Abstract

Three phase fluidization is an effective technique to achieve sufficient mixing of phases, with better mass and heat transfer rates. The economical design and operation of the fluidized bed needs to study the hydrodynamic characteristics for better performance. The present work is an experimental investigation on the hydrodynamic behavior of a co-current three phase fluidized bed with liquid as a continuous phase in a 54 mm id Perspex (Acrylic column) with particle size of 4.38, 3.89 and 1.854 mm glass beads. Based on the experimental work, the various parameters such as pressure drop, porosity, gas and liquid holdups were studied and the observed data was reported.

Abstract

This research is an exploration of the essential phenomena that determine the response of silicon carbide-reinforced aluminium composite materials to thermal cycling between cryogenic and ambient temperatures. This analysis began with an general approach that investigated the role of production, processing, and machining of composite materials along with a study of their mechanical behaviour at cryogenic temperatures. Composite specimens were subject to electro-discharge machining to develop mathematical models for the prediction of machining parameters such as metal removal rate, tool-wear rate and surface roughness.  A five level factorial design was selected for the purpose of experimentation and mathematical models were developed using the experimental design software application DOE-PC IV.  An analysis of variance technique was applied in order to calculate the regression coefficients and to test the significance of the models developed.  This approach provided an understanding of how temperature and volume as a percentage of SiC influence composite machining behaviour. The values of hardness, wear resistance and tensile strength properties are high for cryo-treated specimens and these values reduce proportionally with increases in temperature.  Such properties also increase with increasing the percentage volume composition of SiC reinforcements. The microstructure of the wear specimens show the worn out layers and the the grooves formed in their debris.  The  cryo-treated and the higher reinforced specimens (by percentage volume) exhibit lesser material removal and tool wear which increases with increase in temperature. There is also observed a relatively higher surface roughness when there is greater material removal.

Abstract

Urea was grown from aqueous solutions with the organic additives by the slow evaporation method for obtaining an improved crystal size and enhanced nonlinear properties. The new material obtained was nonhygroscopic with remarkable morphological change compared to pure urea. The influence of the organic additives on the optical, structural, thermal and mechanical properties of urea were studied by UV in visible region, Fourier transform infra red spectroscopy, X-ray diffraction and  microhardness studies by Vicker’s hardness test. The second order nonlinear optical property was examined by Kurtz powder technique and is measured using Nd:YAG laser at 1064 nm with a beam energy of 3.2 mJ/pulse. This material grown as a single crystal has a widespread application in the field of optoelectronics engineering and technology.

Abstract

Alternative-fuelled engines should be designed to counter the faster depletion of fossil fuels. Also, it becomes essential that eco-friendly technologies be used everywhere to prevent degradation that is caused due to the combustion of petroleum-based fuels. Hydrogen with low spark-energy requirement, wide flammability range and high burning velocity is an important candidate for being used as a fuel in Spark Ignition engines. It also offers almost CO, CO₂ and HC free combustion and lean operation resulting in lower NO_x emissions. Present work aims at reducing the emissions and specific fuel consumption by supplementing the hydrogen in different amounts along with gasoline and observing the performance and emission characteristics of a two-stroke engine. It is found that about 25% and 75% reductions are possible in hydrocarbon and CO emissions when compared with gasoline. Also, comparison of the performance of the engine with and without hydrogen is done.

Abstract

Electro oxidation processes are developed throughout the world for ambient temperature destruction of organic wastes. Several of these processes are based on Mediated Electrochemical Oxidation (MEO). This article presents the experimental results of electro chemical study based on MEO process conducted for synthetic organic ion exchange resin materials. Investigation was carried out using the traditional noble metal oxide coated anode, RuO₂/Ti and the mediators used for the experiment were in situ generated OCl- ion and the Fenton’s reagent (Fe₂+/Fe₃+ + H₂O₂),OHo.

The experiment was carried out in constant stirring batch reactor with current densities 1.25, 2.5, 3.75, 5.00 A/dm² for various flow rates 20, 40, 60, 80, 100 L/H. The results of the experiments shows that the best effect of TOC reduction was found to occur at 3.75 A/dm² in batch setup with flow rate of 20 L/H.

