Applied Mechanics and Materials Vol. 787

Abstract: The present day’sresearch interests on bioenergy have been expanded rapidly due to oil crisis of 1980s. This bio energy should be available in locally and it’spurer than the fossil fuels. The field of bio energyis important for governments, scientists and business people in worldwide because of its available in nature and renewable resource. Todays the most important renewable energy is Biomass. The biological conversion of biomass to methane has become rapidly increasing in present days. All types of organic wastes can be converted to methane. In this study the installed plant is a sintex floating type biogas plant. The cubic capacity of plant is about 1000 liter. The pH range is maintained in the level of 6.8 to 7.5. The fermentation time of the anaerobic digestion for the efficient usage of gas as a fuel is about 30 days. Our biogas plant is used for all types of anaerobic respirating wastes such as cow dung manure, kitchen wastes etc.The input feed of kitchen waste is about 10 kg per day. The output of the biogas yield is about 0.714 m³/kg. The composition of biogas is 50% to 60% of methane and rather than remaining 30% to 40% CO₂ and small amount of water about 2% to 5%. The performance characteristics of biogas plant are studied in this paper. To evaluate the performance of biogas production and pH variation throughout this study.

Abstract: The thermal performances of photovoltaic thermal (PV/T) flat plate panel were determined under 500–1000 W/m² solar radiation levels. In the present work, fluid flow analysis and temperature distribution on solar panel has been carried out by experimental method and computational fluid dynamic (CFD) technique. The experiments have been carried out on clear days during the month April 2014. The geometric model for CFD analysis is generated using Solidworks. Mesh generation is accomplished by ANSYS Meshing Software. Physics setup, computation and post processing are accomplished by ANSYS FLUENT. The experimentally measured temperatures are compared to the temperatures determined by the CFD model and found to be in good agreement. It is also found that the difference between the experimental and CFD simulated outlet temperature differ only by less than 3.5°C.

Abstract: Basin type solar stills with top and bottom reflectors are presented and analysed experimentally for three days (23.03.14, 24.03.14, 25.03.14) at Anna University, Thoothukudi campus (8⁰ 48¹ N and 78⁰ 07¹ E), Tamil Nadu, India. Experiments were done simultaneously on four stills with different depths of water. The readings were taken from still with reflectors, still with reflectors and gravel, still with reflectors and pebbles and compared with the conventional still. The reflectors were inclined backwards at an angle of 45⁰. The results indicated that the productivity of the still with reflectors, still with reflectors and gravel and still with reflectors and pebbles was 29.92 %, 38.68 % and 41.60 % more than the conventional still. Also, it was found that the productivity of the still was highest with the minimum depth of water.

Abstract: This work is carried out to study the copper metal foam as porous wick structure in a flat heat pipe. The method of fabricating copper foam has been described. The characterization of copper foam has been carried out by scanning electron microscope (SEM) and X-Ray Diffractogram (XRD) analysis. Effect of liquid velocity on pressure drop and maximum capillary heat transport of fabricated copper foam has been presented.

Abstract: The present work deals with thermodynamic analysis of a R-134a/R-23 cascade refrigeration system to evaluate the maximum COP and the minimum temperature difference (D_T) corresponding to , by considering different operating parameters. The operating parameters includes: the condensing () and evaporating temperature () of R-134a and the condensing () and evaporating temperature () of R-23. A computational model has been developed for the considered system to evaluate the and D_T corresponding to based on the thermodynamic principles. A mutilinear regression analysis has been carried out to evaluate two correlations for calculating and minimum D_T considering the above operating parameters. The exergy analysis of the system is also performed to determine the irreversibility losses of the system as well as for the components. It has been found that the total exergy destruction rate of the system is lower at minimum .

