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K. Karunamurthy

Bio: K. Karunamurthy is an academic researcher from VIT University. The author has contributed to research in topics: Exergy & Impeller. The author has an hindex of 3, co-authored 14 publications receiving 33 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, an attempt was made to synthesize an environment-friendly nano-lubricant using virgin coconut oil as base fluid by separately blending Copper (Cu) and Silver (Ag) nanoparticles in concentrations of 0.1%, 0.25, 0.5% and 1% on the mass basis.

24 citations

Journal ArticleDOI
01 Oct 2020
TL;DR: In this paper, the pragmatic analysis of solar-assisted post-combustion carbon capture (SPCC) has been reviewed upon, where the energy compensation of a coal-fired plant due to regeneration of absorbent has been scrutinized.
Abstract: The world is undergoing a population explosion; urbanization has also taken giant leaps with higher standards of people. It is noted that the supply and the demand for energy have not been in correlation with one another, as around. When the supply of energy is scaled up, there will large amounts of emissions released from the power plants. Therefore, it is important to focus on capturing and storage of harmful greenhouse gas emissions, using renewable energy resources, so that emission mitigation can be made in an efficient and economically feasible way. The pragmatic analysis of solar-assisted post-combustion carbon capture (SPCC) has been reviewed upon, where the energy compensation of a coal-fired plant due to regeneration of absorbent has been scrutinized. It is also been compared with the integration of geothermal energy (GTCC) for carbon capture. In the adsorption process, various techno-economic analysis of Carbon Capture and Storage (CCS) integrating solar-assisted temperature swing adsorption has been reported along with the effect of absorbent material in pressure-temperature swing adsorption for CO2 capture. Assessment of solar-assisted CCS are also been accomplished by adopting pliable thinking on the energy system. Finally, the integration with solar thermal power plant using novel Sodium Carbonate as a solvent is discussed. Thus, several parts of the CCS system have been construed with renewable energy towards the goal of zero-emission power generation, which seems highly impossible, can be harnessed by 2050

7 citations

01 Jan 2016
TL;DR: In this paper, a linear relationship between the density and moisture content in several Malaysian lignocellulosic biomass residues from palm oil, rice (rice husk), coconut (coconut frond and shell) and sugar (sugarcane bagasse) industries and their potential function as a tool for moisture determination with reference to their density.
Abstract: Suspended moisture in raw biomass materials is undesired in biomass fuel applications. In commercial and industrial practices, the moisture content in biomass fuel is normally in between 10-20 by weight in order to maximize the heating value of the fuel. Determining the moisture content in biomass materials using the conventional oven-drying method is time consuming. This paper studied the linear relationship between the density and moisture content in several Malaysian lignocellulosic biomass residues from palm oil (oil palm frond, oil palm trunk, oil palm leaf, empty fruit bunch, palm mesocarp fiber and palm kernel shell), rice (rice husk), coconut (coconut frond and shell) and sugar (sugarcane bagasse) industries and their potential function as a tool for moisture determination with reference to their density. The biomass moisture content and density were determined through the oven drying method at 105°C and constant volume weighing at every 1-hour drying interval. All samples showed a linear relationship between moisture content and density, and a linear model for each biomass was constructed. The linear models were cross-validated using a set of measured observations to determine the prediction reliability and accuracy at 95 confidence interval. The cross validation regressions revealed the R2 and adjusted R2 values of above 0.9, while the standard error of regressions was found to be less than 3.1 wt. of moisture content for all linear models except for that of rice husk, indicating that the linear models are statistically reliable and accurate for moisture content determination using density. The average time of moisture determination using the density-moisture content models was found to be only between 45-60 minutes compared to the conventional drying method that took 24 hours to complete. © Universiti Malaysia Pahang.

6 citations

Journal ArticleDOI
TL;DR: In this paper, the authors reviewed the effects of different design modifications on the performance of a centrifugal pump and concluded that some design modifications of the impeller, diffuser, and casing result in improvement of functionality, efficiency, and reduction in pressure fluctuations, flow recirculation, and vibrations.
Abstract: Centrifugal pumps are one of the significant consumers of electricity and are one of the most commonly encountered rotodynamic machines in domestic and industrial applications. Centrifugal pumps operating at off-design conditions are often subject to different periodic flow randomness, which in turn hampers functionality and performance of the pump. These limitations can be overcome by modification in the conventional design of different components of a centrifugal pump, which can assuage flow randomness and instabilities, reconstitute flow pattern and minimize hydraulic flow losses. In this article, flow vulnerabilities like pressure and flow inconsistency, recirculation, boundary layer separation, adverse rotor–stator interaction, and the effects on operation and performance of a centrifugal pump are reviewed. This article also aims to review design modification attempts made by different researchers such as impeller trimming, rounding, geometry modification of different components, providing microgrooves on the impeller and others. Based on the findings of this study, it is concluded that some design modifications of the impeller, diffuser, and casing result in improvement of functionality, efficiency, and reduction in pressure fluctuations, flow recirculation, and vibrations. Design modifications should improve the performance without hampering functionality and useful operational range of the pump. Considerable research is still necessary to continue understanding and correlating flow physics and design modifications for the pump impeller, diffuser, and casing.

