ABSTRACT In order to have best performance of leaf spring, a study was conducted to replace the conventional steel leaf spring that used in vehicle by composite materials. This thesis focused on describe about design and analysis of hybrid composite leaf spring. A rear leaf spring for a "Toyota" is regarded for this purpose, and three materials are employed to fabricate the leaf springs. The matrix material was epoxy, while the reinforced materials were E-glass and carbon. Composite materials have a good corrosion resistance, a high strength to weight ratio, and high elastic strain energy storage capacity. So aim of this research is to investigate the structural properties of a hybrid leaf spring which made of (95% Epoxy with 5% carbon), (95% Epoxy with 5%glass fiber), and (95% Epoxy with 5% of hybrid composite 2.5% of carbon and 2.5% of glass fiber). In this study, Hand Lay-up technique was used in the fabrication of leaf spring due to its advantages (low cost tooling and simplest method) over the other methods. The effectiveness of the proposed composite leaf spring was evaluated by implementing the mechanical tests, which were Tensile, Impact, Hardness, Fatigue, Damping and Flexural. The experimental results recorded an improvement in the mechanical properties when the reinforcing fibers are used as well as the best results were obtained by hybrid reinforcement. Finite Element method was employed based on ANSYS software to simulate the leaf spring part. The linear isotropic model was chosen to determine stresses, deformations, and fatigue life when an internal static load is applied. Finally, the results proved that the hybrid composite materials have the ability to carry the load-applied leaf spring without failure and with minimum deflection and long fatigue life

Abstract

Abstract Promotion of renewable energy sources like solar, wind for responding to increasing global energy demand requires efficient means to correct their intermittent nature. Latent Heat Thermal Storage (LHTS) based on Phase Change materials (PCMs) offers a promising solution for efficient utilization of intermittent energy from renewable sources. However, the primary limitation is the poor thermal conductivity of PCMs, which requires employing of thermal performance enhancement techniques. To overcome this deficit, an open-cell structure with a high porosity copper foam is employed to enhance the overall thermal conductivity of PCM, leading to improved heat transfer exchange, and hence, promoting the PCM charging rates. This enhancement technique has been utilized to improve the LHTS performance having a shell and tube structure filled with PCM, where a copper foam is compounded to the PCM. For this purpose, an experimental setup was fabricated to examine the heat transfer performance on two shell-and-tube LHTS configurations: pure PCMLHTS (pure LHTS) and PCM-copper-foam composite (foamed LHTS). The experimental observation is supported by computational models that allow the investigation of heat transfer performance, and track the phase change interface during melting. The numerical simulation was done using ANSYS fluent (version 19) CFD. The thermal behavior of LHTS configurations was investigated in terms of temporal evolution of PCM temperature in different axial and radial directions, PCM average liquid fraction, and thermal storage orientation at various inlet HTF temperatures. The heat transfer fluid (HTF) was flowing through the heat exchanger tube at different inlet temperature of 70 oC, 75 oC, and 80 oC. Experimental observations showed that the foamed LHTS configuration has a better performance than that of pure LHTS, while the variation of HTF was found to have a major impact on the heat transfer rate with both configurations. As a result, the reduction in total charging time, which ii from 360 min to 65 min is clearly observed because of the foam. The saving in total melting time of simple LHTS was about 82% with provision of copper foam. The saving in total melting time of foamed LHTS arrange vertically was about 34% for an HTF temperature increase from 70 oC to 80 oC. The saving in phase change time for horizontal foamed LHTS was about 19% higher than vertical LHTS at completed melting process. Therefore, the results suggest that horizontal LHTS is preferable for full load conditions rather than vertical LHTS. It is also observed that the highest rate of stored energy can be obtained at a higher HTF temperature for both LHTS orientations. The role of adding copper foam on the development of phase change cycle was confirmed by visual observation