Saroj Kumar Mohapatra

Bio: Saroj Kumar Mohapatra is an academic researcher from Thapar University. The author has contributed to research in topics: Diesel fuel & Biodiesel. The author has an hindex of 21, co-authored 112 publications receiving 1266 citations.

Effect of channel and plenum aspect ratios on the performance of microchannel heat sink under different flow arrangements

Abstract: Microchannels based heat sinks are considered as potential thermal management solution for electronic devices. The overall thermal performance of a microchannel heat sink depends on the flow characteristics within microchannels as well as within the inlet and outlet plenum and these flow phenomena are influenced by channel aspect ratio, plenum aspect ratio and flow arrangements at the inlet and outlet plenums. In the present research work an experimental investigation has been carried out to understand how the heat transfer and pressure drop attributes vary with different plenum aspect ratio and channel aspect ratio under different flow arrangements. For this purpose microchannel test pieces with two channel aspect ratios, 4.72 and 7.57 and three plenum aspect ratios, 2.5, 3.0 and 3.75 have been tested under three flow arrangements, namely U-, S- and P-types. Test runs were performed by maintaining three constant heat inputs, 125 W, 225 W and 375 W in the range 224.3 ≤ Re ≤ 1121.7. Reduction in channel width (increase in aspect ratio, defined as depth to width of channel) in the present case has shown about 126 to 165% increase in Nusselt number, whereas increase in plenum length (reduction in plenum aspect ratio defined as width to length of plenum) has resulted in 18 to 26% increase in Nusselt number.

Investigation on centrifugal slurry pump performance with variation of operating speed

Abstract: In this paper three-dimensional fluid flow behavior of centrifugal slurry pump has been studied using commercial Computational Fluid Dynamics (CFD) code FLUENT at design and off-design conditions. Steady state simulation with Moving Reference Frame (MRF) model is used to consider impeller-volute interaction. Different turbulence models namely, standard k- , RSM, k- and RNG k- are applied for simulation of flow through the pump, which show reasonably close prediction of head –flow characteristics of pump by kmodel. Performance characteristics of the pump is numerically predicted at four different operating speeds namely 1000 rpm, 1150 rpm, 1300 rpm and 1450 rpm with water. The numerical results are compared with the experimental measurements. The comparison indicates that the specific head, specific power and efficiency characteristics prediction are within an error band of 5 %. Simulation results showed that standard affinity relations are applicable to the slurry pump also.

Simulation of Erosion Wear in Slurry Pipe Line Using CFD

Abstract: Erosion is a serious problem faced in many industries that includes the transport of sand and water slurry in slurry pipe line. This paper emphasizes on the investigation of erosion on a mild steel straight pipe at different parameters including fluid velocity, particle size and concentration. The fluid velocity is selected in the range of 2.5-10 m/s using computational fluid dynamics code ANSYS-CFX. Sand particle within the size range of 100-400 µm size and concentration 5%-15% are used in this study. An Euler-Lagrange approach is used to solve the multiphase flow phenomenon. A horizontal pipe of diameter 100 mm and length 1 m (10 times of diameter) is considered for the study. The stochastic model of Sommerfeld will be used to account the wall roughness of pipe. It is also observed that the erosion wear in the pipeline strongly depends on fluid velocity, particle size and concentration.

A comprehensive review on biodiesel as an alternative energy resource and its characteristics

Abstract: As the fossil fuels are depleting day by day, there is a need to find out an alternative fuel to fulfill the energy demand of the world. Biodiesel is one of the best available resources that have come to the forefront recently. In this paper, a detailed review has been conducted to highlight different related aspects to biodiesel industry. These aspects include, biodiesel feedstocks, extraction and production methods, properties and qualities of biodiesel, problems and potential solutions of using vegetable oil, advantages and disadvantages of biodiesel, the economical viability and finally the future of biodiesel. The literature reviewed was selective and critical. Highly rated journals in scientific indexes were the preferred choice, although other non-indexed publications, such as Scientific Research and Essays or some internal reports from highly reputed organizations such as International Energy Agency (IEA), Energy Information Administration (EIA) and British Petroleum (BP) have also been cited. Based on the overview presented, it is clear that the search for beneficial biodiesel sources should focus on feedstocks that do not compete with food crops, do not lead to land-clearing and provide greenhouse-gas reductions. These feedstocks include non-edible oils such as Jatropha curcas and Calophyllum inophyllum , and more recently microalgae and genetically engineered plants such as poplar and switchgrass have emerged to be very promising feedstocks for biodiesel production. It has been found that feedstock alone represents more than 75% of the overall biodiesel production cost. Therefore, selecting the best feedstock is vital to ensure low production cost. It has also been found that the continuity in transesterification process is another choice to minimize the production cost. Biodiesel is currently not economically feasible, and more research and technological development are needed. Thus supporting policies are important to promote biodiesel research and make their prices competitive with other conventional sources of energy. Currently, biodiesel can be more effective if used as a complement to other energy sources.

