Naga Sarada - Academia.edu (original) (raw)

Papers by Naga Sarada

Volume 6A: Energy, 2015

This paper reports performance evaluation of four–stroke, single–cylinder, water cooled, variable... more This paper reports performance evaluation of four–stroke, single–cylinder, water cooled, variable compression ratio (3–9), variable speed (2200–3000 rpm) spark ignition engine with brake power of 2.2 kW at a speed of 3000 rpm with copper coated combustion chamber (CCE) [copper-(thickness, 300 μ) was coated on piston crown, inner side of liner and cylinder head] with alcohol blended gasoline [20% methanol with 80% gasoline; 20% of ethanol with 80% of gasoline by volume) with varied spark ignition timing provided with catalytic converter with sponge iron as catalyst along with air injection and compared with engine with conventional combustion chamber (CE) with gasoline operation. Performance parameters and exhaust emissions (CO and UBHC) were evaluated at full load operation of the engine. Aldehydes (formaldehyde and acetaldehyde) were measured by wet method of 2,4, dinitrophenyle method at full load operation of the engine. Alcohol blended gasoline operation improved performance and...

International Journal of Automotive and Mechanical Engineering, 2012

In a country such as India, food grains, fruit, vegetables, meat, poultry and fish, are very susc... more In a country such as India, food grains, fruit, vegetables, meat, poultry and fish, are very susceptible to microbial contamination and spoilage and require stringent preservation methods. One such method is by the use of a chest freezer for the storage of frozen food. This investigation considers different loads and design parameters for the development of a chest freezer using R134a as the working fluid. Experimental designs of an evaporator coil, condenser coil and capillary tube are investigated through the development of storage periods in terms of steady state and cyclic performance, by optimising the quantity of refrigerant charge, with strict adherence to the standards and requirement for maintaining an internal temperature of-23 °C at 43 °C ambient. Cyclic load performance tests optimise the performance of individual components selected for the design of a chest freezer. The system selection has a highly balanced performance with R134a and showed 118 kJ/kg cooling capacity with 8.42 coefficient of performance (COP). By the replacement of R134a, temperatures of-23 °C are maintained inside the freezer cabinet with low power consumption and an increase in the net refrigerating effect, which in turn increases the COP. The system design has optimum efficiency with moderate costs by optimising the length and diameter of the evaporator coil, i.e., 34.15 m and 7.94 mm, respectively.

The present work deals with the results of the experimental investigations carried out on augment... more The present work deals with the results of the experimental investigations carried out on augmentation of turbulent flow heat transfer in a horizontal tube by the means of tube inserts, with air as working fluid. Experiments were carried out initially for the plain tube. Nusselt number and friction factor obtained experimentally were validated against those obtained from theoretical correlations. Secondly experimental investigations using five kinds (90 0 , 60 0 FW, 60 0 BW, 30 0 FW, 30 0 BW) of louvered square leaf inserts were carried out to estimate the enhancement of heat transfer rate for air in the presence of insert. Nusselt number and pressure drop increased, overall enhancement ratio is calculated to determine the optimum geometry of tube insert.

Alcohol (ethanol/ methanol) was carbureted through variable jet carbureter during suction stroke ... more Alcohol (ethanol/ methanol) was carbureted through variable jet carbureter during suction stroke and diesel was injected at the end of compression stroke for engine with LHR combustion chamber and performance, pollution levels and combusiton characteristics were compared with methanol operation over ethanol operation. Performance was improved with ethanol operation, while pollutoin levels were decreased with methanol operation at recommended injection timing and injector opening pressure..

Experiments were carried out to study the exhaust emissions of variable speed, variable compressi... more Experiments were carried out to study the exhaust emissions of variable speed, variable compression ratio, four- stroke, single cylinder, spark ignition (SI) engine having copper coated engine [CCE, copper-(thickness, 300/u) coated on piston crown and inner side of cylinder head] provided with catalytic converter with different catalysts of sponge iron and manganese ore with different test fuels of pure gasoline and gasohol (80% gasoline and 20% ethanol by volume) and compared with conventional engine (CE) with pure gasoline operation. Exhaust emissions of carbon monoxide (CO) and un-burnt hydro carbon (UBHC) were varied with different values of brake mean effective pressure (BMEP), speed, compression ratio with different operating conditions of catalytic converter with different catalyst. Aldehyde emissions were measured at peak load operation. CO and UBHC) were measured with Netel Chromatograph CO/UBHC analyzer. The engine was provided with catalytic converter with sponge iron and...

