chlodzenie-i-ogrzewanie: Heat transfer

Evidence: 100 • authority: 72

Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy (heat) between physical systems. Heat transfer is classified into various mechanisms, such as thermal conduction, thermal convection, thermal radiation, transfer of energy by phase changes, and evaporative cooling. Engineers also consider the transfer of mass of differing chemical species (mass transfer in the form of advection), either cold or hot, to achieve heat transfer. While these mechanisms have distinct characteristics, they often occur simultaneously in the same system. Heat conduction, also called diffusion, is the direct microscopic exchanges of kinet…

Evidence: 79 • authority: 72

Thermal engineering, sometimes known as applied thermodynamics and heat transfer (ATHT), is a specialized sub-discipline of mechanical engineering that focuses on the storage, transfer, and conversion of heat energy within or between thermal systems. Thermal engineers must apply the laws of thermodynamics, fluid mechanics, and heat transfer to design useful systems that generally involve either heat engines or heat exchangers. Thermal engineering is an essential discipline in many modern industries ranging from power plants to aerospace to computer design.

Evidence: 72 • authority: 92

Computational analysis of radiative heat transfer and free convective flow over a vertical wavy surface with Lorentz forces.. In several engineering systems, wavy surfaces are utilized to enhance thermal distribution such as heat exchangers and aerodynamics and drag control. However, when radiative heat transfer, heat generation and magnetic fields are considered, velocity and thermal distribution become more difficult, making it significant to understand their combined influences for improved heat transfer. Therefore, this problem focuses on the flow rate, isotherms, streamlines and thermal distribution of the hydromagnetic fluid flow over a wavy surface subjected to a constant heat flux w…

Evidence: 66 • authority: 92

Irreversibility analysis in stagnation-point flow of Casson bioconvective hybrid nanofluid under chemical reaction and stratification effects.. Entropy generation (EG) in hybrid nanofluid flows (HNFs) plays a crucial role in determining the efficiency and performance of thermal systems. It serves as a measure of irreversibility within these complex fluid flows, which directly impacts energy transfer and thermal conductivity. By analyzing EG, we can assess how effectively HNFs minimize energy losses, ultimately leading to improved overall efficiency in thermal management systems. The present study focuses on the analysis of heat transfer and EG in stratified bioconvective and magnetohydrodyn…

Evidence: 59 • authority: 92

Thermal Performance of ternary hybrid nanofluid with activation energy and surface tension gradient using HCM and YOM models.. This study inspects the Darcy Forchheimer flow of MHD trihybrid nanofluid with heat generation is briefly examined using the expanded model, also known as the YOM (Yamada-Ota model) and HCM (Hamilton Crosser model). The momentum equation includes the Darcy Forchheimer permeable medium. The importance of viscous dissipation and Joule heating are examined. Accurate prediction of thermal processes is a major concern for the community of energy researchers as well as for those conducting research on heat transport. Using a basic mathematical model as a sample example, t…

Evidence: 59 • authority: 72

A plate heat exchanger is a type of heat exchanger that uses metal plates to transfer heat between two fluids. This has a major advantage over a conventional heat exchanger in that the fluids are exposed to a much larger surface area because the fluids are spread out over the plates. This facilitates the transfer of heat, and greatly increases the speed of the temperature change. They are generally considered easier to clean and maintain compared to Shell and tube type heat exchangers. Plate heat exchangers are now common and very small brazed versions are used in the hot-water sections of millions of combination boilers. The high heat transfer efficiency for such a small physical size has…

Evidence: 59 • authority: 92

Semi-analytical analysis of transport mechanism in hybrid nanomaterial dynamics with oxytactic microbes using Xue model.. This study presents a comparative semi-analytical examination of Marangoni-driven mixed convective flow of a hybrid nanofluid containing oxytactic microbes over three different vertical geometries: cone, wedge and plate. The model integrates thermal radiation, viscous dissipation, Dufour-Soret effects, cross-diffusion effects, and magnetohydrodynamics within a single computational framework. The Xue thermal conductivity model characterizes the hybrid nanofluid's thermophysical properties with two different NPs dispersed in the base fluid. Results demonstrate that the Mar…

Evidence: 52 • authority: 92

A gas-pressurized coaxial tubular flow-loop apparatus for module-scale barocaloric heat transfer measurements.. Barocaloric materials offer a promising route toward solid-state cooling and pressure-tunable thermal energy storage, but most experimental studies rely on small-sample high-pressure calorimetry that does not capture heat transfer behavior at practical module scales. Here, we present a gas-pressurized module-scale barocaloric heat-transfer apparatus that represents the first reported module-level implementation of gas-mediated hydrostatic actuation. The apparatus uses a gas-mediated hydrostatic pressure system to actuate a gram-scale active material bed while a separate liquid flo…

Evidence: 52 • authority: 72

In thermodynamics, heat is defined as energy in transfer between a body and its surroundings, other than through thermodynamic work or through transfer of matter. Rather than by mechanical or other effects in the surroundings, thermodynamic work is defined through changes in the system's macroscopic state variables, in conjugate pairs such as pressure and volume, or magnetisation and magnetic field strength. The thermodynamic definition of heat is by exclusion of other defined modes of transfer in order to ensure a strict logical distinction. In the process of transfer, heat is not necessarily conserved, but can be generated (though not destroyed) by friction. In thermodynamics, temperature…

Evidence: 45 • authority: 80

5579652 Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

Evidence: 45 • authority: 92

Heat Transfer Enhancement in a Shell-and-Tube Type of Heat Exchanger Using Al<sub>2</sub>O<sub>3</sub>/Water Nanofluid.. Shell-and-tube heat exchangers are widely used in industrial processes, but improving the shell-side heat transfer without causing excessive pressure losses remains a major engineering challenge. Numerical simulations provide an efficient approach for evaluating thermohydraulic enhancement techniques while reducing experimental costs. The present study evaluates the heat transfer in a shell-and-tube heat exchanger using computational fluid dynamics by means of ANSYS Fluent software. Unlike previous numerical studies that mainly focused on thermal e…

Evidence: 45 • authority: 92

AlSi10Mg Heat Sinks for Passive Cooling: Convective-Radiative Performance of Finned and Triply Periodic Minimal Surface Designs via Laser Powder Bed Fusion.. Increasing power densities in electronic systems require efficient passive thermal-management solutions. This study numerically compares five DMLS-compatible AlSi10Mg heat-sink architectures: perforated planar-fin, curved radial-fin, Schwarz P, BCC diamond and gyroid designs. Conjugate heat-transfer simulations incorporating conduction, natural convection and surface radiation were performed under an identical 18 W thermal load. Performance was evaluated using surface temperature, thermal resistance, temperature uniformity and convecti…