Simulation and optimization of steady-state heat transfer property measurement platform

This paper studies the measurement technology of heat transfer coefficient of building envelope, explores the main factors affecting the measurement of heat transfer coefficient, uses ANSYS Icepak software to simulate the steady-state heat transfer property measurement platform model, and establishes the virtual prototype of the product. The product design based on Icepak replaces the test on the physical prototype with the simulation on the virtual prototype, We should reduce or even cancel the manufacturing of physical prototype, shorten the R & D process, and cut R & D costs with the improvement of design quality. Through the comparison and analysis with the experimental data of the offline detection platform, the feasibility of using Icepak to simulate the equipment is proved. The software is used to simulate the ther-mal environment in the hot box. Through comparison and analysis, the most uniform upper wi-nd steady-state thermal environment scheme is found.

Use of Nano Fluids in Nuclear Technology: A Review

Nuclear energy is the most important source to produce electricity. The production processes are very important for reducing risks and increasing the efficiency. Nano-fluids also have the potential to transfer heat with improved thermo-physical properties which can be applicable in many devices for better performance. Advancement in nanotechnology develops new fluids which transfer heat called nano-fluids. So, for heat exchange in the core of nuclear reactors, nano-fluids are used because of their unique heat transfer properties. For significant improvement in properties, the modest concentration of nano-particles is required. Recent research is more about behaviour of nano-fluids to utilize their unique properties. Heat transfer property is very important for industrial applications, nuclear reactors, transportation, and electronics and also in biomedicine. Nano-fluid acts like smart fluid, where heat transfer property can be controlled. This review establishes a focus on the wide range of recent and future uses about nano-fluids, related to their improved properties of heat transfer that may be controllable and other specific properties of nano- fluids.

Flow and Heat Transfer Property of Oldroyd-B-Fluid-Based Nanofluids Containing Cylindrical Particles in a Pipe

Flow and heat transfer property of Oldroyd-B-fluid-based nanofluids containing cylindrical particles are studied in a pipe with circular cross-section in the range of Reynolds number (Re) from 100 to 2000, Weissenberg number (We) from 0.1 to 2, particle aspect ratio (β) from 2 to 16 and particle volume concentration (Φ) from 0.1% to 2.5%. The motion equation of Oldroyd-B fluid with particles, the equation for probability density function of particle orientation and convection-diffusion equation for particles are solved numerically. The numerical method used in the simulation is validated by comparing with the available results. The effects of Re, We, β and Φ on the friction factor (f), Nusselt number (Nu) and ratio of energy performance evaluation criterion (PECt/PECf) for Oldroyd-B-fluid-based nanofluids to that for Oldroyd-B fluids are discussed. The results showed that the values of f and Nu of Oldroyd-B-fluid-based nanofluids are larger than that of water-based nanofluids and that of pure Oldroyd-B fluids. The values of f increase with increasing Re, We and Φ, but with decreasing β. The values of Nu and PECt/PECf are enhanced with increasing Re, We, β and Φ. The increase of f is larger than that of Nu at lower Re, but is less than that of Nu at higher Re. It is more effective to use Oldroyd-B-fluid-based nanofluids with cylindrical nanoparticles to improve the heat transfer at the conditions of higher Re, We, β and Φ. Finally, the correlation formula of PECt/PECf as a function of Re, We, β and Φ is derived.