Latest preprints

This study extensively elaborates the approach towards making ease in 3D milling of Titanium Alloy Grade 5; by adapting the controlled parameters and specific strategies in cutting tool encroachment in milling. Every manufacturer is anxious about the machinability index (20%) of Ti6Al4V, which affects the machining efficiency proportionally. During machining, Phase alteration above the 8820C produces a Beta lamellar equiaxed microstructure, which is hard; also, limited thermal conductivity allows the generated heat towards the cutting tool to lead the Thermo-assisted wear. Higher temperatures also initiated chemically eagerness of Ti6Al4V and reacted with cutting tool edge and escorts towards catastrophic failure. The difficult Machinability demonstrates the detrimental notable effect on the cutting tool's health and follows the Ti6Al4V surface quality. The Cooling methods can flush out chips and frictional heat with ample lubrication, desirably controlling the worse effect of Machinability to some extent blissfully. The cutting tool material and coating, has chemically inert and excellent thermal conductivity with an aggressive rake angle with higher relief angle, improves the shearing tendency of Ti6Al4V by avoiding smearing, ultimately speculated surface quality with desired Tool life through higher Machining efficiency in milling.

A simple and effective multi-attribute decision-making method, named as "Best Holistic Adaptable Ranking of Attributes Technique (BHARAT)-II”, to choose the best refrigerant for air conditioning systems is presented. The thermodynamic properties of the refrigerants, and their environmental, and economic performances are also considered for the selection. Two case studies are provided to demonstrate the proposed multi-attribute decision-making method. The first case study addresses the problem of selecting the best refrigerant for residential split air conditioners out of 15 alternative refrigerants considering 12 selection attributes; the second case study addresses the problem of selecting the best refrigerant for automobile air conditioning systems by considering 14 alternative refrigerants and 13 selection attributes. The results of the proposed decision-making method are compared with those of other well-known multi-attribute decision-making methods such as EDAS, TOPSIS, and MOORA. The proposed method is shown to be simple to implement, providing a logical way for allocating weights to the selection attributes and is useful to solve the best alternative refrigerant selection problems of the residential as well as industrial refrigeration and air conditioning.

Generation of vortices in the fin and tube heat exchanger is one of the common methods to reduce the air-side thermal resistance. This study deals with the enhancement of heat transfer in the air side using conventional rectangular and sinusoidal sine wave vortex generators. The vortex generators are placed in the downstream location of the tube in the common flow-down configurations and the range of Reynolds number is maintained about 400 to 1100. The results of the above vortex generators are compared with baseline configuration based on thermos-hydraulic criterion parameters like variation in the flow structure, variation in the temperature distribution, variation in the pressure distribution, variation in the friction factor, and overall thermal enhancement factor. Based on the comparative numerical analysis, sinusoidal and conventional rectangular winglet shows good heat transfer enhancement in that they have a large pressure loss penalty.

The need for creating realistic body parts and anatomical models using additive printing was long ago recognised. The paper "Rapid prototyping approaches for anatomical modelling in medicine" by M. McGurk et al. in Ann. R. Coll. Surg. Engl. 1997; 79; 169-174, which discussed 3-D printing of models, summarised the state of the art in this subject some years ago. Models were made by sprinkling liquid over a layer of precursor powder using inkjet printer nozzles to form a solid, thin slice. For each additional slice, the printing procedure was repeated until the item was finished as a "green state" component, which was then burned in a furnace to sinter it. The product was then subjected to further processing to create a full density portion. Large item 3D printing has been simpler than in previous years because to the development of software for computer controlled robotic XY motion systems used in the semiconductor and optical sectors. Layered building of 3D things is now a comparatively cheap and quick operation for 3D printing equipment thanks to software applications like SolidWorks, AutoCAD 360, and similar software products. Larger things may be 3D printed by either attaching rails above the print nozzles for X-Y motion directed from above the nozzles, or by positioning the object to be created on an X-Y table with motion supplied below the nozzles. The current work attempts to construct a 3D printing setup that utilises two robotic arms to print a single component. Here, the bed will be swivelled to a specific angle to prevent the robotic arms from becoming entangled, and the robotic arms will also move 180 degrees from their mean positions. Additionally, the related software will be developed locally in our lab, resulting in a shorter printing time and higher level of accuracy.