Mechanical Engineering

The ever fast growing information technology is enabling a re-definition of the early stages of aircraft design which has been restricted to mostly statistical and empirical approaches because of lengthy and costly simulation times .The paper basically deals with designing a UAV by considering various parameters such as aspect ratio, taper ratio, power loading etc. During design, electronic components are to be considered and number of channels to be used is taken into account. Based on the above parameters a rough sketch of our aircraft is designed, later detailed calculations for each part of the aircraft is done keeping in mind of our objectives. In basic analysis, the main focus is on how various parameters such as lift, drag, co-efficient of lift v/s angle of attack etc behave on the wing. The basic analysis is performed using design foil software, analysis is done in order to check the theoretical calculated value matches with the nearest value obtained in the software and also to place the wing at desired angle of attack for the aircraft to achieve stable flight, it is also corrected for errors if any. Finally our own prototype manufactured is displayed & tested practically.

A compressor is the heart of vapour compressor system. The function of refrigerator compressor, being an integral part of the system, is related to relate to other components. Hence its capacity, life, breakdown, etc. are very much influenced by the performance of other components like condenser, evaporator, throttling device etc. in this present paper the reciprocating compressor is being replaced by a screw compressor. The performance analysis is conducted and further a comparison analysis is done. It has been found that the screw compressor with certain limitation is more effective and saves the power.

Thermal energy can be stored as latent heat in which energy is stored when a substance changes from one phase to another by either melting or freezing. Paraffin wax has been widely used for latent heat thermal energy storage system applications due to large latent heat and desirable thermal characteristics. Paraffin wax has lower heat transfer rates during melting/freezing processes due to its inherent low thermal conductivity. This paper reviews and summaries the recent experimental and theoretical works on the thermal conductivity enhancement of paraffin wax.

The experiment was conducted at the fields of Agriculture College-University of Baghdad Al- Jadiriyah in 2015 in sandy loam soil to evaluate using locally Ultrasonic device for determining the tillage appearance for different primary tillage equipment. New Holland" tractor was used in this study. Two levels of soil moisture included 18-20% and 14-16% and primary tillage implements included: disc plow , chisel plow and sweep plow were used . Soil surface roughness, number of clods with diameter larger than 10 cm , disturbed soil volume, bulk density, total porosity were measured. Split plot design under randomized complete block design (RCBD) with three replicates was used. The results were showed that the best soil surface roughness was obtained at the second moisture level, and higher porosity 53.89 % at the first moisture level and there were no significant differences for levels moisture in both the number of clods with diameter larger than 10cm , disturbed soil volume and bulk density. Sweep plow superior in obtained less soil surface roughness , less number of clods with diameter large than 10cm 10.00 clod / m2 and higher porosity 53.94 % compared with chisel plow and disc plow. Higher disturbed soil volume obtained at the chisel plow 1193.00 m3 / hr, while no significant differences in bulk density attributed by plows types. Sweep plow with second moisture level was the superior in obtained less soil surface roughness and less number of clods with diameter large than 10cm 9.33 clod / m2, and sweep plow with first moisture level obtained less bulk density 1.17 mg / cm3 , higher porosity 55.33% While higher disturbed soil volume 1202.00 m3 / hr. obtained in chisel plow with first moisture level treatment

The need for eco friendly alternatives to conventional cutting fluids arises because usage of conventional cutting fluids poses threat to ecology and health of workers. The present work focuses on performance of nano solid lubricant suspensions in vegetable oils in turning of AISI1040 steel in minimum quantity lubrication(MQL). Soyabean, canola and coconut oils are taken as base lubricants with suspensions of 100nm sized boric acid particles. These particles are characterized by X-Ray Diffraction (XRD) and particle size analyzer to confirm their purity and particle size. Variation of basic properties like thermal conductivity, specific heat and heat transfer coefficient are evaluated from empirical relations, to check the viability of nano lubricants in machining. Variation of cutting tool temperatures, average tool flank wear and surface roughness of the machined surface with cutting speed and feed are studied with the prepared nano lubricants. Results are encouraging and coconut oil seems to be more advantageous compared to other vegetable oils.

The numerical studies are performed to examine the Micropolar fluid flow past an infinite vertical plate. Finite difference technique is used as a tool for the numerical approach. The micropolar fluid behaviour on two- dimensional unsteady flow have been considered and its nonsimilar solution have been obtained. Nonsimilar equations of the corresponding momentum, angular momentum and continuity equations are derived by employing the usual transformation. The dimensionless nonsimilar equations for momentum, angular momentum and continuity equations are solved numerically by finite difference technique. The effects on the velocity, micro rotation and the spin gradient viscosity of the various important parameters entering into the problem separately are discussed with the help of graphs.

This paper presents a hybrid optimization approach for the determination of the optimum laser welding process parameters which minimize the weld bead width and maximize weld bead depth together in pulsed Nd:YAG laser welding of thin plates of SS 304 having thickness 2.9 mm. An exhaustive experimental study has been conducted with various process parameters like, pulse width, pulse height, stand-of distance, frequency, welding speed, gas flow angle and gas flow rate. Each of the parameters has three levels. Thus, an orthogonal array L18 has been adopted to accommodate all the above factors at their respective levels. The weld bead width and the weld bead depth are considered as process performances. A multi-response optimization has been carried out by using grey relational analysis (GRA). Also the significant process parameters have been found out for the above process optimization by performing an ANOVA.

The problem of robot selection plays an important key role concern to various fields of different applications since three decades. This problem has become more difficult in recent years due to increasing complexity of applications of the environment, features and specifications, and facilities offered by various manufactures. The primary objective of this paper is to select the suitable type of robot based on various factors such as type of application, payload, working environment, accuracy, lifespan, weight, purchasing cost etc. The selection procedure is developed for selection of particular type of robot based evaluating the various alternative selection factors using AHP technique and systems of equations of the matrices i.e. Eigen values and Eigen vectors. The ranking evolution will provide a good guidance for the robot selection to the end user. The concept of this work is an attempt has been made to create exhaustive database for identifying maximum possible number of attributes.

This paper outline is an experimental study to optimize process parameters of plasma arc cutting for stainless steel 420. Three process parameters were chosen these are cutting speed, cutting current and torch height. The experiments are conducted based on taguchi’s L9 OA. The objective of optimization is to attain minimum Ra and maximum MRR individually. Regression models for Ra and MRR are developed based on Regression analysis in Minitab 17 Software. The optimal settings is obtained for Ra and MRR by using Genetic algorithm optimization technique in MATLAB R2013a software.

Manufacturing industries aims at the reduction in usage of cutting fluids to combat Environmental and Ecological issues towards which new techniques are being explored. Hard turning with minimum quantity lubrication is one such technique which can abate the pollution problems associated with the cutting fluids. The present paper deals with the experimental investigation in turning of hardened AISI D3 steel with CVD coated indexable inserts under minimum quantity lubrication using vegetable oils as cutting fluids. An orthogonal array, analysis of variance(ANOVA) and Deng’s index are applied to study the performance of input parameters such as insert style, cutting fluid, cutting speed, feed and depth of cut by considering quality characteristics such as surface roughness, material removal rate, interface temperature, specific energy and flank wear. Finally a clear presentation is made for Deng’s method