Indian Journal of Environmental Protection

Vegetable oils and alcohols are candidates for replacing diesel fuel as they are renewable in nat... more Vegetable oils and alcohols are candidates for replacing diesel fuel as they are renewable in nature. Alcohols can not be used directly in compression ignition engines as they have low cetane number. Vegetable oils have drawbacks of low volatility and high viscosity. The drawbacks associated with these fuels call for low heat rejection engines. The major pollutants emitted from diesel engine are smoke and oxides of nitrogen. Inhaling of these pollutants affect the human health apart from causing environment disorders. Investigations have been carried out on a low heat rejection (LHR) diesel engine with air gap insulated piston with superni (an alloy of nickel) crown and air gap insulated liner with superni insert with varied air gap thickness with carbureted methanol and crude jatropha oil at different injection pressures. The LHR diesel engine with carbureted methanol and crude jatropha oil decreased the pollution levels in comparison with vegetable oil operation on conventional en...

Pollution Research

Vegetable oils and alcohols are candidates for replacing diesel fuel as they are renewable in nat... more Vegetable oils and alcohols are candidates for replacing diesel fuel as they are renewable in nature. Alcohols can not be used directly in compression ignition engines as they have low cetane number. Vege' able oils have drawbacks of low volatility and high viscosity. The drawbacks associated with these fuels call for low heat rejection engines. The major pollutants emitted from diesel engine are smoke and oxides of nitrogen. Inhaling of these pollutants affect the human health apart from causing environment disorders. Investigations have been carried out on a low heat rejection (LHR) diesel engine with air gap insulated piston with supemi (an alloy of nickel) crown and air gap insulated liner with supemi insert with varied air gap thickness with carbureted methanol and crude pongamia oil at different injection pressures. The LHR diesel engine with carbureted methanol and crude pongamia oil decreased the pollution levels in comparison with vegetable oil operation on conventional...

Procedia Earth and Planetary Science, 2015

An air conditioning system utilizing solar energy would generally be more efficient cost wise, if... more An air conditioning system utilizing solar energy would generally be more efficient cost wise, if it was used to provide cooling requirement in the commercial and domestic as well as industrial buildings. And in twenty first century is rapidly becoming the perfect energy storm and the greatest challenge facing mankind is energy. The demand for energy

Aquatic Procedia, 2015

Although, more than two-thirds of the earth is covered with water and remaining is land, all over... more Although, more than two-thirds of the earth is covered with water and remaining is land, all over the world, access to potable water by the people is narrowing and decreasing day by day. Most of the human diseases are due to polluted or non purified water. Nowadays, each and every country is facing a problem of huge water scarcity because of pollution created by manmade activities. Adequate quality and reliability of drinking water supply is the fundamental need of all people on this earth. Fresh water which was obtained from rivers, lakes and ponds is becoming scarce because of industrialization and population explosion. Water purification using solar energy has become more popular because it is eco-friendly and cost effective. A solar still is commonly used device for water purification and it doesn't require any electricity for distillation of water. Solar distillation is a technology for producing potable water from brackish water or underground water of low quality at low cost. This method can reduce water scarcity problems in the world. In a solar still, water is evaporated using solar energy which is a form of renewable energy and collected as a distillate water after condensation of the vapour. This method can produce distilled water after removal of impurities. Since last three decades, more research work is going on to improve the system performance and efficiency of the solar still and provide a sustainable water purification. A variety of solar distillation devices have been developed with different materials and in different shapes in different locations to improve the efficiency of solar distillation. There is a strong need to improve the single slope solar still performance and increase the production of water distillation. The various factors affecting the productivity of solar still are: Climatic Parameters, Operational Parameters and Design Parameters. Among all these three parameters, main focus on the Operational Parameters; which are: Salinity, Mode of Operation, Amount of Dyes and Water Depth. From my literature survey, many researchers, engineers and scientists experimentally studied solar water distillation using Phase Change Materials (PCMs). There is no more work. So, this present paper is focused on performance of solar water distillation using Phase Change Materials. In this experiment Magnesium Sulfate Heptahydrate (MgSO 4 7H 2 O), Sodium Sulphate (Na 2 S 7H 2 O) are used as phase change material and Titanium oxide is a nano-material used for energy storage material. Among these energy storage materials Magnesium Sulfate Heptahydrate (MgSO 4 7H 2 O) improves the efficiency of solar water distillation.

