Mechanical Engineering

In this study, the deformation behavior of 93Tungsten alloy under the hydrostatic extrusion has been investigated. The hydrostatic extrusion process of 93 Tungsten alloy has been analyzed by means of finite element method (FEM). The numerical results were highly corresponded to the experimental ones. Also the effect of die angle on the extrusion pressure and applied damages to the 93 Tungsten alloy during the process of hydrostatic extrusion has been investigated according to the Cockcroft & Latham damage criterion. As was deduced from results, when the die angle has been considered as 30°, the applied damages to the material during the process were negligible in comparison with higher values of die angle.

This paper deals with demand prediction by combining basic exponential smoothening with Markov based algorithm. This demand prediction is suitable for novel and minimum shelf life products and is suited for small scale retailers and manufacturers, since for them acquisition of costly software tools is out of their financial reach. This paper attempts to arrive at predicting a fixed value of demand which will enhance the profit. The Exponential smoothing process involves comparing the latest observation with the previous weighted average and making a proportional adjustment, governed by the coefficient ?, known as the smoothing constant. By convention we constrain the coefficient to the range, so that only a part of the difference between the old mean and the new observation is used in the updating, 0<?<1.Initially demand is predicted by using basic exponential smoothing for two successive months and error of demand for each day is estimated. Markov based algorithm is then applied for these errors and the steady state probability is then determined for each state. The demand corresponding to the state with maximum probability is taken as the optimum one and the corresponding profit is estimated. This concept is then implemented for a baked product and the annual savings for a particular product is then established.

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.

The human energized flywheel motor has been adopted for many designs of rural applications in the last two decades. In the recent past a human powered process machine has been developed for brick making, chaff cutter, water pump, blender, wood turning, clothes washing and drying and earthen pot making etc [1]. The machine consist of human powered flywheel motor using a bicycle drive mechanism with speed increasing gearing and a flywheel, which drive the process unit through a spiral jaw clutch and torque increasing gearing [2]. The operator puts energy is stored, pedaling is stopped and the energy in the flywheel is made available to the process unit. Pedal power is the transfer of energy from a human source through the use of a foot pedal and crank system. This technology is most commonly used for transportation and has been used to propel bicycles. Less commonly pedal power is used to power agricultural and hand tools and even to generate electricity. The paper discuss about the application for pedal power technology. The machine is economically viable, can be used by unskilled workers, save time otherwise spent in traditional mixing and can be adopted for human powered process units which could have intermittent operation without affecting the end product.

In an automobile, the wheel plays important role. Through reverse engineering process, better alloy wheel disc designs are possible by capturing the physical dimensions of the existing wheel. The objective of the present work is to recommend better material and optimal geometric shape for the wheel disc. The wheel disc is modeled in CATIA and imported to ANSYS. Analysis is done for different models. Analysis results suggest that modified model with smaller radial slots with magnesium zk60 material gives better life. The wheel disc 1.153kg lighter than that in the original design. This design is still in safe condition.

Solid rocket motors are produced in the form of segments which are used as boosters in the launch vehicles. To produce any rocket segment, hardwares are subjected to a series of operations. The rocket hardwares are thin cylindrical shells which are very sensitive to the externally applied loads. During production, a number of handling operations are essential. A suitable interface is to be generated to cater to the production operations. These requirements are met by connecting a circular ring called End Ring to the hardware using the available hardware interfaces. This paper deals with Design and Analysis of HES Dome Side End Ring for Head End Segment.

