Analysis Of Heat Transfer Behavior Research Articles

Analysis of Heat Transfer Behavior of Porous Wavy Fin with Radiation and Convection by Using a Machine Learning Technique

The impact of convection and radiation on the thermal distribution of the wavy porous fin is examined in the present study. A hybrid model that combines the differential evolution (DE) algorithm with an artificial neural network (ANN) is proposed for predicting the heat transfer of the wavy porous fin. The equation representing the thermal variation in the wavy porous fin is reduced to its dimensionless arrangement and is numerically solved using Rung, e-Kutta-Fehlberg’s fourth-fifth order method (RKF-45). The study demonstrates the effectiveness of this hybrid model, and the results indicate that the proposed approach outperforms the ANN model with parameters obtained through grid search (GS), showcasing the superiority of the hybrid DE-ANN model in terms of accuracy and performance. This research highlights the potential of utilizing DE with ANN for improved predictive modeling in the heat transfer sector. The originality of this study is that it addresses the heat transfer problem by optimizing the selection of parameters for the ANN model using the DE algorithm.

Experimental analysis of heat transfer behavior of silver, MWCNT and hybrid (silver +MWCNT) nanofluids in a laminar tubular flow

Experimental investigations were carried out in order to study the heat transfer performance of silver (Ag), multiwalled carbon nanotubes (MWCNT) and silver (Ag) + multiwalled carbon nanotubes (Ag + MWCNTs) dispersed in distilled water. Nanofluids were synthesized and characterized using different techniques. Experimental facility was fabricated to validate the heat transfer performance of nanofluids in the laminar flow. The nanofluids were tested at mass concentrations of 0.02%, 0.05%, 0.1%, 0.2% and 0.5% for all the three nanofluids. Experimental average heat transfer coefficient was evaluated as a function of Reynolds number. The highest heat transfer augmentation of 67.5% was observed for 0.5 mass% MWCNT/distilled water nanofluids followed by 59.8% for hybrid Ag-MWCNT/distilled water nanofluids, and the least enhancement of 52.1% was observed with Ag/distilled water nanofluids for Reynolds number 2200. The hybrid nanofluids showed better enhancement compared to silver nanofluids. The heat transfer showed an increase with Reynolds number and particle loading. New correlations were developed for the nanofluids for heat transfer enhancement.

Experimental Analysis of Heat Transfer Behavior inside Heat Pipe Integrated with Cooling Plates

This work used experimental methods to study heat transfer behavior inside a heat pipe and found that heat transfer behavior inside the heat pipe was changed due to its integration with cooling plates. This change caused the heat pipe to have copper-like heat transfer behavior. Experimental performances first built a CPU simulator with maximum heat power 300 W in accordance with the ASTM standard as heat source and measured temperature distribution by using infrared thermography and thermocouple thermometer. Observation of heat transfer behavior inside heat pipe influenced by its integration with cooling plates used color schlieren technique. A commercial CPU heat pipe cooler was also used as reference object in this work. Integration of the heat pipe with cooling plates causes the heat pipe to have the copper-like heat transfer behavior. The results indicate that rebuilding the bare heat pipe’s heat transfer behavior is the best solution for improving cooling efficiency of the heat pipe cooler.

The variation of the metal/mold heat transfer coefficient along the cross section of cylindrical shaped castings

During solidification, the mathematical analysis of heat flow depends on the transient heat transfer coefficient at the metal/mold interface. The analysis of heat transfer behavior along a cylindrical section is necessary for a better control of solidification in conventional foundry and continuous casting processes. For this purpose, a water-cooled experimental apparatus was developed, and experiments were carried out with Sn–Pb alloys with different melt superheats. The heat transfer coefficients were determined by a theoretical–experimental fit of thermal profiles (IHCP). The results have shown a variation in heat flow conditions along the metal/mold interface provoked by the action of solidification thermal contraction connected with the gravitational effect. In macrostructural terms, this effect was evident with an asymmetric structure due to the variation of metal/mold thermal contact along the cylinder cross section. Experimental equations correlating heat transfer coefficients as a power function of time along the cross section of cylindrical horizontal castings of Sn–Pb alloys are proposed.

Factors affecting solidification thermal variables along the cross-section of horizontal cylindrical ingots

During solidification the mathematical analysis of heat flow depends on the transient heat transfer coefficient at the metal/mold interface. The analysis of heat transfer behavior along the cross-section of radial geometries is necessary for a better control of solidification in conventional foundry and continuous casting processes. For this purpose, a water-cooled solidification experimental apparatus was developed, and experiments were carried out with Sn–Pb alloys with different melt superheats. The transient metal/mold heat transfer coefficients were determined by a numerical-experimental fit of casting thermal profiles based on inverse heat transfer calculations. The results have shown a significant variation in heat flow conditions along the cylinder cross-section provoked by the simultaneous action of solidification thermal contraction and the gravitational effect. Experimental equations correlating heat transfer coefficients as a power function of time along the cross-section of cylindrical horizontal castings of Sn–Pb alloys are proposed.

Convective heat transfer in a curved annular-sector duct

A numerical analysis of heat transfer behavior in a curved annular-sector duct is presented in this article. A uniform axial heat flux and constant peripheral wall temperature boundary condition are applied in this study. The effects of three major parameters on the heat transfer process (the axial pressure gradient, the dimensionless radius ratio, and the dimensionless curvature) are systematically studied. The results indicate that completely different temperature distribution patterns are evident among the segmented duct in different locations relative to the symmetrical center line. The Nusselt number significantly increases as the pressure gradient increases. Furthermore, an increase of the dimensionless curvature will also enhance heat transfer because of a strong secondary flow. Finally, the results indicate that heat transfer is improved dramatically as the duct radius ratio decreases, especially when the duct radius ratio is smaller than 0.6.