The heat storage coefficient deals with the thermal behaviour of a substance. It is calculated from the thermal conductivity and the volumetric heat capacity. An experimental investigation has been carried out to understand the behaviour of the heat storage coefficient of different materials at different gas pressures. The purpose of this article is to investigate the capability of multiphase systems to insulate heat at both normal and interstitial gas pressures. The study is important because of its usefulness in selecting materials mainly for the design of storage tanks, pipe lines, construction of buildings, fabrication of walls of furnaces and the design of solar storage tanks.
A. P. Senthil Kumar*, S. Janaki, N. Jagadeesh, T. Sakthivel, R. Selladurai.
In this article, the 3-Dimensional numerical model has been developed for estimating effective thermal conductivity of porous system based on unit cell approach. The inherent 3-D problem is modeled using Finite Element Analysis for various inclusions (square, circular, hexagon and octagon). The model is tested with at different composition of solid to fluid fractions and solid to fluid conductivities. Comparison has been carried out for 2-Dimensioanl and 3-Dimensional effect for various inclusions for estimating the effective thermal conductivity of porous materials. The results shows that for higher concentration and conductivity ratio, the model with varying cross section estimates the effective thermal conductivity of two phase materials with higher accuracy.
Senthil Kumar A. P*, S. Janaki, N. Jagadeesh, R. Selladurai, T. Sakthivel.
This paper describes the novel spatial three-dof 3-SUR1-RU Parallel Platform Robot. This robot is under development at Ohio University to serve as the active orienting device for aerodynamic testing of unmanned aerial vehicles (UAV) with up to 3m wingspan. The UAV will be tested on a Wind mobile which is a ground vehicle that is driven with the test article on an instrumented truss extended in the front in an undisturbed flow field. This system is an inexpensive substitute for a large-scale wind tunnel for measuring aerodynamic parameters of the UAV. The platform robot three-degrees-of-freedom (dof) are actively controlled by three servomotors mounted to the underside of the moving platform and there is a passive fourth middle leg with passive R-U joints for support. The inverse orientation kinematics (IOK) problem is formulated and solved analytically in this paper. Given the three desired Euler Angles, the three required actuator angles are found. Geometrically this analytical solution is equivalent to finding the intersection point of two circles on different planes, independently for each of the three platform robot legs. The analytical solution requires finding the roots of a quadratic polynomial. There are at most two real solutions per leg (elbow-up and elbow-down), leading to 23=8 overall solutions to the IOK problem, since there are three active legs. Examples are presented to demonstrate the new platform robot IOK solution algorithm.