Rajendran, C; Dr.Madhu, G(Cochin University of Science & Technology, September , 2011)
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Abstract:
Wind energy has emerged as a major sustainable source of energy.The efficiency of wind power generation by wind mills has improved a lot during the last three decades.There is still further scope for maximising the conversion of wind energy into mechanical energy.In this context,the wind turbine rotor dynamics has great significance.The present work aims at a comprehensive study of the Horizontal Axis Wind Turbine (HAWT) aerodynamics by numerically solving the fluid dynamic equations with the help of a finite-volume Navier-Stokes CFD solver.As a more general goal,the study aims at providing the capabilities of modern numerical techniques for the complex fluid dynamic problems of HAWT.The main purpose is hence to maximize the physics of power extraction by wind turbines.This research demonstrates the potential of an incompressible Navier-Stokes CFD method for the aerodynamic power performance analysis of horizontal axis wind turbine.The National Renewable Energy Laboratory USA-NREL (Technical Report NREL/Cp-500-28589) had carried out an experimental work aimed at the real time performance prediction of horizontal axis wind turbine.In addition to a comparison between the results reported by NREL made and CFD simulations,comparisons are made for the local flow angle at several stations ahead of the wind turbine blades.The comparison has shown that fairly good predictions can be made for pressure distribution and torque.Subsequently, the wind-field effects on the blade aerodynamics,as well as the blade/tower interaction,were investigated.The selected case corresponded to a 12.5 m/s up-wind HAWT at zero degree of yaw angle and a rotational speed of 25 rpm.The results obtained suggest that the present can cope well with the flows encountered around wind turbines.The areodynamic performance of the turbine and the flow details near and off the turbine blades and tower can be analysed using theses results.The aerodynamic performance of airfoils differs from one another.The performance mainly depends on co-efficient of performnace,co-efficient of lift,co-efficient of drag, velocity of fluid and angle of attack.This study shows that the velocity is not constant for all angles of attack of different airfoils.The performance parameters are calculated analytically and are compared with the standardized performance tests.For different angles of ,the velocity stall is determined for the better performance of a system with respect to velocity.The research addresses the effect of surface roughness factor on the blade surface at various sections.The numerical results were found to be in agreement with the experimental data.A relative advantage of the theoretical aerofoil design method is that it allows many different concepts to be explored economically.Such efforts are generally impractical in wind tunnels because of time and money constraints.Thus, the need for a theoretical aerofoil design method is threefold:first for the design of aerofoil that fall outside the range of applicability of existing calalogs:second,for the design of aerofoil that more exactly match the requirements of the intended application:and third,for the economic exploration of many aerofoil concepts.From the results obtained for the different aerofoils,the velocity is not constant for all angles of attack.The results obtained for the aerofoil mainly depend on angle of attack and velocity.The vortex generator technique was meticulously studies with the formulation of the specification for the right angle shaped vortex generators-VG.The results were validated in accordance with the primary analysis phase.The results were found to be in good agreement with the power curve.The introduction of correct size VGs at appropriate locations over the blades of the selected HAWT was found to increase the power generation by about 4%
Description:
Division of Safety and Fire Engineering,School of Engineering,Cochin University of Science and Technology
Ramakrishnan,Korakandy; Dr.Sankaranarayanan, K C(Cochin University Of Science And Technology, October 28, 1987)
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Abstract:
Induction of growth in the primary marine
fishing industry of Kerala is a sine gua Qgn for improving
the economy of the fishermen, the state's domestic
product as well as earning more foreign exchange for the
country. The State Administration has been trying to
instil growth into the industry eversince the output
of the industry showed marked sign of decline (particularly
after 1975). Significantly, it has attempted to strengthen
the traditional sector, (which is considered to be the
crucial sector of the primary marine fishing industry of
the state) by introducing intermediate technology and by
revamping the organisational structure of the industry.
