Mechanical Engineering

Refrigeration is the applied science which deals with reducing the temperature of a confined space and its content to a predetermined level that is below the ambient temperature. The design of a cooling table is presented. The cooling table is an innovative application in refrigeration system design. The table is a multipurpose table for maintaining a low product temperature whilst still being able to carry out other activities on the table like a conventional table. The design covers thecompressor, condenser, evaporator, table frame, table top, cabinet volume and the covers. The prototype design requires a 70W compressor for three participants.

Since the inception of industrial revolution, a continuous attempt has been made to recover and minimize the waste heat. In the present research paper review on heat pipe is done. Through heat pipe the hot air is used to pre heat the inlet air of 4 stroke diesel engines. Further, the different performance parameter is calculated for the analyzing the effect of pre heat inlet air in comparison of normal air. Variation of Performance is discussed and salient conclusion is drawn which indicates that, a wide scope is available for further research on heat pipe and especially in the relation of IC engine exhaust heat recovery system to preheat the inlet air.

In this paper experimental investigation has been carried out on kevlar/glass angle ply hybrid composites to characterize interlaminar shear strength. With the aim of determining the influence that the structure, a reinforcement type and a sort of resin exert upon the interlaminar strength. Hybrid composites are considered materials of great potential for engineering applications. One advantage of hybrid composite materials for the designer is that the properties of a composite can be controlled to a considerable extent by the choice of fibers and matrix and by adjusting the orientation of the fiber. The scope for this tailoring of the properties of the material is much greater, however, when different kinds of fiber orientations are incorporated in the same resin matrix. Three orientations viz 0?/90?, ±45?and 60?/30? were considered for studies. Mechanical properties such as interlaminar strength, interlaminar stiffness, & peak load of the hybrid composites were determined as per ASTM standards. Vacuum bagging technique was adopted for the fabrication of hybrid specimens. It was observed that orientation at 0?/90?showed significant increase in ILSS properties as compared to other orientation.

Friction-stir welding has received a huge interest in the last few years. The many advantages of this promising process have led researchers to present different theoretical and experimental explanation of the process. The way to quantitatively and qualitatively control the different parameters of the friction-stir welding process has not been paved. In this study, a refined energy based model that estimates the energy generated due to friction and plastic deformation is presented. The effect of the plastic deformation at low energy levels is significant and hence a scale factor is introduced to control its effect. The predicted heat energy and the obtained maximum temperature using the present model are compared to the theoretical and experimental results available in the literature and a good agreement is obtained. 

This article provides a short introduction to Project based Learning (PjBL) that are significant in the mechanical engineering students project MR02/07 development for agricultural product and typical of socio-constructivist of student approaches. The objectives of using PjBL module is producing innovative product by implementation PjBL concept. These project methods will describe deeply the process of development chopper machine with specified code MR02/07. By using PjBL module the process will drive directly from first to the end. Guided with BIE approach and reference models, PjBL module create new 21 century learning era with guided in project development to meet engineering standard and completed on time. It’s works smoothly with guided forms at PjBL module instrument. Engineering students will fulfill the mastery learning in engineering project development methods when use PjBL module for their product development. Please, see project-based learning (PjBL) module that develop for engineering project development at Mechanical Department, Politeknik Kota Bharu, Malaysia.

Generally medicines must be stored and handled in accordance with the manufacturer’s guidelines in order to maintain the quality of the product. Storage outside the recommended temperature range can result in chemical and physical changes to the product which may lead to a loss of efficacy and may cause harm to the patients. In order to maintain such recommended temperatures we generally use vapour compression refrigeration systems. The main drawback is emission of CFC compounds (refrigerants) like R22 upon leakage which could produce harmful effects on environment like ozone depletion. This work aims at developing alternate system for producing refrigeration effect called Thermo Electric Refrigeration. Thermoelectric cooling devices utilize the Peltier effect, whereby the passage of a direct electric current through the junction of two dissimilar conducting materials causes the junction to either cool down (absorbing heat) or warm up (rejecting heat), depending on the direction of the current. Finally using this thermoelectric principle a cold storage is fabricated for preserving the medicines and tested. The minimum cooling temperatures obtained are 10°C at 36°C ambient temperature in 210 minutes that is 3 hours 30 minutes.

Uncertainty of measurement has attracted more researchers in recent past. In this paper ,an attempt is made to review the status of literature in measurement uncertainty. The uncertainty of measurement is related to measurement and calibration process only. A very few literature are available related to uncertainty of measurement. A literature classification scheme is suggested. A number of articles from referred international journals and international conferences are classified based on various methodology (GUM, analytical approach and Monte-Carlo approach etc). The paper shows the country wise awareness in the field of uncertainty. The gap in the research are identified along with the scope of UOM in various application.

In this study, the experiment was conducted using a diesel engine single cylinder four-stroke direct injection, air-cooled. Used in the experiment are four types of fuel: pure diesel, mixture of methanol and diesel by methanol 8% -16% and 24%, three levels of speeds 1500, 2000 and 2500 rpm .we studied in this research The engine performance parameters which included, thermal efficiency, brake specific fuel consumption, noise level ,friction power.

Clay–Ag composite films were based on polyethylene, 0.75 degree and master batch which were produced under the temperature 195-165 degrees Celsius, at 50rpm speed. The morphology and microstructure of the composite films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and transmission electron microscopy (TEM). The tribological behavior was investigated by using a ball-on-disk tribometer in vacuum and in humid air. The crystalline Ag phase dispersed in amorphous Clay and the size of the crystalline Ag increased with the Ag content in the films. The mechanical and tribological properties of Clay–Ag composite films varied with the Ag content. At the content of 42 at %Ag, the composite film had the highest microhardness and elastic modulus. The amorphous Clay in the Clay–Ag 42% composite film made the main function during wear, so the film showed the lowest friction coefficient. The friction coefficients of the Clay–Ag composite films in vacuum were lower and more stable than those in humid air, but the environmental sensitivity of tribological behavior decreased obviously due to the addition of Ag in the films.

In submerged arc welding (SAW), selecting appropriate values for process variables is essential in order to control heat-affected zone (HAZ) dimensions and get the required bead size and quality. Also, conditions must be selected that will ensure a predictable and reproducible weld bead, which is critical for obtaining high quality. In this investigation, mathematical models were developed to study the effects of process variables and heat input on various metallurgical aspects, namely, the widths of the HAZ, weld interface, and grain growth and grain refinement regions of the HAZ. The color metallography technique and response surface methodology were also used.The thermal effect of Submerged Arc that specially depends on the electrical arc, flux type and temperature field of it in workpiece, is the main key of analysis and optimization of this process, from which the main goal of this paper has been defined. Numerical simulation of welding process in SIMPELC method and by ANSYS software for gaining the temperature field of copper, the effect of parameter variation on temperature field and process optimization for different cases of Submerged Arc are done. The influence of the welding parameter for each mode on the dimensions and shape of the welds and on their ferrite contents is investigated.