Non-edible vegetable oils: A critical evaluation of oil extraction, fatty acid compositions, biodiesel production, characteristics, engine performance and emissions production

Abstract: World energy demand is expected to increase due to the expanding urbanization, better living standards and increasing population. At a time when society is becoming increasingly aware of the declining reserves of fossil fuels beside the environmental concerns, it has become apparent that biodiesel is destined to make a substantial contribution to the future energy demands of the domestic and industrial economies. There are different potential feedstocks for biodiesel production. Non-edible vegetable oils which are known as the second generation feedstocks can be considered as promising substitutions for traditional edible food crops for the production of biodiesel. The use of non-edible plant oils is very significant because of the tremendous demand for edible oils as food source. Moreover, edible oils’ feedstock costs are far expensive to be used as fuel. Therefore, production of biodiesel from non-edible oils is an effective way to overcome all the associated problems with edible oils. However, the potential of converting non-edible oil into biodiesel must be well examined. This is because physical and chemical properties of biodiesel produced from any feedstock must comply with the limits of ASTM and DIN EN specifications for biodiesel fuels. This paper introduces non-edible vegetable oils to be used as biodiesel feedstocks. Several aspects related to these feedstocks have been reviewed from various recent publications. These aspects include overview of non-edible oil resources, advantages of non-edible oils, problems in exploitation of non-edible oils, fatty acid composition profiles (FAC) of various non-edible oils, oil extraction techniques, technologies of biodiesel production from non-edible oils, biodiesel standards and characterization, properties and characteristic of non-edible biodiesel and engine performance and emission production. As a conclusion, it has been found that there is a huge chance to produce biodiesel from non-edible oil sources and therefore it can boost the future production of biodiesel.

Recent advances in the development of biomass gasification technology: A comprehensive review

Abstract: Due to fast climate change and foreseen damage through global warming, access to clean and green energy has become very much essential for the sustainable development of the society, globally. Biomass based energy is one of the important renewable energy resources to meet the day to day energy requirements and is as old as the human civilization. Biomass gasification is among few important aspects of bioenergy for producing heat, power and biofuels for useful applications. Despite, the availability of vast literature, technological and material advancements, the dissemination of gasification technology could not overcome the critical barriers for the widespread acceptability over the conventional energy resources. This article presents a comprehensive review on the technical advancements, developments of biomass gasification technology and the barriers being faced by different stakeholders in the wide dissemination of the technology for day to day requirements of the society, followed by recommendations for policy makers to make this technology popular while serving the society.

Biomass and bioenergy

Abstract: Plant biomass are woody and non-wood materials (e.g., oil palm, bamboo, rattan, bagasse, and kenaf) and are abundant and renewable resource. Unfortunately, the heavy reliance on this resource is a threat to forest ecosystems and a recipe for accelerated land resource degradation. Due to the increasing scarcity of wood resources, many rural communities have shifted to utilization of crop residues for many different applications. The non-wood biomass is readily available, environmental friendly, and technologically suitable, and therefore, an excellent raw material for the future. The non-wood materials like bamboo, rattan, oil palm, and bagasse have superior properties and durability, which can be further prolonged by the modifi cation treatment. The modifi cation treatments increase the performance of the non-wood and could make it suitable for applications in many fi elds ranging from construction industry to automotive industry. This chapter deals with the properties improvement techniques of the selected non-wood biomasses and evaluates its applications for various purposes. The new developments dealing with the improvement of non-wood properties have also been presented in the chapter. The performance of non-wood biomass materials has been compared to the wood-based materials. Recent studies pertaining to the above topics have also been cited. Finally, the advanced applications of the improved non-wood biomasses have been highlighted.