But it appears that the production system in the primary
marine fishing industry of Kerala has been severely
constrained by the existing technology, organisation of
production and marketing institutions. Regeneration of growth in the industry calls forth an understanding
of the 'process' of growth in the industry and the
need to réorganise it with new technology, and new
organisations. The present study is an attempt to
unraval the process of growth in the primary marine
fishing industry of Kerala since 1951
Description:
Department of Applied Economics
Cochin University of Science and Technology
Ajith Kumar,N; Dr.Sudarsanan, Pillai P(Cochin University of Science and Technology, October 26, 1994)
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Abstract:
The present study describes in detail the major
technological advances in the rubber-growing industry in the lastfour decades. The major technological changes experienced in the rubber plantation industry during the period are the introduction of 'high yielding-planting materials, scientific application of fertilisers, use of pesticides, tapping during rainy season using‘rain guards, use of. yield stimulants and improved tapping methods
School of Management
Studies, Cochin University of Science and Technology
Description:
School of Management
Studies, Cochin University of Science and Technology
Kandoran,M K; Dr.Samuel, C T(Cochin University of Science And Technology, March , 1986)
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Abstract:
Curing is the oldest and cheapest method of preservation of fish allover the world. Fish curing
industry has not shown much improverrent from its primitive nature because this industry is mainly handled by illiterate and less educated fishermen/fisherwomen. They
do not know much about,the importance of scientific methods of fish curing. The cured fish produced by them is unhygienic and poor in quality. Because of the
negligenence and ignorance of the fish curers, a considerable quanti ty of this protein rich food is spoiled and lost every year. Research has been conducted extensively in the Cen tral and State sectors and various remedial measures have been suggested :to improve the fish curing industry in India. Inspi te of the preJudioa against cured fish because of their existing low quality,
research work in recent years have indicated that their quality can be greaUy improved and shelf-life prolonged if the me thods are standardised. To achieve this aim, Cen tral and s tate Departments have already made considerable efforts to transfer the improved methods ~ the fish curing industry by way of traininq courses, demonstrations, Lab, to Land Prograrrmesi film shows, exhibitions, personal discussion etc. As the result of this, fish curers have started adopting the improved practices in fish curing. Still there seems to be a considerable qap between the techmology available and the technology adopted in this field. A comprehensive study on the extent of adoption of improved practices in fish curing and the factors involved in low or non-adoption of certain aspects is lackin~ at present. This gap has to be filled up. The possihle methods for the effective transfer of technology for the production and distribution of high quali ty cured fish products and improvement of soclo-economic condition of fishermen engaqed in fish curing have to be identified.
Description:
School of marine sciences, Central institute of fisheries technology, Cochin University of Science And Technology
Ramachandran,K K; Dr.Seralathan, P(cusat, April 10, 1992)
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Abstract:
The continental shelf of southwest coast of India (Kerala) is broader and . flatter compared to that of the east coast. The unique characteristic feature of the study area (innershelf between Narakkal and Purakkad) is the intermittent appearance of 'mud banks' at certain locations during southwest monsoon. The strong seasonality manifests significant changes in the wind, waves, currents, rainfall, drainage etc., along this area. Peculiar geomorphological variation with high, mid and lowlands in the narrow strip of the hinterland, the geological formations mainly consisting of rocks of metamorphic origin and the humid tropical weathering conditions play significant role in regulating the shelf sedimentation.
A complementary pattern of distri bution is observed for clay that shows an abundance in the nearshore. Silt, to a major extent, depicts semblance with clay distribution . Summation of the total asymmetry of grain size distribution are inferred from the variation of skewness and kurtosis.Factor I implies a low energy regime where the transportation and deposition phases are controlled mostly by pelagic suspension process as the factor loadings are dominant on finer phi sizes. The second Factor is inferred to be the result of a high energy regime which gives higher loadings on coarser size fractions. The third Factor which might be a transition phase (medium energy regime) representing the resultant flux of coastal circulation of the re-suspension/deposition and an onshoreoffshore advection by reworking and co-deposition of relict and modern sediments. The spatial variations of the energy regime based on the three end-member factor model exhibits high energy zone in the seaward portion transcending to a low energy one towards the coast.From the combined analysis of granulometry and SEM studies, it is concluded that the sandy patches beyond 20 m depth are of relict nature. They are the resultant responses of beach activity during the lower stand of sea level in the Holocene. Re-crystallisation features on the quartz grains indicate that they were exposed to subaerial weathering process subsequent to thei r deposition
Description:
Marine Science Division, Centre for Earth Science Studies,
Thiruvananthapuram
Rajan,R V; Seralathan,P(COCHIN UNIVERSITY OF SCIENCE AND TECHNOLOGY, November , 2006)
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Abstract:
The present study addresses to understand the sedimentological properties of the coasts of kodungallur and chellanam, central Kerala to bring out the relationship between the textural, mineralogical and geochemical characters with that of the respective environment. The grain size study of the beach ridge sediments from different pits has been investigated at close intervals, which enables to understand the grain size variations with depth. The sediment samples from various pits of the beach ridges indicate that the sediments range primarily from medium to very fine sand, well to moderately sorted, fine to coarse skewed and leptokurtic to platykurtic. The study area is considered as a prograding coast. Variations in grain size down the pit give three phases of beach building activities i.e.; a coarsening upward sequence in the bottom layers, a fining upward in the middle and coarsening upward in the top. Beach ridges are formed by swash built sediments with cross bedding and setting lag type sediments with seaward dipping/horizontal units.
