Hydro Science & Marine Engineering
EISSN : 2661-331X
Published by: Bilingual Publishing Co. (10.30564)
Total articles ≅ 34
Latest articles in this journal
Published: 22 September 2022
Hydro Science & Marine Engineering, Volume 4; https://doi.org/10.30564/hsme.v4i2.4677
Change silt charge of water in the rivers can negatively be reflected inthroughput the rivers beds, stability of coast, change of river structures, disappearance of boggy places, etc. In work questions of variability silt chargewaters in the river Sluch in time and on length of the river are considered.It is revealed that in time average and maximal silt charge waters decrease.While on length of the river change silt charge waters is shown not precisely, similar on some increase silt charge waters to a mouth of the river. Theresearches led by the factorial analysis and graphic-analytical method onthe basis of long-term materials of measurement of charges of water haveshown that, on a part of posts average depth of water in the river grows, andon others - cyclically changes with the general tendency to reduction. Average speed in them, accordingly, falls and grows. Stratification of interrelations of a silt charge with other factors on years is observed. The reasons ofreduction of a silt charge are: 1) agrarian and forest meliorative actions ona catchments of the river, hydraulic engineering construction; 2) grassy bedof the river; 3) change of a climate that promotes growth of temperature ofa surface of soils and grassy bed of the river. In developed natural-climaticconditions expediently application on reservoirs of the antierosion organization of territory of the land tenure including agrarian- forests- meliorativeactions that will allow to adjust outflow of a moisture from reservoirs tolower warming up of a surface of the soils, to provide against a high waterprotection and it will favorably be reflected in manufacture of agriculturalproduction.
Hydro Science & Marine Engineering, Volume 4; https://doi.org/10.30564/hsme.v4i2.4692
Local scour is the reduction of original bed level around any hydraulicstructure. Bridge failure due to scouring has made researchers study thecause of scouring and predict the scour depth and pattern around bridgepiers and foundations. Several investigators have extensively studiedlocal scour around isolated bridge pier, but modern designs of the bridgescomprise of wide span and thus group of piers rather than a single pier. Theflow and scour pattern around group of piers are different from the case of asingle pier due to the interaction effect. The objective of present study is toinvestigate the effect of mutual interference of bridge piers on local scourexperimentally around two piers in non-cohesive bed. Experiments werecarried out on model bridge piers of circular cross section in a meanderingchannel. It was observed that when front and rear piers were placed at anangular displacement of θ = 40° and 80° respectively, maximum depth ofscour is maximum. Here θ is the angle the line drawn at the inlet of bend tothe line joining the centre of curvature and any point on the outer portion ofthe bend.
Hydro Science & Marine Engineering, Volume 4, pp 8-15; https://doi.org/10.30564/hsme.v4i1.4489
Offshore Horizontal Axis Wind Turbines (HAWT) are used globally as a source of clean and renewable energy. Turbine efficiency can be improved by optimizing the geometry of the turbine blades. Turbines are generally designed in a way that its orientation is adjustable to ensure the wind direction is aligned with the axis of the turbine shaft. The deflection angle from this position is defined as yaw angle of the turbine. Understanding the effects of the yaw angle on the wind turbine performance is important for the turbine safety and performance analysis. In this study, performance of a yawed HAWT is studied by computational fluid dynamics. The wind flow around the turbine is simulated by solving the Reynolds-Averaged Navier-Stokes equations using software ANSYS Fluent. The principal aim of this study is to quantify the yaw angle on the efficiency of the turbine and to check the accuracy of existing empirical formula. A three-bladed 100-m diameter prototype HAWT was analysed through comprehensive Computational Fluid Dynamics (CFD) simulations. The turbine efficiency reaches its maximum value of 33.9% at 0° yaw angle and decreases with the increase of yaw angle. It was proved that the cosine law can estimate the turbine efficiency with a yaw angle with an error less 10% when the yaw angle is between –30° and 30°. The relative error of the cosine law increase at larger yaw angles because of the power is reduced significantly.
Hydro Science & Marine Engineering, Volume 4, pp 36-38; https://doi.org/10.30564/hsme.v4i1.4673
Hydro Science & Marine Engineering, Volume 4, pp 16-26; https://doi.org/10.30564/hsme.v4i1.4568
Offshore engineering projects require the management of a huge amount of heterogeneous georeferenced data - among others metocean, geophysical, geotechnical, and environmental, which need a Data Model, data visualization and data analytics features on a common geographic basis. A Digital Data Platform (DDP) has been developed on a GIS ambient with the aim to speed up the engineering design process (i.e. minimization of routine operations), and also prevent misalignment of the data originating from different sources from Owner to Suppliers and any potential loss of information. The proposed GIS architecture is composed by two main components: i) the Data Model geodatabase, and ii) the GIS-Model Toolbar add-in. The proposed development represents a step forward on the definition of a common specification and dictionary for offshore project execution overcoming the current bottlenecking and inefficiency on the design phases between the project owner and the engineering contractor. The paper illustrates “what” and “how”, and in particular: i) the geodatabase and Data Model framework, ii) the required parameters to be organized and stored for offshore engineering design, and iii) the widgets implementation (i.e. GIS-based tools). Its application on a case study project with practical examples is presented.
