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Author

Manoj Kumar

Other affiliations: Indian Register of Shipping
Bio: Manoj Kumar is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Computational fluid dynamics & Volume of fluid method. The author has an hindex of 2, co-authored 4 publications receiving 14 citations. Previous affiliations of Manoj Kumar include Indian Register of Shipping.

Papers
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Journal ArticleDOI
TL;DR: In this paper, an unstructured grid consisting of hexahedral cells has been used in the volume of fluid (VOF) model to quantify the tank wall effects on resistance estimation of ship models.

8 citations

Proceedings ArticleDOI
16 Feb 2004
TL;DR: This paper presents a methodology to utilize such unused EMBs as large look-up tables to map multi-output combinational sub-circuits of the application, which, otherwise would be mapped on to a number of small look-ups available on the FPGA.
Abstract: Modern day field programmable gate arrays (FPGA) include in addition to look-up tables, reasonably big configurable embedded memory blocks (EMB) to cater to the on-chip memory requirements of systems/applications mapped on them. While mapping applications on to such FPGAs, some of the EMBs may be left unused. This paper presents a methodology to utilize such unused EMBs as large look-up tables to map multi-output combinational sub-circuits of the application, which, otherwise would be mapped on to a number of small look-up tables (LUT) available on the FPGA. This in turn leads to a huge reduction in the area of the FPGA, utilized for mapping an application. Experimental results show that our proposed methodology, when employed on popular benchmark circuits, can lead to additional 50% reduction in area utilized when compared with other methodologies reported in the literature.

5 citations

Proceedings ArticleDOI
01 Jan 2008
TL;DR: In this paper, the authors used a general Computational Fluid Dynamics code to compute flow induced ship motions in waves using a Wigley hull model and a finite-volume method on a structured grid composed of hexahedral cells.
Abstract: The work aims to validate the usage of a general Computational Fluid Dynamics code to compute flow induced ship motions in waves. The motions of the ship and the wave dynamics have been implemented in the RANSE solver through user codes. Rigid body Motion equations are solved every iteration and the mesh is updated subsequently. The model chosen is a Wigley hull, for which experimental data are available in published literature. The 3D viscous free surface flow has been solved using finite-volume method, on a structured grid composed of hexahedral cells. The waves, which are produced in the numerical tank, are compared with experiments. The motion results, obtained in the current work, have also been compared with the results obtained using potential flow solver, SWAN. The ship motions predicted by the numerical simulation agree well with the experiments and promises to be a robust method for solving more practical and complex problems like prediction of slamming loads and ship behavior in an irregular seaway.Copyright © 2008 by ASME

2 citations

Book ChapterDOI
01 Nov 2019
Abstract: Waste plastic is a conventional source of energy. It can be transformed into oil by thermal degradation method such as pyrolysis. In this work, pyrolysis plastic oil (PPO) was prepared by microwave pyrolysis method using waste plastic. The plastic oil was analysed, tested and used as the properties of it were similar to that of diesel. The single cylinder direct injection diesel engine was fuelled with different blends at different loads from no load to full load condition. The performance, combustion characteristics and emissions were recorded and compared with that of diesel. Based on the results, it is found that the brake thermal efficiency for blends PPO20, PPO40, PPO60, PPO80 and PPO100 at 90% of full load condition were lower by 3.9, 6.8, 8.3, 9 and 9.7%, respectively, with respect to diesel when the engine was operated at a constant speed of 1500 rpm. Specific fuel consumption for blends PPO20, PPO40, PPO60, PPO80 and PPO100 at 90% of full load were higher by 0.4, 1.2, 2, 3.6 and 6%, respectively, as compared to diesel at constant speed (1500 rpm). The NOx emissions for blends PPO20, PPO40, PPO60, PPO80 and PPO100 at 90% of full load were higher by 7.65, 13, 17, 23 and 24.2%, respectively, as compared to diesel while engine was running in constant speed (1500 rpm). The CO emissions for PPO blends PPO20, PPO40, PPO60, PPO80 and PPO100 at 90% of full load were lower by 6.5, 17.4, 26, 30.4 and 7.6%, respectively, as compared to diesel at constant speed (1500 rpm). The UHC emissions for PPO blends PPO20, PPO40, PPO60, PPO80 and PPO100 at 90% of full load were lower by 6.5, 17.4, 26, 30 and 39%, respectively, as compared to diesel at constant speed (1500 rpm). It can be concluded that the plastic oil could be used as a substitute fuel in diesel engine.

Cited by
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Journal ArticleDOI
TL;DR: An optimization design method based on the CFD is proposed, which combines the Rankine source method with the nonlinear programming (NLP) to obtain a hull form with the minimum wave making resistance.
Abstract: The hull form optimization concerns one of the most important applications of wave making resistance theories. In order to obtain a hull form with the minimum wave making resistance, an optimization design method based on the CFD is proposed, which combines the Rankine source method with the nonlinear programming (NLP). The bow-body shape is optimized with the minimum wave making resistance as the objective function. A hull form modification function is introduced to represent an improved hull surface, which can be used to generate a new smooth hull surface by multiplying it by the offset data of the original hull surface. The parameters of the hull form modification function are taken as the design variables. Other constraint conditions can also be considered, for example, in optimizing the lines of the bow, appropriate displacements can be taken as the basic constraints. S60 hull form is selected as the original hull. Three improved hulls are obtained by optimal design. Rankine source method proves to be an effective method in ship form optimization based on analysis of the resistance performance and lines of the improved hull.

62 citations

Journal ArticleDOI
TL;DR: In this article, the authors investigated the hydrodynamics issues associated with AUVs (autonomous underwater vehicles) as they approach a cone-shaped dock, which is proposed by most AUV docking systems for the AUV's protection and simplification.

60 citations

Journal ArticleDOI
TL;DR: In this article, the authors investigated the performance of passive and active anti-roll tank (ART) systems and compared their performance in each of the three sea conditions, and found that active ARTs are more effective in reducing the roll motion.

57 citations

Journal ArticleDOI
Hai Huang1, Zexing Zhou1, Li Hongwei1, Hao Zhou1, Yang Xu1 
TL;DR: In this paper, the authors investigated the influence of the side wall and support struts on the hydrodynamic coefficient prediction for Autonomous Underwater Vehicles (AUVs) experiments and found that the hydrogynamic coefficients tend to be constant with the CWC width parameters increasing.

12 citations

Journal ArticleDOI
TL;DR: In this article, an effective tool to predict a ship's zigzag motion and azimuth propulsion system behavior in calm water and different sea conditions, and the resulting speed loss has been carried out.

10 citations