Geochemical signatures in the study area have been brought out through the analysis of major and trace elements. Iron is significantly enriched and its control over many trace elements is evident. Copper, chromium, cobalt, lithium, lead and zinc show decreasing trend with depth, while sodium, potassium,strontium,nickel and organic carbon increases. The association of many trace elements with organic carbon has also been established. Dissolution of trace elements in anoxic environment, at depth and reprecipitation in the oxic layers, at near or subsurface, are the major mechanism that brought out the variation of certain environmentally sensitive elements
Jiby, K. Gopinath; Dr. K. Sreekumar(Cochin University of Science & Technology, July 30, 2015)
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Abstract:
Polymers with conjugated π-electron backbone display unusual
electronic properties such as low energy optical transition, low ionization
potentials, and high electron affinities. The properties that make these
materials attractive include a wide range of electrical conductivity,
mechanical flexibility and thermal stability. Some of the potential
applications of these conjugated polymers are in sensors, solar cells, field
effect transistors, field emission and electrochromic displays, supercapacitors
and energy storage. With recent advances in the stability of
conjugated polymer materials, and improved control of properties, a
growing number of applications are currently being explored. Some of the
important applications of conducting polymers include: they are used in
electrostatic materials, conducting adhesives, shielding against
electromagnetic interference (EMI), artificial nerves, aircraft structures,
diodes, and transistors.
Bejoy, Varghese; Dr. Nandakumar, V.M(Cochin University of Science and Technology, December 13, 2015)
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Abstract:
Semiconductor lasers with different types of feedback schemes have been an active research
area for many years. Feedback can induce complex phenomena in semiconductor
lasers and their investigations often helped to understand the inner mechanisms of the
laser. The possibility of using high dimensional chaos induced in semiconductor lasers
by delayed feedback, for secure communication systems was a major motivation for intense
research in the subject. Recently these systems also served as a testbed for general
investigations on delay dynamical systems. The present study focuses on the aspects of the
dynamical behavior of semiconductor lasers which are induced by delay feedback.
Santhosh,K R; Dr.Viswanadham,D V(Cochin University of Science and Technology, March , 1987)
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Abstract:
Man's inadvertent interference with the
environment by way of indiscreL¢ industrflflization
has led to the deteriorating air quality in the recent
times. The search is on to find the remedies to
confine the air pollution levels with in their thershold
limits. Theoretical studies play A crucial role in the
control and for abatment of air pollution. Improper
siting of industry is one of the most common reasons
for the increased levels of air pollution in urban
environments. A proper and effective ecological planning
is an essential first step for any region in order to
reduce the effects of air pollution. By means of
theoretical models one can obtain the pollutant distribution
in any urban area, provided the necessary data
are available with the help of which the sites for new
industries could be suggested, given the emission
inventory. Studies on air pollution meteorology serve
and aid the planners to initate remedial actions to
bring down the levels of pollution and also to out—line
the control strategy. In the present thesis some
theoretical studies on air pollution meteorology over
South India are made. The thesis is divided into
six chapters
Description:
Physical Oceanography and Meteorology Division
School of Marine Sciences, Cochin University of Science And Technology