Abhijit Lade - Academia.edu (original) (raw)
Papers by Abhijit Lade
River Research and Applications
Water Supply
Flow in streams and rivers typically erodes the banks, causing channel bank migration laterally, ... more Flow in streams and rivers typically erodes the banks, causing channel bank migration laterally, resulting in loss of nearby land, modification in channel morphology, excessive sediment transport, and water quality degradation. A spur dike is a hydraulic structure placed at the channel bank projecting outward to guide or divert the flow away from the bank, thus protecting it from erosion. The stability of the riverbed and banks is influenced by turbulent characteristics such as three-dimensional velocity distribution, turbulent kinetic energy, Reynolds shear stress, turbulent intensity, and bed shear stress. The researchers found that these turbulence parameters are instrumental in sediment movement along the channel's bed and from its banks. Spurs dikes are a significant river training structure provided along the river bank to protect from erosion. Several aspects related to spur dikes, such as their geometry, physical features, design considerations, flow and scour patterns, ...
Piano Key (PK) Weirs are non gated type of weirs with increased discharge capacity because of the... more Piano Key (PK) Weirs are non gated type of weirs with increased discharge capacity because of their increased plan length. PK weirs are better than other conventional types of weirs for applications where the channel width is restricted. These are cost effective hydraulic structures and can work efficiently at low heads also. In this paper, two physical PK weir models with different sill geometries were tested; one with sloping sill and the other with triangular sill. Based on the experimental results, it has been found that the discharge coefficient (Cd) for sloping sill and triangular sill are 0.243 and 0.264 respectively. The said modifications don’t exhibit remarkable improvement in coefficient of discharge as compared to the regular PK weir, but can have greater efficiency for higher discharges. Finally, suggestions regarding different shapes of sill walls of PK weir such as sloping and triangular sills compared with existing plain crest without any sill are presented in the end.
Today, the consumption of Ready Mix Concrete (RMC) is rapidly increasing in India owing to the ra... more Today, the consumption of Ready Mix Concrete (RMC) is rapidly increasing in India owing to the rapid growth in Infrastructural and Real Estate sectors. Supplying concrete with desired quality consistently has become a great challenge for the RMC suppliers. Hence, the evaluation as well as monitoring the quality of RMC production is critical. this paper is an attempt to a apply the Six Sigma DMAIC approach to a RMC Plant in Chakhan, Pune. The sigma level of the existing plant has been evaluated. Also the production is Statistically analyzed using various tools such as X bar chart and R charts and the process capability index has also been reported. © 2015 Elixir All rights reserved. ARTICLE INFO Article history: Received: 5 July 2015; Received in revised form: 1 August 2015; Accepted: 10 August 2015;
The effect of a channel pit on the turbulence structure around an embedded cylinder was explored ... more The effect of a channel pit on the turbulence structure around an embedded cylinder was explored based on the behaviour of high-order moments of streamwise velocity fluctuations. Instantaneous velo...
The invention of Geo-polymers has paved the way for construction industry to use Fly ash based Ge... more The invention of Geo-polymers has paved the way for construction industry to use Fly ash based Geo-Polymer Concrete with 100 % replacement of cement. Substantial experimental research has been conducted ever since on Geo-Polymer concrete which can prove to the sustainable construction material of the future. This paper reviews various materials used for manufacturing this concrete such as alkaline liquids, fly ash, aggregates and super-plasticizers. The experimental investigations conducted by various researchers on the aspects such as mix design, curing etc. and their impact on properties of Geo-polymer concrete has also been reported. Finally, concluding remarks and suggestions regarding the applications of Geo-polymer concrete are delineated at the end.
Alluvial channels with sinuosity follow an altered flow behavior, contradictory to straight flows... more Alluvial channels with sinuosity follow an altered flow behavior, contradictory to straight flows. At the interface of surface water and groundwater, seepage is a significant phenomenon occurring at the boundary of alluvial channels. The study of turbulence in seepage affected sinuous alluvial channels would thus provide us with a better insight into their hydro-morphological behavior. To address the nature of turbulence in sinuous channel with downward seepage an experimental framework was design. The paper reports the structure of turbulence in the sinuous channel for no seepage and seepage flow. With downward seepage, there is a noticeable shift of Reynolds shear stress at near-bed, which reports more momentum transport. The average streamwise and transverse turbulence intensity increased by 3.8–18.5% and 4–10.6%, respectively with downward seepage. Calculation of Kolmogorov complexity and the Kolmogorov complexity spectrum suggests higher randomness in the outer region, which ca...
Engineering Research Express
Extraction of sand from riverbed has catastrophic repercussions on aquatic animalia habitat, wate... more Extraction of sand from riverbed has catastrophic repercussions on aquatic animalia habitat, water quality, and the environment. Alongside, physical alterations in the fluvial hydraulics arising on account of sand mining are also worthy of attention. Flows passing over the pits excavated in a channel have enhanced erosive propensity, which can be a cause of concern for the downstream hydraulic structures. The complex nature of flow interacting with the bridge piers after passing over a mining pit is not fully understood. Experiments were conducted to apprehend the effects of a dredged pit on the turbulence flow-field around an oblong pier. Flow was passed in an erodible sand bed rectangular channel having an oblong pier for the first case. In the second case, a pit was dredged in the mobile bed to replicate a mined channel, and the pier was subjected to the same discharge. The streambed at the approach of the pier experiences greater mean bed shear because of dredging. The amplifica...