Abstract: Solid waste management is one of the important areas focused by several researchers as it reduces environmental degradation, and offers useful or value added products. Fishery waste is significantly available in coastal areas and food processing industries which are a threat to the environment. Reuse or recycling is a better option to reduce the disposal of fishery waste. In this study, two different fishery wastes were investigated for their use for waste water treatment application. Chitosan was prepared from fishery and shrimp wastes by alkaline N-deacetylation process. Further Chitosan was characterised by the Fourier transform infra red analyser (FTIR), X-ray diffraction (XRD) and Viscosity-molecular weight. The FTIR results showed a more detailed structure of α-chitin in the region of O-H, N-H and CO stretching region. The FTIR spectrum was used to determine the chitosan degree of acetylation (DA).

Abstract: Abundant availability of solar energy and fast depleting fossil fuel reserves have necessitated deployment of large scale solar thermal systems for meeting the space heating, process heating and drying requirements. Researchers worldwide have focused on developing energy efficient dryer capable of enhancing product quality, reduced drying time, high throughput, minimal pre-treatments prior to drying with less energy loss in cost effective way. The present paper surveys literature on performance enhancement studies on solar dryer with a thrust on energy efficiency improvements in solar air collector and a multipurpose solar drying system. The effect of adoption of absorber plate with different types of fins, design modifications, CFD based optimization techniques and incorporation of storage materials have been reviewed. A dual-purpose solar water heating and drying system with phase change material (PCM) is suggested for effective harnessing of solar energy.

Abstract: Wind energy is one of the promising renewable energy resources. The challenges in utilizing the renewable energy sources are making them reliable with good efficiency. Wind turbine plays a major role in industrial power supply during heavy wind conditions. However, in domestic applications, the small scale wind turbine has major issue of low starting torque due to low wind speed near the ground surface. These conditions make the air motion as laminar flow with the Reynolds number less than 5x10⁵. Hence, in some adverse condition there is a laminar flow separation which increases the drag and consequently reduces the lift force. This paper gives a comprehensive review on the investigations that are being carried out on low Reynolds number regime aerofoil and laminar separation bubble to enhance the lift force especially at low wind speed conditions.

Abstract: Plastic has found an irreplaceable part in human life. Human produces plastic wastes continually which results in pollution. In this paper GLCM (Gray Level Co-occurrence Matrix) technique is used for plastic segregation. Plastic segregation is necessary for recycling; hence they have to be segregated from other wastes. Manufacturing plastics from recycled plastic products uses only two-third of the energy used to make plastics from virgin materials. By the variation in intensity levels of reflected light from the plastic wastes it is segregated. This type of waste management gains attention in recent days due to enormous increase in the wastes generated. Robotic arm controlled using vision system that uses GLCM technique is used for segregation. The GLCM property of contrast is calculated for the given sample and it is compared with the stored pre-defined value. On successful comparison with the given condition a signal is sent through the serial port to the 8051 microcontroller using USART (Universal Synchronous/Asynchronous Receiver/Transmitter) feature. On receipt of this signal, the microcontroller provides movement of the robotic arm by controlling the servo motors.

Abstract: The consumption of Portland cement for the production of concrete is rapidly increasing because of the remarkable growth in the construction worldwide. Cement production is an energy intensive process. The energy consumption by the cement industry is estimated to be about 5% of the total global industrial energy consumption. Manufacturing process of cement consumes enormous quantities of raw materials from limited natural resources at a high rate and leads to their depletion. Due to the dominant use of carbon intensive fuels such as coal, the cement industry is a major emitter of carbon dioxide and other air pollutants. The cement industry contributes about 6 % of global carbon dioxide emissions which is the primary source of global warming. In addition to carbon dioxide emissions, significant amount of nitrogen oxides, sulphur dioxide, carbon monoxide, hydrocarbons and volatile organic compounds are emitted during cement manufacturing and causes severe environmental issues. In this regard, effective control techniques for reduction in carbon dioxide emissions from modern cement industry and an efficient procedure to achieve sustainable cement manufacturing process are discussed in this paper.