Abstract-Design, simulation, and manufacturing process of an integrated thermal photovoltaic closed parabolic collector (ITPVCPC) using composite material is presented in this paper. The design includes two flanges for supporting photovoltaic panels. Two cases of troughs were designed and studied, one with glass cover over the aperture area and another without it in order to investigate the structure rigidity and solar ray collection in the absorber tube. Three-dimensional modelling and structural finite element analysis (FEA) based simulation was done for the design. In the simulation, the ITPVCPC structure was subjected to the upper limits of wind pressure and temperature-rise loadings similar to the real working conditions. Optical analysis was done for the trough to study the effect of structure deformation on solar ray collection. The glass covered ITPVCPC showed higher structure deformation than the one without glass. Glass fiber with polyester resin was used in the manufacture of ITPVCPC for its low price compared to other composite materials. The study shows that glass fiber (with polyester matrix) is an ideal composite material for ITPVCPC for its high rigidity, low cost, and ease of manufacture. This design is successfully implemented and is the source of thermal and electrical power for a solar desalination system installed in Jeddah, Saudi Arabia. Keywords: Finite element analysis (FEA), concentrating solar power (CSP), hand-layup method, glass fiber reinforced polymer (GFRP) I.INTRODUCTION Fossil fuels such as petroleum oil, coal and natural gas are used as a primary energy source in developed nations. These carbon rich fuels release CO2 to the environment which has a negative effect on the atmosphere. It alters the radiation-balance of the earth and promotes global warming [1]. This has forced the consumers to think of alternate sources which would be cheap at least in the long run. Due to awareness of pollution and economics of fuel, the focus is now shifted to solar and other clean energy sources. Parabolic trough technology is currently the lowest-cost concentrating solar power (CSP) technology for electricity production [2]. Parabolic trough collector (PTC) uses a highly reflective surface to focus incident solar rays on a heat collector element (HCE) also called receiver tube. The receiver tube is placed at the point of convergence (focal point of parabola). The tube contains a working fluid that absorbs solar heat and gets heated up to temperatures of 350o C or more. It is enveloped by an evacuated (vacuumed) glass tube to reduce convective heat loss to the surrounding. The collector has a disadvantage of smaller angle of view. Therefore, to maximize the solar heat gain, a tracking mechanism is used to align it with respect to the changing position of the sun. Collector is being considered for a lot of applications like Enhanced Oil Recovery (EOR) [3], water disinfection in third world countries [4], desalination [5], refrigeration and cooling [6], heating applications [7] etc. Many innovativ...

Solar energy is becoming a promising source of heat and power for electrical generation and desalination plants. In this work, an integrated study of modeling, optimization, and experimental work is undertaken for a parabolic trough concentrator combined with a humidification and dehumidification desalination unit. The objective is to study the design performance and economic feasibility of a solar-driven desalination system. The design involves the circulation of a closed loop of synthetic blend motor oil in the concentrators and the desalination unit heat input section. The air circulation in the humidification and dehumidification unit operates in a closed loop, where the circulating water runs during the daytime and requires only makeup feed water to maintain the humidifier water level. Energy losses are reduced by minimizing the waste of treated streams. The process is environmentally friendly, since no significant chemical treatment is required. Design, construction, and operation are performed, and the system is analyzed at different circulating oil and air flow rates to obtain the optimum operating conditions. A case study in Saudi Arabia is carried out. The study reveals unit capability of producing 24.31 kg/day at a circulating air rate of 0.0631 kg/s and oil circulation rate of 0.0983 kg/s. The tradeoff between productivity, gain output ratio, and production cost revealed a unit cost of 12.54 US$/m3. The impact of the circulating water temperature has been tracked and shown to positively influence the process productivity. At a high productivity rate, the humidifier efficiency was found to be 69.1%, and the thermal efficiency was determined to be 82.94%. The efficiency of the parabolic trough collectors improved with the closed loop oil circulation, and the highest performance was achieved from noon until 14:00 p.m.

A modified semi-empirical formula that relates the maximum range of the positron to the strength of different magnetic field strengths is developed via Monte Carlo simulation. The formula is derived as an extension to the existing formula of no magnetic field. COMSOL Multiphysics is used to simulate the different physics, including electromagnetic physics and charged particle tracking physics. The Monte Carlo simulation technique by COMSOL is employed to study the effect of magnetic field strength on the positron range PET/MRI scan of the head's tumor. The magnetic field varies in the range 1-10 Tesla. The simulation code using positron emission is conducted by the Monte Carlo method. Simulation results show that changing the magnetic field affects the particle trajectory and hence the maximum positron range. The elliptic trajectory causes a reduction in displacement between the original location of emission and the location of annihilation, which permits an increased photon emission per unit volume of the tumor and hence a better image resolution. The main contribution of the paper is the formulation of a new semi-empirical relation taking into account the presence of a magnetic field by simulating different particle trajectories for the different magnetic field strengths.

This paper presents three-dimensional numerical simulation of thermomechanical constitutive model for shape memory polymers. Shape memory polymers (SMPs) are a class of smart materials with high potential for application to automotive, aerostructures, and medical devices, which can benefit from its intrinsic shape changing properties. In particular, looking at its application to aerospace substructure such as morphing wings, thermomechanical behavior of the SMPs needs to be well established and predicted. In order to predict the thermomechanical behavior of SMPs structures, a one-dimensional rheological thermomechanical constitutive model was adopted and a numerical simulation of this model was developed using a commercial finite element analysis package ABAQUS. The particular one-dimensional model was selected due to its potential to represent the key material behaviors of SMP with a relatively low number of required material constants, which is practical for engineering industrial applications. The model was expanded to a three-dimensional isotropic model and then incorporated into the finite element method by means of an ABAQUS user-defined subroutine (UMAT). The methods of three-dimensional expansion and numerical implementation are presented in this work. A time evolution of the analysis was conducted by making use of the backward difference method, which was applied to all quantities within the model including the material properties. A comparison of the numerical simulation results was carried out with the available experimental data. Numerical simulation results clearly exhibit the thermomechanical properties of the material, which include shape fixity, shape recovery, and recovery stress. Finally, a preliminary set of predictions for an unmanned aerial vehicle (UAV) morphing wing skin are also presented.

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