Conference Papers
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Item Influence of wave and structure parameters on tranmission characteristics of himmf pipe breakwater with five layers([publishername] World Scientific, 2011) Mane, V.; Rajappa, S.; Rao, S.; Hegde, A.V.The paper presents the part results of a series of physical model scale experiments conducted for the study of variation of transmission coefficient Kt due to the horizontally interlaced multi-layered moored floating pipe (HIMMFP) breakwater. The studies were conducted on physical breakwater models having five layers of PVC (Poly Vinyl Chloride) pipes with wave steepness, Hi/gT2 (Hi=incident wave height, g=acceleration due to gravity and T=wave period) varying from 0.063 to 0.849; relative width, W/L (W=width of breakwater and L=wavelength) varying from 0.400 to 2.650 and relative spacing, S/D=3 (S=horizontal centre to centre spacing of pipes and D=diameter of pipe). The transmitted wave heights were measured, and data gathered was analyzed by plotting non-dimensional graphs depicting the variation of Kt with Hi/gT2 for values of d/W (d=depth of water) varying from 0.082 to 0.276; and also variation of Kt with W/L for values of Hi/d varying from 0.060 to 0.400. © 2019, World Scientific. All rights reserved.Item Wave run-up, run-down studies on berm breakwater with concrete cubes as armour units([publishername] World Scientific, 2011) Rao, S.; Shirlal, K.G.; Balakrishna Rao, K.; Janardhan, P.The basic principle involved in the design of berm breakwater is provision of a wide berm at or around the water level with smaller size stones in the armour, which are allowed to move till an equilibrium slope is achieved. This paper presents the results of experimental studies conducted on the wave run-up, run-down characteristics of berm breakwater using concrete cube as artificial armour unit. The experiments were conducted under following conditions, berm width = 0.45m, water depths 0.37, 0.40 & 0.43m, breakwater slope 1:1.5. The weight of concrete cube is 79.5 gm. The wave heights used in the experiments are 0.10, 0.12, 0.14, and 0.16 m and wave periods are 1.6 and 2.0 sec. From the experimental study it is found that the run-up is more for longer period waves in comparison with the shorter period waves. With the increase in deep water wave steepness the run-up and run-down was found to decrease for all the water depths considered. The run-up values (Ru/Ho) vary from 0.52 to 1.08. The range of run-down values (Rd/Ho) varies from 0.45 to 0.88. In berm breakwater the run-up and run-down values were reduced by 35.91% and 23.81% when compared with conventional rubble mound breakwater. © 2019, World Scientific. All rights reserved.Item Inference of optimal speed for sound centrifugal casting of Al-12Si alloys(2011) Rao, S.; Mukunda, P.G.; Rao, S.S.; Sudhakar, K.G.True centrifugal casting is a standard casting technique for the manufacture of hollow, intricate and sound castings without the use of cores. The molten metal or alloy poured into the rotating mold forms a hollow casting as the centrifugal forces lift the liquid along the mold inner surface. When a mold is rotated at low and very high speeds defects are found in the final castings. Obtaining the critical speed for sound castings should not be a matter of guess or based on experience. The defects in the casting are mainly due to the behavior of the molten metal during the teeming and solidification process. Motion of molten metal at various speeds and its effect during casting are addressed in this paper. Eutectic Al-12Si alloy is taken as an experiment fluid and its performance during various rotational speeds is discussed.Item Application of response surface methodology and enhanced non- Dominated sorting genetic algorithm for optimisation of grinding process(Elsevier Ltd, 2013) Dayananda Pai, D.; Rao, S.; D'Souza, R.Optimisation of grinding process during grinding of A16061-SiC composites is investigated in this study. Stir cast A16061-SiC composites with varying volume percentage of SiC reinforcement were ground on a conventional grinding machine with diamond grit grinding wheel. Three grinding variables were studied for simultaneous optimization of material removal rate and surface roughness. Initially, the response surface models for grinding process parameters were developed using response surface methodology. Further, the developed models were optimized using enhanced elitist non-dominated sorting genetic algorithm (enhanced NSGA-II), a time saving algorithm in comparison to conventional NSGA-II. The suitable grinding conditions for multi-objective optimization of the grinding process were obtained from enhanced NSGA-II. Finally the confirmation tests were performed to validate the results obtained from response surface methodology and enhanced NSGA-II. It is observed that, experimental results and the results obtained from enhanced NSGA-II are in close conformance. Hence it is concluded that the developed algorithm can effectively be used for optimization of grinding process. © 2013 The Authors. Published by Elsevier Ltd.Item Plug-in Hybrid Electric Vehicle energy system using home-to-vehicle and vehicle-to-home: Optimizaton of power converter operation(2013) Rao, S.; Berthold, F.; Vittal, K.P.; Blunier, B.; Bouquain, D.; Williamson, S.; Miraoui, A.Plug-in Hybrid Electric Vehicles (PHEVs) are seen to be a step forward in vehicle electrification, to replace ICE based conventional vehicles. Using a PHEV implies that part of the vehicle energy comes from the grid or other sources, such as renewable energy, to charge the battery. However, renewable energy sources being intermittent sources, these new needs would only shift the problem by increasing the number of nuclear and coal power plants, and will not permit solving the problem of pollution or fossil fuel depletion. There is a need to optimize the way, in which the available resources are utilized, in order to reduce dependency on nuclear and coal power plants. This will achieve the overall goal of minimizing pollution, reducing the depletion rate of fossil fuels, as well as reduce the overall cost. This paper proposes a hybrid power system for house energy needs by utilization of renewable energy sources, grid, as well as the PHEV battery source. Emphasis of paper is on optimization of the overall cost of the system, by selecting the most cost effective and feasible option among the available options; namely, renewable energy sources, the grid and the battery of the PHEV. As a prerequisite to the