Hydro Science & Marine Engineering, Volume 4, pp 27-35; https://doi.org/10.30564/hsme.v4i1.4553
Present study is aimed at assessment of Bholari river sand for its geotechnical characterization and suitability as fine aggregate which is being quarried in Jamshoro district, Sindh, Pakistan. For this purpose, sand samples (n=11) were collected from quarry sites and main river channel. Physical properties reveal that Bholari sand is mainly coarse to fine in size (0.2 mm-5 mm). Average values of fineness modulus, specific gravity, bulk density and void content of collected samples are 2.58, 2.56, 1659.90 kg/m3 and 35.12% respectively which varied within the corresponding permissible ranges of ACI (American Concrete Institute). Carbonate content of about 57.59% is also in agreement with corresponding range for fine aggregate. Petrographic examination revealed that Bholari River sand mainly comprises of quartz and rock fragments with subordinate limestone fragments. As per classification of Dott (1964), Bholari sand is lithic arenite where quartz (50%) occurs as main mineral followed by rock fragments (30%), feldspars (15%) and other opaque minerals (5%). Texturally, the sediments are angular (77%) to sub-round (33%). All these physical properties lie within the range set by National Highway Authority (NHA) and American Standard of Testing Material (ASTM). It is concluded that Bholari River sand is suitable for use in concrete mixed with cement and asphalt.
Hydro Science & Marine Engineering, Volume 4, pp 1-7; https://doi.org/10.30564/hsme.v4i1.4462
Spur dykes are the structures which are used to protect the eroding bank of rivers. They are sometimes also used to safeguard the life of many structures such as bridge piers, abutments etc. The efficiency of spur dykes has been checked in straight channels by conducting model tests in laboratories by many investigators. Very few studies were done in curved channels. In present work an attempt has been made to study the effect of location of spur dyke on bed and scour around bridge pier in curved open channel (bend angle = 80o ) with time. Experiment has been carried out in 80o channel bend at constant discharge (3.5×10–3 m3 /s) and bridge pier is located at angular displacement ϴ = 60o . Here ϴ is the angle the line drawn at the inlet of any bend to the line joining the centre of curvature and any point on the outer portion of the bend. It is found that maximum scouring occurs at ϴ = 0o and 20o along inner wall and at ϴ = 60o and 80o along outer wall. It is also found that scouring around bridge pier is more in the vicinity of pier and decreases with increase in distance from pier. The most suitable location for spur dyke to protect bridge pier is at angular displacement ϴ = 20o . Scour developed rapidly during initial time and then rate of scouring decreases with elapse of time.
Hydro Science & Marine Engineering, Volume 3; https://doi.org/10.30564/hsme.v3i2.3837
This study is based on the hypothesis that the implementation of Integrated Water Resources Management (IWRM) tools in the Oueme watershed has not led to a systematic improvement in the degree of IWRM implementation in the Oueme Valley in Benin. Methodologically, data were collected through a semi-structured survey of stakeholder families in the study area using snowball sampling. The tool used was the form developed by the United Nations to collect data to assess the level of IWRM implementation. The four (4) assessment criteria, each covering a key component of IWRM, are the enabling environment, institutions and participation, management tools and financing. The results obtained per criteria according to the stepwise methodology adopted reveal on average a degree of implementation of 40 on a scale of 0 to 100 in the Oueme basin. This value varies according to the geographical area and the factors considered. This study, which is a decision-making tool, provides a guide for governments to monitor the progress of integrated water resources management in their territory.
Hydro Science & Marine Engineering, Volume 3; https://doi.org/10.30564/hsme.v3i2.3834
Spur dykes also known as Groynes are often used to either divert or attract the flow from the main structure to safeguard their life. Those structures may be bridge piers, abutments or any similar hydraulics structures. Spur dykes are also used to save the cutting of banks on concave side of stream. Lots of work have been done in recent past on spur dykes by many investigators in which various hydraulic and geometrical parameters of spur dykes such as discharge, sediment size, flow velocity, shear stress, spur dykes shape, size and submergence etc. are studied in detail. But mostly all the studies were pointed out in straight open channels. Very few studies were done in curved channel and only their similar effects were studied. In present thesis main emphasis is given to study the effect of orientation and location of spur dykes in meandering channel on the bed of downstream side. In the present study experimental work has been carried out in 80° bend and constant discharge (Q = 4.5 l/s) is allowed to pass in channel without spur dyke. It is found that maximum scouring occurs at angular displacement θ = 60° to 80° in the vicinity of outer bank. To minimize this scouring, spur dyke has been installed at angular displacement θ = 20°, 40° & 60° by changing the dyke angle α = 60°, 90° & 120° respectively. It is found that scouring at θ = 60° is reduced by installing spur dyke at angular displacement θ = 40° which is oriented at α = 60° and scouring at θ = 80° is reduced by installing spur dyke at angular displacement θ = 60° which is oriented at α = 60°.
Hydro Science & Marine Engineering, Volume 3; https://doi.org/10.30564/hsme.v3i2.4121
Surface water samples were collected from selected locations along river Panchaganga, from Kolhapur to Narsobawadi during April 2019. Physicochemical parameters were determined in the laboratory and chemical mass balance approach was adopted to estimate the individual ionic loads in the river water. Streeter-Phelps equation was applied to derive a relationship between DO and BOD5. Model parameters such as De-oxygenation Rate (Kd) and Re-aeration Rates (Kr ) were optimized using different empirical methods. The result of chemical mass balance showed an increase in the loading of various ions from upstream to downstream which could be attributed to agricultural and industrial wastes that enter the main stream. De-oxygenation rate and re-aeration constants were calculated using various empirical methods. DO sag curve was developed using Streeter Phelp’s model and compared with the observed parameters which showed a significant correlation. DO-BOD concentration observed along the course of the river indicated that the self-purification capacity of the river is high due to which the river regains the lost DO level at a distance less than 50 meters.