Abstract

The lean combustion of an SI engine has been recognized as one of the most promising method of further improvement of fuel economy. According to automotive pollution point of view, exhaust emissions as NOx, CO &HC are reduced because of abundance of oxygen and lowering of peak temperature. The present study was aimed at ascertaining the benefits of employing catalysts in the combustion chamber of an SI engine. In our study we have tried to combine the concept of catalytic coating and lean burn to improve performance of an SI engine. The literature study has revealed that there is enormous potential for catalytic coatings in the automotive engines. We have chosen 100CC YAMAHA RX100 engine in our study because these two stroke engines are one of the greatest monsters that could demolish the atmosphere. In our investigation we have used a silver catalyst and nickel catalyst in 100CC engine. Experiments were conducted using multi utility roller test bench and exhaust analyzer. As the result of coating of catalysts such as nickel and silver the mileage of the vehicle has been increased by nearly 10%.

Abstract

The work reported here concerns the design and evaluation of a fixture used in vibrational analysis of a fluid filled manifold tract component used for automotive applications. The manifold was subject to physical vibration in order to simulate its location and environment in an automobile. The fixture used was a bracket assembly used for the location and securing of the manifold tract component to a dynamic shaker-rig.

Abstract

Most experts believe that an energy system based on fossil fuels cannot be sustained for another century; the reason is that they are going to be exhausted soon. Even if additional reserves are discovered, many scientists say that continued reliance on fossil fuels as a primary energy source over the coming decades could release into the atmosphere billions of metric tons of carbon dioxide and other heat-trapping gases. For all these reasons there is need to rely on Alternative Fuel Technology. It is estimated to increase the use of alternative and reproducible fuels to 30% and 50% of fuel requirement by the years 2030 and 2050 respectively. At present, biodiesel is commercially produced from the vegetable oils by esterification process. This process is not suitable for production of biodiesel from many vegetable oils because of their high acid value. Hence supercharging is done by means of an electrically driven two stage reciprocating air compressor and Straight Rice bran oil is implemented as fuel by means of two tank SVO system with heating arrangement. In the present investigation, tests were carried out to determine the performance and the emission characteristics of the CI engine under Natural aspirated and supercharged conditions with petroleum Diesel and Pure Rice bran oil and the results were compared. . BSFC is increased with supercharging pressure in both diesel and RBO operations and BSFC is more in RBO operation than in Diesel operation. The CO emissions tend to increase with supercharging pressure in both diesel and RBO operations. Unburnt HC emissions are lesser in RBO operation than in diesel operation. CO₂ levels tend to increase with supercharging pressure in both diesel and RBO operations with loads near to rated load of the engine. The NO_x emissions are lowered with RBO than diesel with supercharging.

Abstract

Functionally graded materials (FGMs) are designed to achieve a functional performance with gradually variable properties in one or more directions. In this research study, a functionally graded cantilever beam was subjected to bending moment at the free end, and then investigated. The beam properties were reviewed and varied symmetrically throughout the thickness in terms of volume fraction of material constituents. The variation in stress and deflection for different functional gradients was analyzed by using the finite element analysis package - ANSYS 10.0. The objective of this work is to investigate, how different grading configurations of beam will affect its bending stress and deflection due to applied bending moment and the effectiveness of FGMs beams in structural applications. The results show that the use of FGMs are capable of and advantageous in reducing the deflection and strain that may arise in structural beams.

Abstract

A parabolic concentrating type dish solar cooker of width 180cm and focal length of 90 cm is deduced from unused perforated aluminium dish antenna. The perforated surface is pasted with aluminium foil for good reflection. Its performance as a concentrating type dish solar cooker is studied with black painted aluminium vessel as absorber.  The time consumption by this type of dish solar cooker is comparable with the conventional solar concentrators made by experimentalists. Various food items are cooked in this type of dish solar cooker. The results are quite encouraging.