implementation of this scheme, it is desirable to work out an approximate amount of available energy. For this, the efficiencies of the various power converters involved must be determined and taken into account to reduce the energy losses. © 2013 IEEE.Item A survey and comparison of GTS allocation and scheduling algorithms in IEEE 802.15.4 wireless sensor networks(2013) Rao, S.; Keshri, S.; Gangwar, D.; Sundar, P.; Geetha, V.Multimedia applications in the wireless domain require not only contention-based communication, but also reservation based one. The IEEE 802.15.4 standard is widely used for Wireless Sensor Networks (WSNs), and is a standard for low rate, low power and low cost WPANs (Wireless Personal Area Networks). Moreover, it supports the allocation of Guaranteed Time Slot (GTS) to the devices in Contention free period (CFP). With time, many GTS scheduling and allocation algorithms have been proposed with the aim to make maximum the use of GTS. This paper provides a survey and comparison on the current state-of-the-art researches in this important area. We have firstly summarized all the important algorithms proposed till now and then classified and compared them based on various parameters including type, delay, bandwidth, cost, topology, traffic and energy efficiency. © 2013 IEEE.Item Load balancing in cloud based on live migration of virtual machines(2013) Achar, R.; Santhi Thilagam, P.S.; Soans, N.; Vikyath, P.V.; Rao, S.; Vijeth, A.M.Cloud computing is an upcoming trend in the field of computer science in recent years. In cloud, computing resources are provided as service in the form of virtual machine to its clients across the globe based on demand. Huge demand for cloud resources results in overutilization of servers whenever there is a heavy load. It is necessary to distribute the load across the servers in cloud by taking into consideration of allocating the right amount of resources dynamically based on the load to improve the performance of applications running in virtual machines. In this paper we present an algorithm which dynamically allocate resources based on the need and distribute the load across the servers. We conducted the experiment on Xen Cloud Platform. We use response time as a metric. The experiments conducted shows that the proposed algorithm improves the performance of applications running in virtual machines by using the feature scaling and migration. © 2013 IEEE.Item Effect of stiffness on performance of diaphragm wall(Elsevier Ltd, 2015) Yajnheswaran, B.; R, A.P.; C, C.; Rao, S.Diaphragm walls are generally constructed using stiff concrete of same stiffness throughout. Research has shown that as wall flexibility increases, the stress imposed by the soil redistribute and reduces structural forces on wall. Approximately five fold reduction in maximum bending moment occurred when wall stiffness was reduced from that of a 1m concrete section to that of a Frodinghamn1N sheet pile. Unfortunately this beneficial effect is accompanied by greater wall and soil movements (Potts & Day, 1991). So the diaphragm wall cannot be too flexible also. In this paper static analysis of two different diaphragm wall sections of varying stiffness is carried out using PLAXIS software for the load condition existing at deep draft berth of New Mangalore Port, and the performances of these sections are compared with previous study performed by Yajnheswaran et al. (2015). The diaphragm wall sections used in analysis are modeled as single panel. The length of the panel is taken as 5m. Anchors are provided at +2.5m. Soil layer details are obtained from boreholes at NMPT. © 2015 The Authors. Published by Elsevier Ltd.Item Directional asymmetry in random waves near shallow water regions - Its application in physical modelling(Elsevier Ltd, 2015) Jagadeesh, H.B.; Rao, S.; Nagendra, T.; Chalawadi, A.S.In coastal engineering, short wave basin physical model studies have played a very vital role to support the optimization of harbour layout planning. Basically, these models are economical tools for simulation of complex 3-D wave process as in nature with 2-D approximation near wave generation boundary in model. The 2-D state of short period waves generated in model will transform to attain 3-D state due to directional spreading while travelling from the point of generation to the various locations of observations in the model. This transformation process in model depends on various factors like wave approach, bathymetric conditions, interaction with port structures etc. The wave refraction due to oblicity of the wave crest with the sea bed contour in the model is a dominating phenomenon which causes the directional spreading in the model. A shallow basin rigid bed physical model, equipped with random sea wave generating facilities from three directions, has been used to study the directional spreading of waves in the model from the wave generating point to different points of interest within the model. Based on these studies the directional changes for different oblicity of wave approach with respect to sea bed bathymetry in the model was identified. This serves as a good guideline for the location of wave generation boundary in the shallow basin physical model. This is useful in initial planning of the physical model like in identifying the size of the model try and model scale selection. © 2015 Published by Elsevier Ltd.Item Effect of artificial vegetation on wave attenuation - An experimental investigation(Elsevier Ltd, 2015) John, B.M.; Shirlal, K.G.; Rao, S.In the wake of threats posed by rising sea levels and increasing severity of storms, the use of soft measures in coastal protection is acquiring an ever increasing importance. Coastal vegetation acts as a complex interface ecosystem between human communities and the sea and provides important ecosystem services by protecting these communities from coastal hazards, providing critical habitat for fishes and marine invertebrates and primary food source for animals like sea turtles. This paper tries to bring out the effect of simulated vegetation on wave attenuation through an experimental study. The tests were carried out with submerged artificial seagrass and artificial rigid vegetation in a 50 m long wave flume. For wave heights ranging from 0.08 m to 0.16 m at an interval of 0.02 m and wave periods 1.8 s and 2 s in water depths of 0.40 m and 0.45 m, measurements of wave heights at locations along the vegetation were observed. © 2015 The Authors. Published by Elsevier Ltd.
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