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Optimization of active area of proton exchange membrane fuel cell with better water management
M. Karthikeyan,M. Muthukumar,P. Karthikeyan,C. Mathan 한양대학교 세라믹연구소 2019 Journal of Ceramic Processing Research Vol.20 No.5
Water flooding is one of the major issues which is influencing the performance of PEMFC, while scaling up the active area. Water accumulation in between the GDL and cathode flow field landing in PEMFC can be removed by fixing porous inserts along the landing area of the cathode flow field. In this paper, the optimum active area of the PEMFC is found from the experimental investigations of three active area sizes of 25 cm2, 36 cm2 and 70 cm2 with better water management by fixing porous inserts along the landing surface. All three active areas of PEMFCs with three different flow fields viz. Serpentine; Uniform and Stagger patterned pin types having porous inserts on cathode side have been investigated experimentally. The PEMFCs with active area of 25 cm2, 36 cm2 and 70 cm2 with stagger patterned pin types having porous inserts have obtained maximum power densities as 0.270 W/cm2, 0.338 W/cm2and 0.170 W/cm2 respectively. The PEMFC with active area of 36 cm2 yields higher power density compared to 25 cm2 and 70 cm2 PEMFCs. So it is found that the active area of 36 cm2 is the optimum active area of single cell PEMFC for maximum performance.
Rajagopal Karthikeyan,Kingni Sifeu Takougang,Kom Guillaume Honoré,Pham Viet-Thanh,Karthikeyan Anitha,Jafari Sajad 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.77 No.2
A chaotic simple jerk system (SJS) that belongs to systems with self-excited and hidden attractors is introduced in this paper. The dynamics of the proposed SJS is analytically and numerically investigated. Interestingly, the influence of the time delay on the proposed chaotic SJS is studied. In addition, the physical existence of self-excited and hidden chaotic attractors found in the proposed SJS and in the time-delayed form of SJSs (TDSJSs) are verified by using Orcard-PSpice software. Finally, chaos synchronization of identical, unidirectional, coupled, proposed chaotic TDSJSs is also reported.
Optimization of Drilling Characteristics for AI/SiC_p Composites Using Fuzzy/GA
Karthikeyan, R.,Jaiganesh, S.,Pai, B. C. 대한금속학회 2002 METALS AND MATERIALS International Vol.8 No.2
In this paper an attempt has been made to optimize the drilling characteristics for Al/SiCp composites using fuzzy logic and genetic algorithms (GA). The drilling characteristics studied were drill wear, specific energy and surface roughness. The parameters considered for the study include volume fraction of SiC in the aluminium matrix, cutting speed and feed rate. The experimental data was trained and simulated using fuzzy logic and optimization of cutting conditions were performed using genetic algorithms. The optimized cutting conditions were validated using confirmation experiments.
KARTHIKEYAN, K.,CHANDRAN, C.,TRUJILLO, J.J. The Korean Society for Computational and Applied M 2016 Journal of applied mathematics & informatics Vol.34 No.3
In this paper, we study boundary value problems for fractional integrodifferential equations involving Caputo derivative in Banach spaces. A generalized singular type Gronwall inequality is given to obtain an important priori bounds. Some sufficient conditions for the existence solutions are established by virtue of fractional calculus and fixed point method under some mild conditions.
Development of a Switched Diode Asymmetric Multilevel Inverter Topology
Karthikeyan, D.,Krishnasamy, Vijayakumar,Sathik, Mohd. Ali Jagabar The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.2
This paper presents a new asymmetrical multilevel inverter with a reduced number of power electronic components. The proposed multilevel inverter is analyzed using two different configurations: i) First Configuration (with a switched diode) and ii) Second Configuration (without a switched diode). The presented topologies are compared with recent multilevel inverter topologies in terms of number of switches, gate driver circuits and blocking voltages. The proposed topologies can be cascaded to generate the maximum number of output voltage levels and they are suitable for high voltage applications. Various power quality issues are addressed for both of the configurations. The proposed 11-level inverter configuration is simulated using MATLAB and it is validated with a laboratory based experimental setup.
Numerical modelling of dry-out in pulsating heat pipe using VOF model
Karthikeyan Cheiyar Palani,Deepakkumar Rajagopal 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.8
Operational limits are critical in the continuous functioning of a pulsating heat pipe (PHP). A computational fluid dynamics study was conducted to analyze the influence of working-fluid properties on the dry-out limit of closed-loop water-based PHP with a 50 % fill ratio. Working fluid (water) was boiled decisively at low temperature (35 °C) under reduced operating pressures to ease and analyze dry-out. Although, vapor pressure of water at 35 °C is 5.6 kPa; different evacuated pressures ranging from 2 to 10 kPa were attempted to validate the numerical model using different boiling characteristics and their influence on the dry-out phenomena. 2-D transient pressure based Navier-Stokes solver (ANSYS Fluent) was used to predict the field variables using the SIMPLE algorithm. The standard k-ϵ model with the enhanced wall treatment approach was used to capture the turbulent physics. VOF model was used to shape the two-phase flow characteristics. The adiabatic section was noticed to act as a functional barrier (for the pressure drop to occur) between evaporator and condenser sections. New concepts such as inverse flow dynamics, zero-gradient and equivalent points were established from time variation plots of working fluid properties.
Karthikeyan, Natesan Sundaramurthy,Sathiyanarayanan, Kulathu Iyer,Aravindan, Paduthapillai Gopal Korean Chemical Society 2009 Bulletin of the Korean Chemical Society Vol.30 No.11
The condensation of cyclic ketone with aromatic aldehydes in the presence of ammonium acetate under ethanol media affords the corresponding 5-aryl-7,8,13,14-tetrahydrodibenzo[a,i]phenanthridine with excellent yield. This mild and efficient procedure with high yield is also applied to the synthesis of 2,4-diaryl-6,7-benzo-3-azabicyclo- [3.3.1]nonan-9-ones and ${\alpha},{\alpha}{$’-bis(substituted benzylidene)cycloalkanones.