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Existing pulsating heat pipes (PHPs) have a closed loop on a two-dimensional (2D) plane, leading to a structural limit in heat transfer performance. This study solves the limitations of these existing PHPs by substituting a specific three-dimensional (3D) structure PHP. The numerical model (having a 2D structure PHP) was validated with the experiment, which shows the maximum error of 8.5 % in the results. Results show that additional flow occurred due to the 3D structure of the PHP, which enables improved heat transfer. Under uniform heating conditions, the thermal resistance and the temperature of the evaporator decreased by up to 14.7 % and 6.7 ·C, respectively. Finally, the heat transfer performance was compared for the entire 3D structure PHP under uniform and non-uniform heating conditions. The non-uniform heating conditions of the PHP increased the thermal resistance and temperature of the evaporator under low heating rates while decreased them under high heating rates. [ABSTRACT FROM AUTHOR]

This study explores the flow properties of a couple stress fluid with the consideration of variable viscosity and a uniform transverse magnetic field. Under the effect of irreversible heat transfer, a steady fluid flow has taken place between two parallel inclined plates. The fluid flows due to gravity and the constant pressure gradient force. The plates are fixed and isothermal. The governing equations have been solved analytically for velocity and temperature fields. The total rate of heat flow and volume flow across the channel, skin friction, and Nusselt number at both plates are calculated and represent the impacts of relevant parameters through tables and graphs. The findings show that velocity, temperature, and the total rate of heat flow across the channel are enhanced by increasing the couple stress parameter and the viscosity variation parameter, while increasing the values of the Hartmann number reduces them. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Numerical study on the heat transfer characteristics of three-dimensional pulsating heat pipe" published in the Journal of Mechanical Science & Technology. The correction addresses an error in the original article regarding the acknowledgment section. The correction states that the work was supported by the Korea Maritime And Ocean University Research Fund in 2021 and the National Research Foundation of Korea. The correction notice is published by The Korean Society of Mechanical Engineers and Springer-Verlag GmbH Germany. [Extracted from the article]

• Performance characteristics of the LM cycle analyzed for domestic refrigerator. • Influence of the geometry of heat exchanger on LM cycle performance is studied. • R600/R290 mixture with 0.4 mass fraction was ideally validated experimentally. • LM cycle with the novel heat exchanger demonstrated enhanced energy efficiency. This study evaluates the performance enhancement of the Lorenz–Meutzner (LM) cycle with zeotropic mixtures of multiple refrigerants using a numerical simulation model. The computational simulation includes a heat exchanger model developed for predicting the air outlet temperature accurately. The predicted results are validated against experimental gliding temperature with varying mass fractions of different zeotropic mixture combinations. The R600/R290 mixture demonstrates the best performance characteristics. Various design changes of the heat exchanger are adopted to enhance the energy efficiency of the LM cycle. Counterflow configuration is found to be superior to the parallel configuration, particularly in the LM cycle, owing to the gliding temperature difference of zeotropic mixtures. Multiple refrigerant flow paths decrease the air outlet temperature further and prove to be more effective than the single flow path design. Based on careful investigation of the geometrical effect of heat exchangers on the LM cycle, a novel design of the heat exchanger is proposed, and its overall performance in the LM cycle is evaluated. The novel design of the heat exchanger indicates the largest air temperature difference, leading to the highest coefficient of performance (system energy efficiency) of the LM cycle compared with the baseline cycle with R600a. [ABSTRACT FROM AUTHOR]