Research Publications
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Item Numerical study on maneuvering a container ship in shallow water waves /(IJIRSS, 2023-09-15) Mallampalli, Premchand; Janardhanan, Sheeja; Karottu, KesavadevVarikattu; Ommi, GnaneswarNumerous practical and mathematical techniques have been piloted to study ships’ behavior in deep water conditions with and without waves, and shallow water conditions without waves, while only limited investigations have been carried out to assess ships’ behavior in shallow waters with wave conditions as the flow around the stern regionandappendages and the interaction effects are intricate. Therefore, this study attemptsto understand the infrequently explored subset of a vessel’s behavior in regular waves in shallow water conditions(channel depth to ship draft ratio taken as 1.5). A container ship (S175) model scaledat 1:36 was the subject of a numerical study inwhich it was subjected to static and dynamic maneuver simulations in head sea conditions. The waves were induced using the dispersion relationship of waves in a given depth. The trends of forces and moments acting on the hull while undergoing maneuvering motions were obtained using a smooth particle hydrodynamics-based computational fluid dynamics solver. The resulting periodic trends of forces and moments were analyzed using the Fourier series method to extract the Fourier coefficients and,in turn,calculate the hydrodynamic derivatives. The trajectories in turning circle and zigzagmaneuverswere also simulated using a MATLAB code. The results demonstrate an increase in trajectory parameters and improvement in counter maneuverability owing to the complex flow physics around the hull whenencountering regular waves in shallow water conditionscompared to waves in deep watersand a lack of waves in shallow waters.Item Shape improvisation of the solar panels on the roof of an electric vehicle /(Springer Nature, 2021-06-15) Janardhanan, SheejaIt is a well-known fact that bluff body appendages induce augmented drag on a vehicle. Hence, aerodynamic design is inevitable for vehicles for better power and performance. The present work is focused on transforming the present shape of the SCMS School of Engineering and Technology’s solar electric vehicle’s solar roofing from a bluff model to aerodynamic. Computational fluid dynamics studies are carried out on the present shape. The top of the vehicle, housing of the solar panel, is chamfered in steps and a new shape is evolved at ensuring an aerodynamic design. Three different shapes are studied in the present work. The one with minimum drag is suggested for the vehicle. The reduction in the area of the solar panels due to the shape improvisation is compensated for by increasing the surface area to retain the same power input. The proposed new shape is found to reduce the overall drag of the vehicle.Item Comparitive CFD study for a ship hull with sonar dome a different positions(IIT, Kharagpur, 2011-12) Jaya Simha, B. Pradeep; Das, H. N.; Niranjan Kumar, I. N.Sonar Domes are traditionally Hull Mounted and is placed in between bow and the mid ship. Placing the dome in such a way greatly reduces the risk of damage in heavy seas but it requires extreme design consideration. However, bow mounted domes also exhibit hydrodynamic advantages and are becoming more and more popular with time. A bow mounted dome may work like a bulbous bow and helps reducing the drag of the ship. The position of the appended dome greatly influences the flow near the hull and greatly affects the performance of the hull. Since there is a scope to position the dome at various locations along the hull, a CFD analysis is done to determine the performance of hull at three different positions of the ship and the results are compared in this paper. A detailed study of flow including streamlines, drag, wake at different regimes of flow etc., is made for different configurations of the dome. The sonar dome is placed at different locations beginning from the bow end to the mid-shipsection along the center-line of the ship and the performance of the hull is studied. The surface model of the sonar dome with hull is generated using modeling package CATIA. Surface and volume mesh is generated thereafter using ICEM CFD (v 10.0). The mesh is imported for flow analysis into Fluent (v 6.2) software. RANS equation was solved for turbulent, viscous and steady flow. However, the free surface could not be resolved well with Fluent and hence wave-resistance could not be estimated with Fluent. SHIPFLOW software was used to get wave resistance. SHIPFLOW solves potential flow equations for estimating waves and predicts skin friction from boundary layer equations. The CHAPMAN solver of SHIPFLOW was also used to estimate the fully turbulent flow near the stern region. Whereas, the RANS solution of Fluent is expected to predict viscous resistance more accurately the wave resistance may be confidently predicted from potential flow solver of SHIPFLOW. Use of different flow-equations for estimating different components of ship-resistance is an interesting aspect of this paper. Finally the performances of ship hull with sonar dome at different positions are compared to obtain the best location.Item Shape improvisation of the solar panels on the roof of an electric vehicle(Spingerlink, 2021-08) Sekhar, Gautam C.; Krishna, D Gokul; Abhimanue, H.; Meeran, Fadil K; Janardhanan, SheejaIt is a well-known fact that bluff body appendages induce augmented drag on a vehicle. Hence, aerodynamic design is inevitable for vehicles for better power and performance. The present work is focused on transforming the present shape of the SCMS School of Engineering and Technology’s solar electric vehicle’s solar roofing from a bluff model to aerodynamic. Computational fluid dynamics studies are carried out on the present shape. The top of the vehicle, housing of the solar panel, is chamfered in steps and a new shape is evolved at ensuring an aerodynamic design. Three different shapes are studied in the present work. The one with minimum drag is suggested for the vehicle. The reduction in the area of the solar panels due to the shape improvisation is compensated for by increasing the surface area to retain the same power input. The proposed new shape is found to reduce the overall drag of the vehicle.Item Aerodynamic analysis of deployable wing arrangement for space shuttle(Spingerlink, 2022-11-19) Chandran, Vidya; Rajendran, Poornima; Gopakumar, Shabu; Arun Kumar, K. S.; Nikhilraj, C. A.; Janardhanan, SheejaThe study space for morphing wings is astonishingly wide and provides ample scope for enhancements up against fixed wings. Morphing-wing research has accumulated considerable recognition in the aerospace community over the last decade, and a folding wing is a promising approach that can improve aircraft proficiency over multiple varieties of missions which conclusively enhance the capability of the space shuttle. In this paper, the conventional shape of the wings is being refashioned to serve the requirements for maintaining the flight and also for navigation. The idea was sparked by the traditional Japanese fan and has a hinged mechanism similar to that of the fan. This work introduces a novel concept for retractable dynamic wings on a space shuttle. Modeling of the spacecraft with modified wings is done in SOLIDWORKS. The aerodynamic analysis is performed using the computational fluid dynamics (CFD) method with ANSYS FLUENT® (2020 R1) as the solver. The aerodynamic force coefficients are estimated for five different specific deployment phases, viz., zeroth (0°), one quarter (7.5°), half (15°), three-quarter (22.5°), and full (30°) phases. The result reveals that the coefficient of drag drops and the coefficient of lift rises from the primary phase to the final phase providing promising inputs into the idea of retractable wings.