Aquatic Procedia, 2015

Energy and water are necessity of mankind that influences the development of any nation. Today, t... more Energy and water are necessity of mankind that influences the development of any nation. Today, the production of fresh drinking water is a serious problem. Fresh water resources are becoming scarce due to population growth and pollution caused by industrial waste. Drinking water shortage is expected to become one of the biggest problems faced by world.With the continuous increase in the energy shortage and environmental pollution to reduce the mismatch between energy supply and energy demand, solar energy is one of the technologies which could be used as an alternative to the fossil fuel energy. Solar energy technologies are rapidly growing industries because it is one of the most reliable and readily available energy sources in the world. In most cases, the direct use of sea water is not possible because it is made up of different types of salts. Distillation is a well known thermal process for water purification and most importantly water desalination. Most of the conventional water distillation processes are highly energy consuming and require fossil fuels as well as electric power for their operation. Solar energy can be used to produce fresh water directly in a solar still or indirectly where the thermal energy from a solar energy system is supplied to solar still. One way to improve the energy utilization is to store the energy during sunshine times of higher solar incidence for later use of necessary needs. Efficient storage technologies are required to store energy for twenty four hours cycles to meet energy demand. Energy storage would enable to power generation for night periods and it helps match the generation and demand peaks.

Comparative studies were made on exhaust emissions of a four stroke, single cylinder, spark ignit... more Comparative studies were made on exhaust emissions of a four stroke, single cylinder, spark ignition (SI) engine, with gasohol having copper coated engine [CCE, copper-(thickness, 300 μ) coated on piston crown, inner portion of cylinder head] provided with improved design of catalytic converter with sponge iron as catalyst and compared with conventional SI engine (CE) with pure gasoline operation. Exhaust emissions of carbon monoxide (CO) emissions and un-burnt hydro carbons (UBHC) were determined at various values of brake mean effective pressure. A microprocessor–based analyzer was used for the measurement of exhaust emissions Copper coated engine with gasohol considerably reduced pollutants in comparison with CE with pure gasoline operation. Catalytic converter with improved design significantly reduced pollutants with gasohol on both configurations of the combustion chamber. Air injection in to the catalytic converter further reduced pollutants.

2008 First International Conference on Emerging Trends in Engineering and Technology, 2008

Page 1. Alternative Fuels for a Single Cylinder Direct Injection Diesel Engine K.Kalyani Radha, L... more Page 1. Alternative Fuels for a Single Cylinder Direct Injection Diesel Engine K.Kalyani Radha, Lecturer, JNTU, Hyderabad. kalyaniradha@gmail.com A. Aruna Kumari, Assoc. Prof, JNTU, Hyderabad. S.Naga Sarada, Assoc. Prof, JNTU, Hyderabad. ...

International Journal of Automotive and Mechanical Engineering, 2012

The present work shows the results obtained from experimental investigations of the augmentation ... more The present work shows the results obtained from experimental investigations of the augmentation of turbulent flow heat transfer in a horizontal tube by means of varying width twisted tape inserts, with air as the working fluid. In order to reduce excessive pressure drops associated with full-width twisted tape inserts, with a lower corresponding reduction in heat transfer coefficients, reduced-width twisted tapes of widths ranging from 10 mm to 22 mm are used, which are lower than the internal diameter of the tube of 27.5 mm. Experiments were carried out for plain tubes with/without twisted tape inserts at a constant wall heat flux and different mass flow rates. The twisted tapes are of three different twist ratios (3, 4 and 5), each with five different widths (26 (full-width), 22, 18, 14 and 10 mm). The Reynolds number varied from 6000 to 13500. Both the heat transfer coefficient and pressure drop are calculated, and the results are compared with those of a plain tube. It is observed that with the inclusion of twisted tape inserts there is a significant increase in the heat transfer coefficients. Correlations are developed for friction factors and Nusselt numbers for a fully-developed turbulent swirl flow, which are applicable to full-width as well as reduced-width twisted tapes, using a modified twist ratio as the pitch to width ratio of the tape.

