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In the present work, the effect of channel cross section on the heat transfer performance of an oblique finned micro-channel heat sink was investigated. Water and Al 2 O 3 /water nanofluid of volume fraction 0.25% were used as a coolant. The oblique finned microchannels are designed with three channel cross-sections namely square, semicircle and trapezoidal. The primary work of this paper is to study the heat transfer and hydrodynamic characteristics in the oblique finned microchannel. The experimental setup and procedure are validated using water as coolant in a micro-channel heat sink. Heat transfer and flow characteristics are examined for three cross-sections of varying mass flux. The trapezoidal channel cross-section increases the considerable heat transfer rate improvement for both water and nanofluid by 3.133% and 5.878% compared to square and semicircle cross section. Also, the pressure drop is higher in the trapezoidal cross-section over the square and semicircle cross section. This is due to increase in friction loss of trapezoidal cross section. The results indicate that trapezoidal cross-section oblique finned micro-channel is more suitable for heat transfer in the electronic cooling application. [ABSTRACT FROM AUTHOR]

The significant development of power converters in electric vehicles demands higher energy consumption and in turn larger heat generation. To prevent overheating of power converters, a newly designed curved microchannel is being developed with different cooling fluids. The objective of present experimental study is to analyze the heat transfer characteristics of oblique finned curved microchannel heat sink (MCHS) with various working fluids like Deionized water, nanofluid and hybrid nanofluid. Here heat sink has been designed with cross sectional area of 80 × 53 mm2. The DI water, Al 2 O 3 /water nanofluid and Al 2 O 3 +CuO/water hybrid nanofluid was utilized separately with rate of mass flow varied between 0.1 and 0.5 lpm maintaining steady heat flux of 25.5 kW/m2. Investigational output exposed that the rate of heat transfer, PEC and fall in pressure for the curved MCHS enhanced by 11.98%, 16.5% and 30.1% respectively in comparison to the heat sink which has straight channel. Also using hybrid nanofluid, the rate of heat transfer increased by 3.5% and 2.1%with curved MCHS in comparison to water and nanofluid. This is endorsed to the secondary flow generated by curved MCHS which improved the rate of heat transfer significantly. Overall, the curved MCHS with hybrid nanofluid is suggested as a preferred cooling medium for power converter in electric vehicles. • The rate of transfer of heat and flow character of oblique finned curved MCHS was studied experimentally. • The mass flow rate of DI water,Al 2 O 3 /water nanofluids and Al 2 O 3 +CuO/water hybrid nanofluid was varied to understand the effect on rate of heat transfer, PEC and fall in pressure. • The consequence of heat-transfer rate and drop in pressure of curved microchannel was studied and it reveals that the curved channel is comparatively more efficient than straight channel. [ABSTRACT FROM AUTHOR]

Modeling of level process in various tanks and vessels is one of the most common problems in the process industry. In this paper, system identification process is attempted for CSTH tank process. The CSTH tank process is a classic example of a highly nonlinear system. For nonlinear systems, System identification provides a better alternative to find their system transfer function. First principle modeling of level process is done with so much of assumption. System identification procedure gives accurate model. Inflow rate is taken as the input data and process level is taken as the output for CSTH tank. Collected data is fitted to transfer function model set. The simulation is performed in the MATLAB environment using System Identification coding and then worked on FOPID control toolbox. We have found practically the model of the CSTH tank using the MATLAB environment which gives the results almost identical to the ideal model of the plant. The system identification process is used here to identify the nature of the system using the inputs and the outputs available. After this identification process best control can be chosen with a comparative analysis and then the controller can be implemented. [ABSTRACT FROM AUTHOR]

The current investigation compares the heat transfer and flow characteristics of an oblique finned microchannel heat sink (MCHS) having newly designed pentagonal, triangular cross-sections. The working fluids used are CuO/Water (0.3%), Al 2 O 3 /Water (0.3%) nanofluids and Al 2 O 3 -CuO/Water (0.3%) Hybrid nanofluid. The heat sink has a cross-sectional area of 80 × 48 mm2 and the experimental study was carried out by varying the mass flow rate from 0.1 to 0.5 LPM with a constant heat flux of 50 kW/m2. The experimental results revealed that the heat transfer rate and pressure drop for the pentagonal channel increased by 12.3% and 16.5% respectively when compared to the triangular channel heat sink using hybrid nanofluids which can be credited to the secondary flow generated in the oblique finned pentagonal microchannel heat sink. Also with hybrid nanofluid, the heat transfer rate enhanced by 4.2% and 5.5% with pentagonal microchannel heat sink when compared to Cuo/Water and Al 2 O 3 /Water nanofluids respectively. The Performance Evaluation Criterion for the pentagonal microchannel heat sink is found to be 21.12% higher than the triangular microchannel heat sink using hybrid nanofluid. The thermal resistance was found to be less and the pumping power required was found to be high for pentagonal channel heat sink with hybrid nanofluid when compared to other combinations. [ABSTRACT FROM AUTHOR]

A facile galvanic replacement approach was successfully adopted to design trimetallic CuPtAu nanotubes (NTs) using pre-synthesized Cu nanowires (Cu NWs) as a partial sacrificial template. It was observed that both galvanic replacement reaction and Kirkendall effect played a crucial role for the formation of trimetallic CuPtAu NTs. The morphological studies clearly confirmed that formation of well-defined trimetallic CuPtAu NTs. The prepared trimetallic NTs exhibited remarkable methanol oxidation performance compared to that of commercial Pt/C catalyst. A maximum current density of 1959.67 mA/mg Pt −1 was achieved, which was ∼4.2 fold higher than commercial Pt/C catalyst. This strategy can be adopted for the synthesis of Pt-based metallic nanotubes for efficient MOR activity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bi 2 WO 6 /TiO 2 nanorod heterojunction photocatalyst was prepared by ultrasonication assisted impregnation method. • The Bi 2 WO 6 /TiO 2 nanorod photocatalyst showed 13 folds enhancement in H 2 production than P25. • A direct Z-scheme heterojunction for charge transfer mechanism is proposed. In this work, Bi 2 WO 6 /TiO 2 nanorod heterojunction was prepared by sonochemical assisted impregnation method. After loading 2 wt% Bi 2 WO 6 on TiO 2 nanorods, the photocatalytic hydrogen production rate of 2026 µmol/h/g was achieved. Compared to commercial P25 and TiO 2 nanorods, ∼13 and ∼3 folds enhanced activity was observed. The excellent photocatalytic performance of Bi 2 WO 6 /TiO 2 nanorod photocatalyst was mainly attributed to i) reduction of bandgap due to heterojunction formation, ii) quick transport of photogenerated charge carriers, and iii) efficient charge carrier separation supported by UV-DRS, photocurrent measurement, Impedance study, and photoluminescence spectra analysis. The Z-scheme band alignment for Bi 2 WO 6 /TiO 2 nanorod heterojunction was proposed based on the Mott-Schottky measurement. This result demonstrated the effective utilization of Z-scheme heterojunction of Bi 2 WO 6 /TiO 2 for photocatalytic reduction application. [ABSTRACT FROM AUTHOR]