EVALUATION OF HEAT TRANSFER RATE AND THEIR EFFECTS IN SPHERICAL PRESSURE VESSELS SUBJECTED TO INTERNAL PRESSURE

This paper investigates the various stresses in a spherical pressure vessel which are subjected to pressure. By determining the strains and stress concentration in a vessel, overall performance of the system can be improved with the selection of suitable material. Thermal analysis is carried out to determine the deformations at various points. An improvement in the performance is achieved by using the computational analysis software ANSYS CFX and the comparative tool DOT NET software. By considering various materials, variation in the dimensions, stresses, strains and heat transfer within the system are discusse

REVIEW OF TOPICAL ENLARGEMENT IN LASER BEAM MACHINING

Laser beam technology is a standout amongst the most generally utilized warm vitality based non-contact sort progress machining process which can be connected for entire scope of materials. The cost of slicing hand-to-machine materials by customary mechanical machining procedures is high because of the low material expulsion rate and short device life, and a few materials are unrealistic to be cut by the traditional machining process. Laser beam/pillar is focused for softening and vaporizing the undesirable material from the parent material. It is reasonable for geometrically complex profile cutting and making smaller than usual openings in sheet metal. It gives portability to natives and cargo, among the locales of Europe and past, while being a motor for monetary development and employments. It is accordingly critical that development is accomplished in a feasible way, thinking about wellbeing and security worries and additionally unfriendly atmosphere pertinent and ecological impacts. Lasers are generally utilized as a part of assembling, correspondence, estimation and restorative. Vitality thickness of the laser beam/pillar can be adjusted by fluctuating the wavelength. This property has made the lasers capable for expelling to a great degree little measure of material and has prompted the utilization of lasers to produce little elements in work section constituents. The basic investigation of different hypothetical and exploratory reviews is utilized to portray the execution of laser pillar miniaturized scale machining on a portion of the propelled manufacturing materials. This paper gives a survey on the different research activities done in laser beam technology. The substance of paper contains a concise presentation of recent development in laser beam and its improvement

DESIGN AND FABRICATION OF LOW COST OPEN CIRCUIT SUBSONIC WIND TUNNEL

A subsonic wind tunnel is a device used to create a fast stream of air through a test area in which an object is kept. This paper will focus primarily on the fabrication process of small scale subsonic wind tunnel, flow visualization analysis on an object and calculation of lift and drag coefficient of an object through experiment. In the present world of obtaining excellence with the most extreme cost sparing and almost all the aircrafts are composed utilizing CAD programming. These plans however should be checked and tried continuously which gives imperatives results in the full scale. The momentum research not just incorporates confirmation of withdrawal cone outline by looking at the speed of air at various segments got amid CFD investigation with the trial values at comparing forces. This design explains the whole method to plan an open circuit subsonic wind tunnel which will be utilized to concentrate on the wind impact on the diverse models of basic components. The plans were made and broke down, bringing about different examinations of various geometries, and giving the required information of course from the outlines. The profile includes a contraction cone area of side 750mm, square test area of side 500 mm, to suit the model and required instrumentation in it, for power and weight estimation. The test section has a dimension of 340mm x 360mm x 500mm which is companionable to the outlet and inlet of the nozzle and diffuser respectively with the mean velocity of 15 m/s. A straight portion before the test chamber is given to allow the yield of withdrawal zone to offset before it accomplishes the test section

Selective Laser Melting Process Parameter Optimization on Density and Corrosion Resistance of 17-4PH Stainless Steel

The 17-4 PH Stainless Steel material is known for its higher strength and, therefore, extensively used to build structures for aerospace, automotive, biomedical, and energy applications. The parts must operate satisfactorily in different environmental conditions to widen the diverse application. The selective laser melting (SLM) technique build parts cost-effectively, ensuring near-net shape manufacturability. Laser power, scan speed, and hatch distance operating at different conditions were used to develop parts and optimize for higher density in printed parts. Laser power, scan speed, and hatch distance resulted in the percent contribution towards density equal to 73.74%, 24.48%, and 1.78%. The optimized conditions resulted in higher density and relative density equal to 7.76 g/cm 3 and 99.48%. Printed parts' corrosion rate and wear loss showed more stability in NaCl corrosive medium even at 75 °C than 1M of HCL corrosive medium. Less pitting corrosion was observed on the samples treated in NaCl solution at 25 °C and 75 °C at 72 Hrs than in HCL solution. Therefore, 17-4 PH SS parts are best suited even in marine applications

Dynamic-mechanical properties as a function of luffa fibre content and adhesion in a polyester composite

In this work, the characteristics of a vegetable fibre (luffa cylindrica) polyester composite are studied as a function of fibre surface treatment (with NaOH, Ca(OH)2 and silane) and fibre content (30%, 40% and 50%). Composites were prepared through compression moulding and characterized with thermogravimetric and dynamic-mechanical analyses. Higher storage modulus was obtained with Ca(OH)2 treated composites, reaching nearly 70% increase. Higher loss modulus (E”) was noted in for silane treated fibre (at 50%) and a high peak in damping factor was noted for Ca(OH)2 treated fibre (at 50%). Cole-cole plot showed highest homogeneity for the Ca(OH)2 treated composites. Electron microscopy revealed the fracture modes in static tested composites. The general properties obtained indicate that the composites can only be used for low loading applications

Numerical investigation of heat transfer enhancement in solar air heaters using polygonal-shaped ribs and grooves

Solar air heating thermal systems have found extensive utilization in a broad array of industrial and residential settings, playing a pivotal role in the conversion and reclamation of solar energy. Implementing repeated artificial roughness in the surfaces has the potential to augment thermal performance in solar air heaters (SAHs). This study presents a numerical investigation of SAHs with artificial rough surfaces, consisting of polygonal-shaped ribs and grooves located at different places inside the rectangular duct, that improve thermal efficiency. ANSYS Fluent software was employed to simulate the SAH with different relative pitch distances of p = 10 mm and 20 mm and relative rib heights e/d = 0.09–0.045. The working fluid air flows at different Reynolds numbers (Re), ranging from 3,800 to 18,000. Nusselt number (Nu), friction factor (f), and Thermal Hydraulic Performance (THP) are parameters to evaluate the performance of the SAH. The renormalized group (RNG) k-ϵ turbulent model was implemented in this simulation. The study outcomes indicate that increasing the rib height improves the heat transfer rate and nonetheless increases pressure drop while increasing the pitch distance. The higher Nusselt number (Nu) is 3.762 attained at p = 10 mm and 3.420 at p = 20 mm in the center-positioned rib at Re 3,800. The lower friction factor (ƒ) obtained in p = 20 mm is 1.681 and 0.785 in p = 10 mm in the staggered positioned rib at higher Re 15,000. The optimal THP was achieved at 2.813 at a staggered rib height at a pitch distance of p = 10 mm at Re 8,000. The study’s findings suggest that the incorporation of artificial rough surfaces has the potential to enhance the THP of an SAH