Nanoscience and Nanotechnology Letters, 2012

ABSTRACT In the present investigation thermal conductivity of glycol based nanofluids with differ... more ABSTRACT In the present investigation thermal conductivity of glycol based nanofluids with different volume concentrations is experimentally determined in the temperature range of 30 to 70 °C. TiO2 nano material with average particle size of 21 nm is used for preparation of glycol based nanofluids. Base fluid used in the present investigation is a mixture of 60% water and 40% ethylene glycol by weight. Thermal conductivity of TiO2 nanofluids is measured for different volume concentrations in the range of 0.2%–1.0% of nanoparticles. Based on the experimental results, it is concluded that thermal conductivity of TiO2 nanofluids, considered in the present investigation, increases with increase in percentage of volume concentration of TiO2 and temperature.

Volume 2: Dynamics, Vibration and Control; Energy; Fluids Engineering; Micro and Nano Manufacturing, 2014

In recent years with the exacerbation of energy shortage around the world and the continuous incr... more In recent years with the exacerbation of energy shortage around the world and the continuous increase in the level of greenhouse gas emissions, the use of various sources of renewable energy is increasingly becoming important for sustainable development. Solar energy is considered to be one of the most promising sources of energy, owing to its clean and renewable characteristics. Thermal energy storage (TES) is used to assist in the effective utilization of thermal energy in wide number of industrial and domestic applications. Thermal energy is stored as sensible heat (SHS) or latent heat (LHS). Sensible heat storage (SHS) materials are combination of materials (both solids and liquids) which undergo no phase change in the defined temperature range of the storage process. Example concrete, cast steel, cast iron etc. The use of a latent heat storage system (LHS) using phase change materials (PCMs) is an effective way of storing thermal energy and has the advantages of high energy sto...

International Journal of Engineering, Science and Technology, 2011

The major problem with the direct use of vegetable oils as fuel into CI engines is their higher v... more The major problem with the direct use of vegetable oils as fuel into CI engines is their higher viscosity. It interferes the fuel injection and atomization and contributes to incomplete combustion, nozzle clogging, excessive engine deposits, ring sticking, producing thick smoke, etc. The problem of higher viscosity of vegetable oils can be overcome to a greater extent by various techniques, such as heating of fuel lines, trans-esterification, modification of injection system, etc. In the present investigation, short term tests were conducted with the use of untreated cotton seed oil in a single cylinder, four stroke, and direct injection diesel engine. Tests were conducted with cotton seed oil and diesel. To improve the combustion characteristics of cotton seed oil in an unmodified engine, effect of increase in injection pressure was studied. The injection pressure was increased from 180 bar to 240 bar (in steps of 15 bar). The investigation revealed that the optimum pressure for cottonseed oil as 210 bar and comparison of the performance of the engine was studied in terms of brake specific fuel consumption, brake thermal efficiency, indicated thermal efficiency, mechanical efficiency and exhaust emissions.