6 citations

Journal ArticleDOI
TL;DR: In this paper, the authors analyzed the energy and exergy distribution of a single-cylinder 199.5-cc electronic fuel injected three-spark ignited high-speed petrol engine.
Abstract: Numerous researchers have devised various strategies to improve the combustion efficiency of the internal combustion engine. Despite continuous improvement during past decades, there is still scope for further development in engine performance. This paper analyzes the energy and exergy distribution of a single-cylinder 199.5 cc electronic fuel injected three-spark ignited high-speed petrol engine. The engine is operated at 25%, 50%, 75%, and 100% throttle positions for different speeds of 4000–10,000 rpm with an increment of 2000 rpm. From the detailed heat balance analysis, the best results obtained are: maximum brake thermal efficiency of 34.9% corresponding to 6000 rpm at 50% throttle opening, minimum heat carried away by exhaust gas of 18.5% at 4000 rpm and 25% throttle position, minimum heat carried by cooling water as 13% for 10,000 rpm and 25% throttle, and the minimum unaccounted energy loss of 26.6% under the condition 8000 rpm and 75% throttle position. However, the best results of exergy analysis are: second law efficiency of 51.93% corresponding to 4000 rpm and 25% throttle, maximum exergy transfer for useful work as 33.7% concerning 6000 rpm and 50% throttle, minimum exergy transfer for exhaust gas as 15.7% for 6000 rpm and 25% throttle, minimum exergy transfer associated with coolant of 4.6% at 4000 rpm and 25% throttle, and minimum exergy destruction of 39.4% corresponding to 8000 rpm and 50% throttle, respectively.

4 citations


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TL;DR: In this article, the effect of the blending ratio, catalyst type, biomass type and catalyst to biomass loading on gas composition and heating value of the syngas was investigated for different WC/CS and WC/CF blends.
Abstract: Catalytic co-gasification is an important tar reforming technique, which may appreciably improve the quality of syngas through tar reforming reaction. In this study, wood chips (WC) were co-gasified with two coconut wastes, namely coconut shells (CS) and coconut fronds (CF), in a downdraft gasifier. The dolomite and limestone were used as tar reforming mediums. The effect of the blending ratio, catalyst type, biomass type and catalyst to biomass loading on gas composition and heating value of the syngas was investigated for different WC/CS and WC/CF blends. The results revealed that the WC/CS blending ratio of 70:30 produces the highest H2 amount (11.70 vol.%), which was 31% higher than the H2 amount of the other blends. The HHVsyngas of 70:30 blend was measured about 4.96 MJ/Nm3, which was also higher among all the tested blends. The co-gasification of 70:30 blend of WC/CS, when compared with same blending ratio WC/CF, produced two times higher CO, 60% higher H2 and 75% higher HHVsyngas. During catalytic co-gasification of WC/CS blends with dolomite and limestone, the dolomite yielded 24%, 13.8% and 25.6% increment in CO, H2, and CH4, respectively. It is concluded that the coconut wastes can be substituted or co-gasified with wood after carrying out some major changes in a gasifier geometry.

54 citations

Journal ArticleDOI
TL;DR: This review mainly summarizes the latest developments in the internal flow field and external characteristics of centrifugal pumps focused on turbulence and cavitation models, flow visualization methods, and fault detection based on noise and vibration.
Abstract: This review mainly summarizes the latest developments in the internal flow field and external characteristics of centrifugal pumps. In particular, the latest findings of centrifugal pumps focused on turbulence and cavitation models, flow visualization methods, and fault detection based on noise and vibration. The external characteristics, cavitation, and vibration of the centrifugal pump were extensively discussed. In addition, advanced multi-objective optimization methods for improving impeller’s efficiency and reducing net positive suction head (NPSH) were briefed. Although some progress was made in this field, there remain many unsolved problems, such as monitoring and modeling of cavitation, rotational stall phenomenon, and discrepancies between simulation and measurement. In the future, researchers are encouraged to employ multi-dimensional flow visualization technologies and high-performance computing facilities to advance existing understandings on these issues and create new research directions.

31 citations

Journal ArticleDOI
TL;DR: The results suggest that Cu modified by IL provides superior dispersion in PAO6 oil without sedimentation for 60 days, compared to unmodified Cu, and the hydrodynamic diameter of the modified Cu did not exceed 240 nm even after 60 days of preparation.

29 citations

Journal ArticleDOI
TL;DR: In this paper, the effect of nanoparticles as additives on the tribological properties of different base oils such as mineral oils, vegetable oils, and synthetic oils was discussed and the authors showed that the addition of multiple nanoparticles (0.1 to 0.5 kg) has indicated an improvement of 3 to 50% in these lubricating base oils under different testing conditions.

28 citations

Journal ArticleDOI
TL;DR: In this paper, a review article provided critical comments on biodegradable vegetable oil base fluid as one of the alternatives to non-renewable mineral oil as well it presents an overview of the remarkable research progress on conducting polymers base nanofluids witnessed in recent years.

28 citations