Cesaro fins parametric optimization for enhancement in the solidification performance of a latent heat storage system with combined fins, foam, and nanoparticle

The use of Phase Change Materials (PCMs) for latent thermal energy storage enhances the availability of solar energy. PCMs can store a large amount of energy in a small volume using almost entirely isothermal processes. Despite this, the poor thermal conductivity of PCMs is a significant disadvantage of current PCMs, severely limiting their energy storage capabilities. As a result, the solidification/melting rates are reduced to an unacceptable level, and the system reaction time is increased unreasonably. By combining the novel fin arrangement, nanoparticles, and metal foam, the current study improved the solidification rate of the PCM in the Latent Heat Thermal Energy Storage System (LHTESS). LHTESS was numerically evaluated in ANSYS Fluent 18.1 using a solidification and melting model. The addition of cesaro fins, nanoparticles, and metal foam significantly improved PCM solidification in the LHTESS. PCM solidification time was reduced by 42.42% and 39.39% in Type-3 and Type-5 fin configurations, respectively, when compared to Type-4 fin configuration. Furthermore, a temperature difference of 27 K between the Heat Thermal Fluid (HTF) and the PCM ensures the best solidification performance. By incorporating nanoparticles into PCM and metal foam, the solidification time is reduced by 73.68%. Depending on the foam structure and volume fraction of the nanoparticles, dispersing nanoparticles in PCM with metal foam saves up to 75% of the time

3D printed functionally graded foams response under transverse load

The applications of 3D printing are rapidly increasing in aerospace and naval applications. Nonetheless, 3D printing (3DP) of graded foams exhibiting property variation along the thickness direction is yet to be explored. In the current work, the different volume fractions of hollow glass micro balloon (GMB) reinforced high-density polyethylene (HDPE) composite based graded foams are 3D printed using the fused deposition modelling (FDM) technique. The bonding between successive layers and porosity distribution of these graded configurations are studied using micro-CT scan. Further, the 3D Printed functionally graded foams (FGFs) are tested for flexural response, and results are compared with numerical values. The micro-CT results showed delamination absence between the layers. In neat HDPE layers, porosity is not evident, while minor porosity creeps in the layers having the highest GMB content. Experimental results of the flexural test showed that the graded sandwiches exhibited better strength than the graded core alone. Compared to neat HDPE, the modulus of FGF-2 (H20–H40–H60) increased by 33.83%, implying better mechanical stiffness. Among all the FGFs, FGF-2 exhibited a better specific modulus. A comparative study of experimental and numerical results showed a slight deviation due to neglecting the induced porosity

Dynamic investigation of 650 W roof-top horizontal wind turbine rotor system supported by radial permanent magnet bearings

AbstractThe present work focuses on the rotor dynamic properties of a 650 W roof-top horizontal axis windturbine (HAWT) rotor supported by radial permanent magnet bearings (PMBs). Radial PMBs were designed and optimized concerning the rotor of a wind turbine for maximum stiffness. Initially, a generalized design and optimization process for multi-ring radial PMBs (MrRPMBs) with a radial air gap is presented to get the maximized force and stiffness per magnet volume. The proposed mathematical model is validated using the Finite Element (FE) analysis tool Ansys for chosen rotor dimensions. Then, the same optimization technique was extended for HAWT rotor bearings to extract the optimized multi-ring radial bearing parameters. The dynamic investigation is performed to study the effect of bearing parameters on the rotor-bearing modal frequency and dynamic amplitude of a rotor. Firstly, the dynamic investigation was performed for the conventional deep groove ball bearings (DGBs) supported rotor, considering the effect of bearing span length. Secondly, the dynamic response was analyzed for the rotor system through a hybrid bearing set (HBS) by replacing DGB with PMB. Finally, DGBs are completely replaced by radial PMBs. FEanalysis was performed using the Ansys workbench rotor dynamic tool for all the bearing combinations