International Journal of Engineering, Science and Technology, 2011

The present work shows the results obtained from experimental investigations of the augmentation ... more The present work shows the results obtained from experimental investigations of the augmentation of turbulent flow heat transfer in a horizontal tube by means of varying width twisted tape inserts with air as the working fluid. In order to reduce excessive pressure drops associated with full width twisted tape inserts, with less corresponding reduction in heat transfer coefficients, reduced width twisted tapes of widths ranging from 10 mm to 22 mm, which are lower than the tube inside diameter of 27.5 mm are used. Experiments were carried out for plain tube with/without twisted tape insert at constant wall heat flux and different mass flow rates. The twisted tapes are of three different twist ratios (3, 4 and 5) each with five different widths (26-full width, 22, 18, 14 and 10 mm) respectively. The Reynolds number varied from 6000 to 13500. Both heat transfer coefficient and pressure drop are calculated and the results are compared with those of plain tube. It was found that the enhancement of heat transfer with twisted tape inserts as compared to plain tube varied from 36 to 48% for full width (26mm) and 33 to 39% for reduced width (22 mm) inserts. Correlations are developed for friction factors and Nusselt numbers for a fully developed turbulent swirl flow, which are applicable to full width as well as reduced width twisted tapes, using a modified twist ratio as pitch to width ratio of the tape.

European Journal of Mechanical and Environmental Engineering, 2010

The present work focuses on experimental and numerical investigations of the augmentation of turb... more The present work focuses on experimental and numerical investigations of the augmentation of turbulent flow heat transfer in a horizontal circular tube by means of mesh inserts with air as the working fluid. Sixteen types of mesh inserts with screen diameters of 22mm, 18mm, 14mm and 10mm for varying distance between the screens of 50mm, 100mm, 150mm and 200mm in the porosity range of 99.73 to 99.98 were considered for experimentation. The horizontal tube was subjected to constant and uniform heat flux. The ...

Volume 6A: Energy, 2015

International Journal of Automotive and Mechanical Engineering, 2012

Indian Journal of Environmental Protection

Pollution Research

Vegetable oils and alcohols are candidates for replacing diesel fuel as they are renewable in nat... more Vegetable oils and alcohols are candidates for replacing diesel fuel as they are renewable in nature. Alcohols can not be used directly in compression ignition engines as they have low cetane number. Vege' able oils have drawbacks of low volatility and high viscosity. The drawbacks associated with these fuels call for low heat rejection engines. The major pollutants emitted from diesel engine are smoke and oxides of nitrogen. Inhaling of these pollutants affect the human health apart from causing environment disorders. Investigations have been carried out on a low heat rejection (LHR) diesel engine with air gap insulated piston with supemi (an alloy of nickel) crown and air gap insulated liner with supemi insert with varied air gap thickness with carbureted methanol and crude pongamia oil at different injection pressures. The LHR diesel engine with carbureted methanol and crude pongamia oil decreased the pollution levels in comparison with vegetable oil operation on conventional...

Procedia Earth and Planetary Science, 2015

Aquatic Procedia, 2015

2008 First International Conference on Emerging Trends in Engineering and Technology, 2008

International Journal of Automotive and Mechanical Engineering, 2012

Nanoscience and Nanotechnology Letters, 2012

Volume 2: Dynamics, Vibration and Control; Energy; Fluids Engineering; Micro and Nano Manufacturing, 2014

International Journal of Engineering, Science and Technology, 2011

The present work shows the results obtained from experimental investigations of the augmentation ... more The present work shows the results obtained from experimental investigations of the augmentation of turbulent flow heat transfer in a horizontal tube by means of varying width twisted tape inserts with air as the working fluid. In order to reduce excessive pressure drops associated with full width twisted tape inserts, with less corresponding reduction in heat transfer coefficients, reduced width twisted tapes of widths ranging from 10 mm to 22 mm, which are lower than the tube inside diameter of 27.5 mm are used. Experiments were carried out for plain tube with/without twisted tape insert at constant wall heat flux and different mass flow rates. The twisted tapes are of three different twist ratios (3, 4 and 5) each with five different widths (26-full width, 22, 18, 14 and 10 mm) respectively. The Reynolds number varied from 6000 to 13500. Both heat transfer coefficient and pressure drop are calculated and the results are compared with those of plain tube. It was found that the enhancement of heat transfer with twisted tape inserts as compared to plain tube varied from 36 to 48% for full width (26mm) and 33 to 39% for reduced width (22 mm) inserts. Correlations are developed for friction factors and Nusselt numbers for a fully developed turbulent swirl flow, which are applicable to full width as well as reduced width twisted tapes, using a modified twist ratio as pitch to width ratio of the tape.

European Journal of Mechanical and Environmental Engineering, 2010