Simple and complex ultrasonic horns used in ultrasonic vibration-assisted friction stir welding a... more Simple and complex ultrasonic horns used in ultrasonic vibration-assisted friction stir welding are designed and analyzed using the finite element method. Modal analysis of the designs shows that the computed frequency in axial direction comes out ~ 19.5 kHz, that is close to the intended working frequency. The frequencies in the axial and non-axial direction make a large gap, eliminating the possibility of modal coupling. Safe design of the ultrasonic horn depends on amplitude and stress concentration at its end face. Harmonic response analysis of the designs reveals that the maximum ultrasonic amplitude occurs at the horn's small end. Besides, the maximum amplitude in case of the complex horn is lower than that of the simple horn, and the reduction in amplitude is appropriately discussed. The maximum von Misses stress on the horns is confined to a narrow region while the magnitude of maximum stress is lower than the yield strength of the respective material. The simulation results suggest that the designed simple and complex horns are safe within the design and metallurgical limits and are validated by real-time monitoring using laser vibrometer.
The objective of this study is to provide a quick review related to applications of ultrasonic vi... more The objective of this study is to provide a quick review related to applications of ultrasonic vibrations in friction stir welding processes that can significantly contribute to improving mechanical as well as microstructural properties. In the study, the current advantages, technological wakeups, limitations, and future prospects are deeply examined and evaluated for compressive understanding. The usage of ultrasonic vibration in friction stir welding is quite recent and require a thorough understanding to further enhance knowhow of its mechanisms.
This review article aims to analyze and evaluate the advantages, shortcomings, technological adva... more This review article aims to analyze and evaluate the advantages, shortcomings, technological advancements and hereafter prospects in welding and processing of magnesium and its alloys. Studies of containing metals with magnesium alloys will bring about in monumental weight reduction with significant addition in strength that could lead to dramatic transformation of metallic era of 21st century and onwards. However, wide application of Mg and its alloys depends on the development of advanced welding & joining technologies. The current paradigm and progress in welding, joining and processing of magnesium and its alloys are reviewed, and research trend in this field is briefly discussed.
—The Thermoacoustic deals with the conversion of sound energy to heat energy and vice-versa. In t... more —The Thermoacoustic deals with the conversion of sound energy to heat energy and vice-versa. In this study, fabrication of thermoacoustic system for refrigeration application was considered. This study comprises of two parts, in first part different components of thermoacoustic refrigerator are fabricated based on numerical design. Later performance of the device is then analyzed. The drop of 15.4°C was observed from the room temperature at the cold end of the stack within 330 seconds. It was also observed that, replacing the hot and cold heat exchangers, made the system more effective, reduced the complexity of the fabricated structure. Finally concluding the Performance of the Refrigerator, Coefficient of performance was calculated, and it came out be 0.69.
This review paper aims to introduce systematic in-depth analysis of diversified aspects of ultras... more This review paper aims to introduce systematic in-depth analysis of diversified aspects of ultrasonic application in metal joining and processing including its limitations, future prospects and assessments. Allied welding and metal processing technologies employing ultrasonic vibrations either as the primary source to accomplish the intended operation or as an assistant source to improve the operation efficiency and product quality are classified and discussed. The detailed state-of the art, experimentation and progresses of the ultrasonic vibrations and its applications in the above areas are comprehensively examined, evaluated and presented for exhaustive understandings of its physical mechanism. The ultra-sonic vibrations assisted processes claim several advantages such as improved mechanical properties, enlarged process window, higher heat generation, better material mixing and enhanced turbulence etc. over the conventional processes which lead to the remarkable and globalized applications of ultrasonic vibrations in the welding and its allied areas in the present century.
The increasing industrialization and motorization of the world has led to a steep rise for the de... more The increasing industrialization and motorization of the world has led to a steep rise for the demand of petroleum-based fuels. Petroleum-based fuels are obtained from limited reserves. These finite reserves are highly concentrated in certain regions of the world. Biodiesel has received, and continues to receive, considerable attention for its potential use as alternative fuels. Biodiesel is methyl or ethyl ester of fatty acid made from animal fat or vegetable oils. The main resources for biodiesel production can be non-edible oils obtained from plant species such as Jatropha curcas (Ratanjyot), Pongamia pinnata (Karanj), Calophyllum inophyllum (Nagchampa), Hevca brasiliensis (Rubber) etc. Application of biodiesel in diesel engine results in lower emissions. The fuel properties of biodiesel are very similar to the diesel fuel so it can work in existing infrastructure for conventional diesel without any modification in diesel engine. A wide range of diesel engine sizes and types was tested in the reviewed literature. This article provides a review on emission characteristics and comparison between the performance characteristics, efficiency of biodiesel and diesel engine in compression ignition (CI) engines.
