Real Gas Effects of Supercritical CO₂ Flow through a Supersonic Nozzle Senthil kumar Raman and Heuy Dong Kim

Senthil kumar Raman,Heuy Dong Kim 대한기계학회 2016 대한기계학회 춘추학술대회 Vol.2016 No.12

The unique characteristics of supercritical carbon dioxide (SCO₂) are reason enough to find its use in various engineering applications. But still usability of SCO₂ is not completely explored due to lack of knowledge about its real gas effects. The present study mainly addresses the real gas effects on supercritical CO₂ flow through a supersonic convergent-divergent nozzle. With series of theoretical equations which are based on one-dimensional gas dynamics theory, computer program has been developed to predict the compressible flow characteristics of supercritical CO₂. With the data obtained from the computer program, properties of supercritical CO₂ near critical point is theoretically analyzed with different EOS. Computational analysis also has been carried out to reasonably predict the SCO₂ flows. The deviation in prediction of properties of SCO₂ by a EOS from other one is addressed. Several types of the equations of state were applied to the compressible Navier-Stokes equations. For effective use of available EOS, an attempt is made by coupling ideal gas EOS and real gas EOS to analyze the real gas effect of SCO₂. These results are compared with the computational results of SCO₂ flow through convergent divergent nozzle with a single real gas EOS. The obtained solutions were used to investigate the generic features of supercritical CO₂ flow, in terms of shock wave location, flow choking, total pressure loss, pressure recovery, etc.

A Simple Method for Solving Type-2 and Type-4 Fuzzy Transportation Problems

Senthil Kumar, P. Korean Institute of Intelligent Systems 2016 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.16 No.4

In conventional transportation problem (TP), all the parameters are always certain. But, many of the real life situations in industry or organization, the parameters (supply, demand and cost) of the TP are not precise which are imprecise in nature in different factors like the market condition, variations in rates of diesel, traffic jams, weather in hilly areas, capacity of men and machine, long power cut, labourer's over time work, unexpected failures in machine, seasonal changes and many more. To counter these problems, depending on the nature of the parameters, the TP is classified into two categories namely type-2 and type-4 fuzzy transportation problems (FTPs) under uncertain environment and formulates the problem and utilizes the trapezoidal fuzzy number (TrFN) to solve the TP. The existing ranking procedure of Liou and Wang (1992) is used to transform the type-2 and type-4 FTPs into a crisp one so that the conventional method may be applied to solve the TP. Moreover, the solution procedure differs from TP to type-2 and type-4 FTPs in allocation step only. Therefore a simple and efficient method denoted by PSK (P. Senthil Kumar) method is proposed to obtain an optimal solution in terms of TrFNs. From this fuzzy solution, the decision maker (DM) can decide the level of acceptance for the transportation cost or profit. Thus, the major applications of fuzzy set theory are widely used in areas such as inventory control, communication network, aggregate planning, employment scheduling, and personnel assignment and so on.

A Simple Method for Solving Type-2 and Type-4 Fuzzy Transportation Problems

P. Senthil Kumar 한국지능시스템학회 2016 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.16 No.4

In conventional transportation problem (TP), all the parameters are always certain. But, many of the real life situations in industry or organization, the parameters (supply, demand and cost) of the TP are not precise which are imprecise in nature in different factors like the market condition, variations in rates of diesel, traffic jams, weather in hilly areas, capacity of men and machine, long power cut, labourer’s over time work, unexpected failures in machine, seasonal changes and many more. To counter these problems, depending on the nature of the parameters, the TP is classified into two categories namely type-2 and type-4 fuzzy transportation problems (FTPs) under uncertain environment and formulates the problem and utilizes the trapezoidal fuzzy number (TrFN) to solve the TP. The existing ranking procedure of Liou and Wang (1992) is used to transform the type-2 and type-4 FTPs into a crisp one so that the conventional method may be applied to solve the TP. Moreover, the solution procedure differs from TP to type-2 and type-4 FTPs in allocation step only. Therefore a simple and efficient method denoted by PSK (P. Senthil Kumar) method is proposed to obtain an optimal solution in terms of TrFNs. From this fuzzy solution, the decision maker (DM) can decide the level of acceptance for the transportation cost or profit. Thus, the major applications of fuzzy set theory are widely used in areas such as inventory control, communication network, aggregate planning, employment scheduling, and personnel assignment and so on.

Energy absorption of fibrous self compacting reinforced concrete system

Senthil, K.,Satyanarayanan, K.S.,Rupali, S. Techno-Press 2016 Advances in concrete construction Vol.4 No.1

The objective of the present work is to evaluate the influence of two different methods of improving the ductility of Reinforced Concrete Frames and their influence on the full range behavior of the frames with M40 grade of concrete. For this purpose one fourth scale reinforced concrete square frames are experimentally tested subjected to static cyclic loading for three cases and monotonic loading for one case. The parameters are varied as method introducing ductility to the frame viz. (i) by using conventional concrete (ii) adding 1% of steel fibres by volume of concrete at hinging zones (iii) using self-compacting concrete with fibres at hinging zones. The energy absorption by ductile and non-ductile frames has been compared. The behavior of frames tested under cyclic loading have revealed that there is a positive trend in improvement of ductility of frames when fibrous concrete is used along with self-compacting concrete.

