Abstract: This study investigates the effect of n-heptane on cold flow properties of biodiesel blends, and the performance and emissions of a direct injection (DI) diesel engine with 5, 10 and 20 vol. % n-heptane with B5, B10, B20, B50 and B100. Fifteen fuels of H20, H10 and H5 series are tested and compared for performance and emissions under conditions of rated engine speed of 1800 rpm and different loading conditions for each fuel sample. The research results show that the blends up to B10 with 5%, 10% and 20% n-heptane have similar cloud points (CP) and pour points (PP). The brake specific fuel consumption (bsfc) increases with the increase of biodiesel in the blends at different load conditions. The engine emits lower carbon monoxide (CO) with higher amount of biodiesel and n-heptane in the blends. Peak value of hydrocarbon (HC) is noticed with B5 blends. Nitric oxide (NO) and oxides of nitrogen (NOx) emissions follow similar trends, which increases with the increase of biodiesel in the blends while less n-heptane in the blends.

Abstract: This paper describes the natural frequency analysis of strongly coupled vibration of a closed ends rigid cylindrical cavity containing liquid and gas which separated by a thin circular plate at their interface. A theoretical analysis method to compute the natural frequencies of the liquid-structure-gas coupled system were developed with assumptions is made with respect to the boundaries between the liquid, structure and gas. The theoretical natural frequencies of the complete coupled system were found to be in good agreement with the corresponding values obtained experimentally and from a commercial Finite Element Analysis (FEA) code.

Abstract: The current study focuses on application of numerical homogenization techniques to predict the effective electromechanical properties of the periodic transversely isotropic piezoelectric (PZT) cylindrical fiber composites. ANSYS® finite element package used to develop the different numerical representative volume element models of unidirectional periodic composites made of piezoelectric fibers surrounded by a soft non-piezoelectric polymeric matrix. The formulation of the boundary conditions receives remarkable interest to allow the simulation of all deformation modes coming up from mechanical or electrical loadings or any arbitrary combination of them. ANSYS Parametric Design Language (APDL) used to generate all required constraint equations. Effective electromechanical properties of unidirectional piezoelectric cylindrical fiber composites with hexagonal fiber arrangements calculated over a range of PZT fiber volume fractions. Furthermore, for verification the homogenized elastic, dielectric and piezoelectric properties compared to corresponding analytical, numerical and experimental results reported in the literatures, which demonstrate good correlations. The different representative volume element models developed using APDL scripts can provide a powerful tool for rapid calculation of effective piezocomposite properties. Moreover, it can be applied to composites with diverse inclusion geometries.

Abstract: Flat Plate Solar Water Heaters are extensively used all over the world to utilize the natural source of solar energy from sun. In order to utilize the solar energy during off sunshine hours it is inevitable to store and retain solar thermal energy as long as possible. For effective gain and retention of solar thermal energy a fins are provided. Depth of fins immersed in water, V-grooved and dimpled absorber surface in a solar thermal collector are important geometric parameters that influence the maximum temperature rise during peak solar irradiation and hence the losses. CFD studies show an improved heat transfer with increase in depth of fin.

Abstract: Flow velocity and pressure are two related phenomena in the flowing fluid in a pipe containing an orifice. In this study, the focus will be on the pressure which is known to researchers under variety of names such as pressure distribution, pressure fluctuation, static pressure, pressure loss, or line pressure. This pressure (not the dynamic pressure) is triggered by the disturbance of the flow passed the orifice as the flow contract spinning, rotation, and circulation through which the flow transiently causes pressure on the wall which increasingly becomes a real concern to the designers of piping circuit of nuclear plant, turbines, or, more importantly, the flow measurement. Navier-Stocks equations have been employed to describe the velocity, pressure, stress, vorticity, strain, and total deformation using commercial CFD code ANSYS for incompressible fluid. The pressure fluctuation in conjunction with flow velocity was studied at three aspect ratios of 0.2, 0.4, and 0.6 at Reynolds number of 10000, 20000, and 30000. The study shows a strong correlation between the flow velocity (directly related to Reynolds number) and both the pressure and the stress acting on the wall. The axial maximum magnitude of the velocity and pressure appear around the orifice plate and both diminish beyond that. Vorticity and flow velocity are well correlated and are in good agreement with previous studies. The maximum stress, strain, and total deformation have powerful effect on wall at aspect ratio of 0.2 while this effect is almost nullified when the aspect ratio is higher. The study adds to the body of knowledge better understanding to the effect of higher Reynolds numbers and higher aspect ratios.

Abstract: A Conceptual Design and Aerodynamic Study of Business Jet BWB Aircraft is carried out focusing on BWB Aerodynamics, including Wing Planform Configuration and profiles, and their relationship to the Design Requirements and Objectives. Possible Configuration Variants, Mission profile, Flight Envelope requirements, performance, stability, as well as the influence of propulsion configuration and noise considerations of BWB aircrafts are considered and elaborated. Parametric study performed on wing planform, thickness, and twist optimization, with design variables including overall span plus chord, sweep, thickness, and twist at several stations along the span of the wing prior to more structured optimization scheme. Considerations are also given to range, trim, structural design, maximum lift, stability, control power, weight and balance. A statistical study and review on prevailing market demand lead to the choice of a candidate of conventional Subsonic Business Jet, which will be used as a baseline for the aerodynamic and configuration conceptual design. The chosen business jet accommodates 10 passengers as a baseline. Some aerodynamic and performance improvement is then carried out through parametric study to arrive at the best solution meeting the design requirements and objectives.

Abstract: The zero energy building considered is a single storey building in Tiruchirappalli city retrofitted with various green features. This study investigated the effect of a suction opening orientation on the inclination of solar chimney, integrated into a one storey building. It was designed, manufactured and tested through selection of different suction openings for the entry of air including right, left, front, back, both right & left and both front & back sides at 900 and 500 angle of solar chimney. The obtained results are related to fluid flow temperature distribution along the chimney, mass flow rate and air change per hour.