The increasing energy development activities in the world impose the viability of pipeline for th... more The increasing energy development activities in the world impose the viability of pipeline for the safe and economical working. Pipelines mainly transport chemicals and hazardous fluids hence need to have very good safe track record and proved to be a safe and economical mean of carrying them. To lay down this platform, extensive research and development program has lead to appropriate design, selection of suitable materials and good operational practices. The optimization of selecting and evaluating coatings for feasible use in northern pipelines is of great importance with respect to the extreme environments to which the coated pipe may be subjected. Still failure occurs in pipelines due to some instants. Major cause of this failure includes crack formation and it's propagation over the surface of the pipe. Key cause behind these unwanted cracks is induced due to stressed corrosion cracking (SCC). The reasons behind SSC include the crevice loads, hydrogen embrittlement, residual stresses and film induce cleavage. The main objective of this article is to explore mechanisms and morphology of cracks propagation due to stress corrosion cracking to the pipe wall and its effect over the pipe span.
The future predicted scenario of energy crisis is emphasizing today on the development in the are... more The future predicted scenario of energy crisis is emphasizing today on the development in the area of energy saving, particularly in the high temperature engineering components such as gas turbines and Internal Combustion engines. Higher the operating temperature more is the efficiency of the system. However, increase in the operating temperature strictly affects the longevity of material. Use of certain ceramic layers as thermal barrier coatings (TBCs) over such high temperature components sufficiently reduces the heat penetration into the substrate and hence increases the efficiency and performance of the system. Further, high temperature stability is one of the key issues in this regard, which restricts the use of as such coating of ceramic layers and necessitates the use of some functionally graded materials (FGMs). This paper presents the need, status and effects of coatings of such functionally graded materials in improving performance of gas turbine systems and diesel engines. Certain coating techniques suitable in this context have also been discussed.
Simple and complex ultrasonic horns used in ultrasonic vibration-assisted friction stir welding a... more Simple and complex ultrasonic horns used in ultrasonic vibration-assisted friction stir welding are designed and analyzed using the finite element method. Modal analysis of the designs shows that the computed frequency in axial direction comes out ~ 19.5 kHz, that is close to the intended working frequency. The frequencies in the axial and non-axial direction make a large gap, eliminating the possibility of modal coupling. Safe design of the ultrasonic horn depends on amplitude and stress concentration at its end face. Harmonic response analysis of the designs reveals that the maximum ultrasonic amplitude occurs at the horn's small end. Besides, the maximum amplitude in case of the complex horn is lower than that of the simple horn, and the reduction in amplitude is appropriately discussed. The maximum von Misses stress on the horns is confined to a narrow region while the magnitude of maximum stress is lower than the yield strength of the respective material. The simulation results suggest that the designed simple and complex horns are safe within the design and metallurgical limits and are validated by real-time monitoring using laser vibrometer.
The objective of this study is to provide a quick review related to applications of ultrasonic vi... more The objective of this study is to provide a quick review related to applications of ultrasonic vibrations in friction stir welding processes that can significantly contribute to improving mechanical as well as microstructural properties. In the study, the current advantages, technological wakeups, limitations, and future prospects are deeply examined and evaluated for compressive understanding. The usage of ultrasonic vibration in friction stir welding is quite recent and require a thorough understanding to further enhance knowhow of its mechanisms.
This review article aims to analyze and evaluate the advantages, shortcomings, technological adva... more This review article aims to analyze and evaluate the advantages, shortcomings, technological advancements and hereafter prospects in welding and processing of magnesium and its alloys. Studies of containing metals with magnesium alloys will bring about in monumental weight reduction with significant addition in strength that could lead to dramatic transformation of metallic era of 21st century and onwards. However, wide application of Mg and its alloys depends on the development of advanced welding & joining technologies. The current paradigm and progress in welding, joining and processing of magnesium and its alloys are reviewed, and research trend in this field is briefly discussed.
