This paper was concerned with an experimental study of parabolic trough collector’s with its sun tracking system designed and manufactured. To facilitate rapid diffusion and widespread use of solar energy, the systems should also be easy to install, operate and maintain. In order to improve the performance of solar concentrator, different geometries and different types of reflectors were evaluated with respect to their optical and energy conversion efficiency. To assure good performance and long technical lifetime of a concentrating system, the solar reflectance of the reflectors must be high and long term stable. Therefore, different types of reflector materials and absorbing materials were analyzed in this work; also the optical properties and degradation of the reflecting surfaces were assessed. During the research, focus has shifted from evaluation of the performance of concentrating solar collector to analysis of the optical properties of reflector and absorbing materials. The shift of focus was motivated by the need to assess long term system performance and possibilities of optimizing the optical efficiency or reducing costs by using new types of reflector materials and absorbing materials. For the design of the SPTC frame, a finite element model had been developed and used to check the capability of the structure to absorb torsion and bending forces, under dead and wind loads. The SPTC was fabricated in local workshops and the sun tracking system was assembled using electric and electronic components in the market, while the mechanical components making up the driving system were procured from the second hand market. The fabricated SPTC and its tracking system were tested outdoors in the campus under dry and wet weather. The experimental results obtained have shown that the obtained characteristic curve of the tested Aluminium collector is considerably lower than that of a mirror collector which can be attributed to the higher thermal losses for the lack of the evacuated glass envelope around the absorbing tube, the end losses of the collector and the inaccuracy in tracking the sun. However, the mirror collector efficiency is about 8% higher than that of Aluminium under dry weather condition, which is fairly acceptable, considering that it was the first attempt to manufacture such mirror collector locally. Thus, the overall aim of the INTERNATIONAL JOURNAL OF RESEARCH IN AERONAUTICAL AND MECHANICAL ENGINEERING Vol.1 Issue.4,August 2013. Pgs: 36-55 Pradeep Kumar K V, Srinath T, Venkatesh Reddy 38 work presented in this research was to investigate the possibilities to increase the efficiency of the solar energy systems, and thereby reducing the cost of the electricity or heat that was produced. Attention was also given to the long term durability and robustness of the system. The basic hypothesis was that the use of durable, light weight, low cost reflectors for increasing the concentrator efficiency

Optical imaging telescopes for space applications are typically designed and built to perform at their diffractionlimited performance, where-in their near theoretical limit of performance to be achieved. To obtain such performance, the mirrors front surfaces of the telescopes are typically fabricated and characterized to a surface accuracy λ/60 RMS and λ/10 PTV (where λ = 632.8 nm). Further, typical pointing and geometrical positioning accuracies of different optical elements in the telescope (such as primary & secondary mirror) are required to be controlled to less than 5 arc seconds and 10 microns respectively. The stability of the above performance for given operational and survival conditions is also very critical. The loads that influence the stability of performance of the system may be manufacturing process of each mirror & their mounts, assembly and interface loads, static pre-loads, dynamic launch loads, gravity release effects, on-orbit thermal and other environmental loads. During fabrication and testing of mirror performance on ground, the gravity induced self weight deformations becomes very critical. If the mirror are very large in size and are light weighted, the self weight deflections due to gravity becomes very significant and gravity release support systems thus become very essential. When the mirror is tested with mirror axis in horizontal orientation, the gravity induced self weight deformations will be quite different from that of Whiffle Tree mount deflections with mirror axis in vertical orientation due to different stiffness characteristics of the Light weight mirror in two different orientations and support conditions. To test such a large light weight mirror with mirror axis in horizontal orientation, special mounting techniques such as 2-axis / 3-axis Gimbal mounts or strap mounts are used to provide minimal gravity induced deflections. Thus, the Scope was to design, and analyze a semi-kinematic three axis Gimbal mount for testing a typical 1200 mm diameter light weight annular mirror with mirror optical axis in horizontal direction and the gravity vector is perpendicular to it. To carryout testing and characterization of such large size mirror in the above configuration, the proposed semi-kinematic mount, when realized shall provide minimal gravity induced deflections.

The function of stabilizer bars in motor vehicles is to reduce the body roll during cornering. This project looks into the performance of stabilizer bar with respect to their stress variations at corner bends and weight optimization. The focus is on the stress concentration at the corner bends of a stabilizer bar, that is designed for an automotive vehicle, which is reduced by optimizing the shape of the critical regions in two types of stabilizer bars, one is solid and other is hollow. In order to do this, parameters which constitute the geometry of the stress concentrated regions are determined. The effect of these parameters on stress concentration is evaluated by using Design of Experiments (DOE) approach and parametric correlations. Possible design options and their corresponding mass and maximum equivalent stress values are obtained by using Finite Element Analysis. The results are assessed by means of response surfaces generated by FEA software. FE analyses showed that it is possible to decrease the maximum equivalent stress at the critical regions for solid and hollow stabilizer bar by 11% and 12% respectively with a mass increase of 3.75% and 3.45% respectively. Transition form that gives optimum stress concentration is determined.