Effect of Herbal Medicines on NFLD in Metabolic syndrome Subjects

( Senthil Kumar Subramani ),( Pratiba Chauchan ),( Rohit Sharma ),( Gbks Prasad ) 대한간학회 2021 춘·추계 학술대회 (KASL) Vol.2021 No.1

Experimental investigation of palm kernel fibre reinforced epoxy based composite

Senthil Kumar KM,Thirumalai Ramanathan,Seenivasan Murugesan,Venugopal Thangamuthu 한양대학교 세라믹연구소 2021 Journal of Ceramic Processing Research Vol.22 No.6

The composite specimen consisting of eight layers of palm kernel and coir fibers with different weight proportions wereprepared through hand lay-up technique. The experimental investigation of delamination factor, surface roughness, machiningforce and tool life are carried out in this work. The hand layup technique was used for the processing of the compositematerial, which constitutes the epoxy resin as the matrix material and fibre as the reinforcing material. Also silicon carbidewas added to the composite material in several percentages to increase the strength of the composite material. The specimenwas tested according to the testing standards and the values of surface roughness, delamination factor, machining force andtool life were recorded. ANOVA and Taguchi analysis for all responses were carried out and discussed here.

Characteristics of shock waves in non-ideal compressible fluid dynamics of supercritical CO₂

Senthil Kumar Raman,Simon Song 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.08

Influence of ultrasonication on preparation of novel material for heavy metal removal from wastewater

Senthil Kumar Ponnusamy,Saravanan Anbalagan,Sundar Rajan Panneer Selvam,Abishek Sankaranarayan,Abhishek Dutta 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.9

The present research introduces a new concept on rapid removal of Pb(II) ions from wastewater using novel agro-based material. The two types of materials such as sulfuric acid modified Caryota urens seeds (SMCUS) and ultrasonic assisted Caryota urens seeds (UACUS) were prepared and performance was compared for Pb(II) ions removal. The functional groups available on the C. urens were discussed by using FT-IR report. Adsorption influencing parameters such as initial metal ion concentration, pH, contact time, adsorbent dosage and temperature were studied to predict the optimum conditions. Several isotherm and kinetic models were applied to examine the experimental data. The present adsorption-adsorbate system best obeys the Freundlich and pseudo-first-order models. Langmuir monolayer capacity of the SMCUS and UACUS for Pb(II) ions was found to be 93.7 and 175.9mg/g, respectively. Thermodynamic parameters explain that the adsorption of Pb(II) ions was spontaneous and exothermic.

Influence of interface on the behavior of infilled frame subjected to lateral load using linear analysis

Senthil, K.,Satyanarayanan, K.S. Techno-Press 2016 Coupled systems mechanics Vol.5 No.2

Two dimensional numerical investigations were carried out to study the influence of interface thickness and their pattern on the behavior of reinforced concrete frames subjected to in-plane lateral loads using commercial finite element tool SAP 2000. The linear elastic analysis was carried out on one and two bay structural systems as well as the influence of number of stories was studied by varying the number of stories as single, three and five. The cement mortar was used as interface material and their effect was studied by varying thicknesses as 6, 8, 10, 14 and 20 mm. The interface was recognized as one sided, two sided, three sided and four sided and their effect was studied by removing the interface material between the reinforced concrete frame and masonry infill. The effect of lateral loads on infill masonry wall was also studied by varying assumed loads as 10, 20, 30, 40, 50 and 60 kN. The behavior of infilled frames studied has revealed that there is a maximum influence of interface thickness and interface pattern corresponding to 10 mm thickness. In general, the lateral displacement of frame is increased linearly with increase in lateral loads.

A new equation of state to predict S-CO 2 flow with real gas effects

Senthil Kumar Raman,김희동 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.3

The accuracy of the thermodynamic properties prediction from the different Equation of state (EOS) varies upon the range of temperature and pressure. Despite the variety of EOS available, there is no de facto for selecting an EOS for particular computational modeling. The EOS model recently developed by Kumar and Kim (K-K EOS) determines more accurately the thermodynamic properties of CO 2than earlier models. In this present study, K-K EOS is successfully implemented in the computational analysis of compressible supercritical CO 2 flow (S-CO 2 ) in the thermodynamic region near and away from the vapour-liquid critical point. Computational results of SCO 2 flow with the real gas properties predicted with the K-K EOS is compared with Span and Wagner (SW EOS) and ideal EOS.