—The Thermoacoustic deals with the conversion of sound energy to heat energy and vice-versa. In t... more —The Thermoacoustic deals with the conversion of sound energy to heat energy and vice-versa. In this study, fabrication of thermoacoustic system for refrigeration application was considered. This study comprises of two parts, in first part different components of thermoacoustic refrigerator are fabricated based on numerical design. Later performance of the device is then analyzed. The drop of 15.4°C was observed from the room temperature at the cold end of the stack within 330 seconds. It was also observed that, replacing the hot and cold heat exchangers, made the system more effective, reduced the complexity of the fabricated structure. Finally concluding the Performance of the Refrigerator, Coefficient of performance was calculated, and it came out be 0.69.
This review paper aims to introduce systematic in-depth analysis of diversified aspects of ultras... more This review paper aims to introduce systematic in-depth analysis of diversified aspects of ultrasonic application in metal joining and processing including its limitations, future prospects and assessments. Allied welding and metal processing technologies employing ultrasonic vibrations either as the primary source to accomplish the intended operation or as an assistant source to improve the operation efficiency and product quality are classified and discussed. The detailed state-of the art, experimentation and progresses of the ultrasonic vibrations and its applications in the above areas are comprehensively examined, evaluated and presented for exhaustive understandings of its physical mechanism. The ultra-sonic vibrations assisted processes claim several advantages such as improved mechanical properties, enlarged process window, higher heat generation, better material mixing and enhanced turbulence etc. over the conventional processes which lead to the remarkable and globalized applications of ultrasonic vibrations in the welding and its allied areas in the present century.
The increasing industrialization and motorization of the world has led to a steep rise for the de... more The increasing industrialization and motorization of the world has led to a steep rise for the demand of petroleum-based fuels. Petroleum-based fuels are obtained from limited reserves. These finite reserves are highly concentrated in certain regions of the world. Biodiesel has received, and continues to receive, considerable attention for its potential use as alternative fuels. Biodiesel is methyl or ethyl ester of fatty acid made from animal fat or vegetable oils. The main resources for biodiesel production can be non-edible oils obtained from plant species such as Jatropha curcas (Ratanjyot), Pongamia pinnata (Karanj), Calophyllum inophyllum (Nagchampa), Hevca brasiliensis (Rubber) etc. Application of biodiesel in diesel engine results in lower emissions. The fuel properties of biodiesel are very similar to the diesel fuel so it can work in existing infrastructure for conventional diesel without any modification in diesel engine. A wide range of diesel engine sizes and types was tested in the reviewed literature. This article provides a review on emission characteristics and comparison between the performance characteristics, efficiency of biodiesel and diesel engine in compression ignition (CI) engines.
The increasing energy development activities in the world impose the viability of pipeline for th... more The increasing energy development activities in the world impose the viability of pipeline for the safe and economical working. Pipelines mainly transport chemicals and hazardous fluids hence need to have very good safe track record and proved to be a safe and economical mean of carrying them. To lay down this platform, extensive research and development program has lead to appropriate design, selection of suitable materials and good operational practices. The optimization of selecting and evaluating coatings for feasible use in northern pipelines is of great importance with respect to the extreme environments to which the coated pipe may be subjected. Still failure occurs in pipelines due to some instants. Major cause of this failure includes crack formation and it's propagation over the surface of the pipe. Key cause behind these unwanted cracks is induced due to stressed corrosion cracking (SCC). The reasons behind SSC include the crevice loads, hydrogen embrittlement, residual stresses and film induce cleavage. The main objective of this article is to explore mechanisms and morphology of cracks propagation due to stress corrosion cracking to the pipe wall and its effect over the pipe span.
The future predicted scenario of energy crisis is emphasizing today on the development in the are... more The future predicted scenario of energy crisis is emphasizing today on the development in the area of energy saving, particularly in the high temperature engineering components such as gas turbines and Internal Combustion engines. Higher the operating temperature more is the efficiency of the system. However, increase in the operating temperature strictly affects the longevity of material. Use of certain ceramic layers as thermal barrier coatings (TBCs) over such high temperature components sufficiently reduces the heat penetration into the substrate and hence increases the efficiency and performance of the system. Further, high temperature stability is one of the key issues in this regard, which restricts the use of as such coating of ceramic layers and necessitates the use of some functionally graded materials (FGMs). This paper presents the need, status and effects of coatings of such functionally graded materials in improving performance of gas turbine systems and diesel engines. Certain coating techniques suitable in this context have also been discussed.
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