Browsing by Author "Saha, Sujoy"

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Effect of internal load and temperature on graded spherical shell
(Indian Maritime University, Kolkata Campus, 2023) Balmiki, Sanjay; Saha, Sujoy
In this work, the effect of internal pressure in a functionally graded hollow spherical shell is theoretically studied. The material properties through the graded direction are assumed to be non-linear with power law distribution. In order to obtain the effect of internal pressure and temperature on the design of pressure vessel, Navier and heat conduction equations are solved by direct method. The pressure variation and the mechanical stress distribution such as radial stress distribution and hoop stress distribution along the radial direction are presented in a sequential manner. The radial distribution of temperature has also been depicted in the result and discussion section. As a result of which it may be concluded that the material which has lower power law index is beneficial in terms of generation of lower thermal stress. The study also aims to understand the influence of autofrettage on stress distribution and load bearing capacity in thick spherical shells. Analytical equations, based on the Maximum Shear Stress theory and Distortion Energy theory, are derived to determine the optimum radius of the elastic-plastic juncture, known as 𝐶𝑜𝑝𝑡 in autofrettage technology. The results demonstrate that autofrettage increases the pressure inside the shell, enhancing its ability to withstand higher internal pressures.
Enhancement of heat transfer of laminar flow of viscous oil through a circular tube having integral axial rib roughness and fitted with helical screw-tape inserts
(Begell House Inc., 2012-01-01) Saha, Sujoy
The experimental friction factor and Nusselt number data for laminar flow through a circular duct having integral axial rib roughness and fitted with helical screw-tape inserts have been presented. Predictive friction factor and Nusselt number correlations have also been presented. The thermohydraulic performance has been evaluated. The major findings of this experimental investigation are that the helical screw-tape inserts in combination with integral axial rib roughness perform better than the individual enhancement technique acting alone for laminar flow through a circular duct up to a certain value of the fin parameter.
MHD Laminar Modeling and Numerical Simulation on Ferromagnetic Fluid Flow in a Channel /
(Begell house inc., 2016-01-01) Saha, Sujoy
This study numerically investigated two dimensional, incompressible, Newtonian and electrically conducting laminar fluid flow characteristics under the consideration of MHD phenomenon. In this work the water base magnetic fluid, flowing through a channel under the action of magnetic field, is applied along axial direction, has been considered. The computational investigation has been performed with respect to the formation of stream line contour, vorticity magnitude contour, tangential velocity contour, wall static pressure, and wall shear stresses. The continuity and momentum equations, considering laminar and Magneto hydro dynamics (MHD) are solved for magnetic number arising from MHD of 3.66 and for Reynolds numbers ranging from 80 to 200. The above mentioned flow characteristics have a greater importance in case of various industrial applications such as diffuser, combustor, heat exchanger, mixing chamber, industrial equipment, chemical processing unit etc., which are worth mentioning.
Numerical analysis of flow characteristics of a fluid flowing through an orifice in a marine piping system
(Indian Maritime University, Kolkata Campus, 2024) Maji, Avijit; Saha, Sujoy
Over the last few decades expensive research work has been performed by many researchers on the monitoring of rate of fluid flow through various pipes. Moreover, in the marine industry, it's important to conduct a detailed analysis of the uncertainties associated with flow measurement. It has been also seen that the coefficients, which are used for orifices are based on empirical data. Therefore, accurately predicting the impact of complex geometry and flow separation from the orifice in the flow have become crucial challenges for many researchers. From the review of the literature, it has been noted that a systematic detailed investigation of the flow through the orifice has not been done so far. Thus, in the present study a systematic details numerical investigation has been conducted for incompressible turbulent flow of water through a square edge orifice plate with considering various Reynolds numbers ranging from 153 to 273 and Bita ratios from 0.3432 to 0.6289. The standard design of ISO 5167-2 has been used in the present investigation. In this work, the simulations have been performed by using the ANSYS Fluent. The standard k-ε model has been selected for the turbulence flow analysis. The streamline contour, velocity contour, pressure contour, centreline axial velocity, wall pressure, radial profile of turbulent kinetic energy, and turbulent dissipation rate are presented in the results and discussion section in a systematic manner. From the analysis, it has been noted that the pressure drops from the orifice plate up to the vena contracta increase with increasing the Reynolds numbers and the beta ratio. It has also been observed that the pressure affects the jet-like flow in the core region, the recirculation zone, the reattachment, and the shear regions on the downstream side of the orifice. The location of vena contracta is also be estimated from present CFD simulations. Thus, this analysis improves the accuracy of coefficients. Consequently, error may be minimized in view of monitoring the rate of fluid flow in marine systems.
Numerical design on annular dump combustor of a ship
(Indian Maritime University, Kolkata Campus, 2022-08) Soni, Vaibhav; Saha, Sujoy