Methods of design and built become new invention of Outcome Based Education (OBE) at Politeknik Kota Bharu (PKB). This paper prefer to the process of development Bicycle Chopper Hybrid (BCH) with Project Based Online Learning (PBOL) match with OBE that implemented at PKB. The Project Based Online Learning (PBOL) was implemented based on online learning management system call eSOLMS for this project development. This process related with engineering survey, planning, design and development of BCH by using sophisticated technology combination with mechanical machines at inside/outside of workshops at Politeknik Kota Bharu (PKB). The concept of Hybrid vehicle become the new innovation ideas for outcome based project 2012. The product of BCH generate with the power of 1400 rpm motor's to mobilize this vehicle machine. The use of coupling and chain extension as its power mechanism make this project function properly. The testing data’s of product BCH was carry out on Mac 2012 shows that the movement of Bicycle Hybrid Chopper is between 30 till 50 km/h. This speed is safe to ride for a people. In addition, the battery using can function for 3 hours journey. Distance can be traveled is between 10 km depending on battery power. Power Inverter playing role to convert DC current from the battery to AC current turn on. The cost of RM1000.00 for BCH product manufacture is a significant low cost factor of its new creation. This invention shows the effective of Project Based Online Learning (PBOL) implementation match with OBE needs. Hopefully this concept of Project Based online learning become next invention of Project Based Mobile Learning (PBML) of engineering student project development at Polytechnics & Community College, Malaysia.

Heat exchanger is a necessary laboratory equipment in a thermo-fluid laboratory, and lack of this equipment makes learning ineffective. Hence, this study aims to design and construct a shell and tube heat exchanger for laboratory use. To achieve this aim, mechanical and thermal factors were considered. The thermal design was done using the Bell Delaware method. The heat exchanger was designed based on the assumption that there is no phase change, while water at a cold inlet temperature of 15 °C enters the heat exchanger through the tube and hot water at 100 °C enters the heat exchanger through the shell. Results show that the geometry of the heat exchanger favours turbulent flow which enhances heat transfer. This causes a heat load of 107.973 kW to be transferred from the hot fluid to the cold fluid through the tube wall when hot fluid of 0.5 kg/sec flows at a velocity of 0.3 m/s and cold fluid of 2.58 kg/sec flows with a velocity of 1 m/sec. This heat transfer caused the cold fluid temperature to increase by 10 °C as it exits the tube, while the temperature of the hot fluid fell to 45 °C as it exits the shell. The pressure drops in both the shell and tubes were within the allowable range, and hence, accepted. With the overall heat coefficient at 134.23 W/m2K and the efficiency of the system at 73.3%, the study is said to have achieved its objective.

This work focused at designing and fabricating of an aluminium mould for the production of motorcycle brake lever. The pattern making, sand mould and the casting are the major step used to achieve the work. The thermal stress exerted on the mould stood at 0.67GPa which did not exceed the permissible thermal stress for aluminium. In the design of the motorcycle brake lever, it was discovered that a force of 0.58N is required to operate the lever at an effective length of 9cm from the motorcycle head. It shows that the production of motorcycle brake lever can be done locally since aluminium is largely available in the country and hence recommends that more effort should be put in by the Nigerian government for sustainability and development in this area.

Environmenatal factors such as climate change, gradual decrease in water resources and threatened habitants prompted the need to monitor our environment and implement better policies to protect it, thus monitoring soil pF (potential factor) values become increasingly important for environmental monitoring. The commonly available instrument(tensiometer) do not measure the range of available moisture in all soil types rather measures soil water suction. The need to measure the range of available moisture in all soil types with accuracy led to the modification of tensiometer for satisfactory laboratory results. Due to the shortcomings associated with tensiometer readings, the pressure membrane apparatus is an important instrument for optimizing irrigation and erosion prediction models.This pressure membrane with extractor has two main components:a porous plate with air entry pressure and a sealed pressure cell. The soil from which pF value was to be determined was placed in a chamber in which the pressure increased above atmospheric pressure. The side of the chamber which supports the soil consists of a pressure relief valve supported on a pressure hose. This is to ensure that the extractor chamber was not over-pressurized. The soil water potential with the corresponding mositure contents of four soil samples: A (clay soil), B(loamy soil), C (sandy soil) and D (silt) obtained from different locations were determined using pressure membrane apparatus. At a potential of 104hPa, samples A,B,C,D showed moisture content of 0.05,0.25,0.30, and 0.45cm3/cm3respectively. From the obtained results, at potentail close to zero, sandy soil is close to saturation and moisture held in the soil, primarily by capillary forces. From the laboratory analysis, moisture content decreases with high moisture cohesion.