is also studied for different values of inlet temperature of heat transfer fluid for tube position e = 0.20 and it is observed that the increase in Stefan number, enhances the melting rate of PCM in semi-circular LHTES system. The semi-circular heat storage unit is also compared with circular heat storage unit by considering the equal quantity of PCM in both the cases. The semi-circular LHTES system shows enhancement in melting performance of PCM as compared to circular LHTES system. The semi-circular LHTES system melts the PCM completely in almost half time as compared to circular LHTES system. It is found that the thermal energy stored in PCM for semi-circular LHTES system is 416.4 KJ which is 12.04 % more as compared to TES of PCM for circular LHTES for the same time duration of 4800 sec and the thermal energy storage efficiency of semi-circular LHTES unit is 11 % more as compared to the circular LHTES unit.