Sedimentation in reservoirs, which eventually leads to detrimental loss of storage capacity, is o... more Sedimentation in reservoirs, which eventually leads to detrimental loss of storage capacity, is one of the most serious problems in dam engineering. In this paper, problems faced by Run-of-River schemes in the Himalayan region due to sedimentation are highlighted. Three general strategies for addressing reservoir sedimentation currently utilized are: reduction of incoming sediments, minimization of sediment deposition, and removal of sediments from the reservoir. This paper addresses the feasibility of reservoir sluicing for abating the sediment deposition near the power intake and simultaneously maintaining the minimum water level required for power generation in Run-of-River schemes. A brief overview of the factors governing the efficiency of sluicing operations, studied till date has been presented in this paper. In addition to this, the procedures and results obtained by physical model tests on sluicing operations carried out till now have also been illustrated. The various phys...
Water Resources Management and Reservoir Operation
River Research and Applications
Proceedings of the Institution of Civil Engineers - Water Management
Water
Sand mining in an active alluvial channel can compromise the streambed stability of the hydraulic... more Sand mining in an active alluvial channel can compromise the streambed stability of the hydraulic structures nearby. This experimental study is aimed at investigating the effects of rectangular mining pit on the morphodynamics around circular tandem piers in a movable bed. A rectangular pit is excavated upstream of two circular piers embedded in the sand-bed in a tandem arrangement. The results are then compared to a case having only the piers without any mining pit. Turbulent stresses and mean velocities in the near-bed region rise significantly at the upstream region of the piers in the presence of a pit. Also, stronger flow reversal and horseshoe vortices have been detected at the base of the pier front. Due to these alterations in the nature of turbulence, erosion of channel beds upstream of the piers, increased scour depths, scour volume, and lateral erosion of the scour hole have been observed. Dynamic evolution of the local scour at various time scales has been studied using ...
Physica A: Statistical Mechanics and its Applications
River Research and Applications
Water Supply
Flow in streams and rivers typically erodes the banks, causing channel bank migration laterally, ... more Flow in streams and rivers typically erodes the banks, causing channel bank migration laterally, resulting in loss of nearby land, modification in channel morphology, excessive sediment transport, and water quality degradation. A spur dike is a hydraulic structure placed at the channel bank projecting outward to guide or divert the flow away from the bank, thus protecting it from erosion. The stability of the riverbed and banks is influenced by turbulent characteristics such as three-dimensional velocity distribution, turbulent kinetic energy, Reynolds shear stress, turbulent intensity, and bed shear stress. The researchers found that these turbulence parameters are instrumental in sediment movement along the channel's bed and from its banks. Spurs dikes are a significant river training structure provided along the river bank to protect from erosion. Several aspects related to spur dikes, such as their geometry, physical features, design considerations, flow and scour patterns, ...
Piano Key (PK) Weirs are non gated type of weirs with increased discharge capacity because of the... more Piano Key (PK) Weirs are non gated type of weirs with increased discharge capacity because of their increased plan length. PK weirs are better than other conventional types of weirs for applications where the channel width is restricted. These are cost effective hydraulic structures and can work efficiently at low heads also. In this paper, two physical PK weir models with different sill geometries were tested; one with sloping sill and the other with triangular sill. Based on the experimental results, it has been found that the discharge coefficient (Cd) for sloping sill and triangular sill are 0.243 and 0.264 respectively. The said modifications don’t exhibit remarkable improvement in coefficient of discharge as compared to the regular PK weir, but can have greater efficiency for higher discharges. Finally, suggestions regarding different shapes of sill walls of PK weir such as sloping and triangular sills compared with existing plain crest without any sill are presented in the end.
Today, the consumption of Ready Mix Concrete (RMC) is rapidly increasing in India owing to the ra... more Today, the consumption of Ready Mix Concrete (RMC) is rapidly increasing in India owing to the rapid growth in Infrastructural and Real Estate sectors. Supplying concrete with desired quality consistently has become a great challenge for the RMC suppliers. Hence, the evaluation as well as monitoring the quality of RMC production is critical. this paper is an attempt to a apply the Six Sigma DMAIC approach to a RMC Plant in Chakhan, Pune. The sigma level of the existing plant has been evaluated. Also the production is Statistically analyzed using various tools such as X bar chart and R charts and the process capability index has also been reported. © 2015 Elixir All rights reserved. ARTICLE INFO Article history: Received: 5 July 2015; Received in revised form: 1 August 2015; Accepted: 10 August 2015;
The effect of a channel pit on the turbulence structure around an embedded cylinder was explored ... more The effect of a channel pit on the turbulence structure around an embedded cylinder was explored based on the behaviour of high-order moments of streamwise velocity fluctuations. Instantaneous velo...
The invention of Geo-polymers has paved the way for construction industry to use Fly ash based Ge... more The invention of Geo-polymers has paved the way for construction industry to use Fly ash based Geo-Polymer Concrete with 100 % replacement of cement. Substantial experimental research has been conducted ever since on Geo-Polymer concrete which can prove to the sustainable construction material of the future. This paper reviews various materials used for manufacturing this concrete such as alkaline liquids, fly ash, aggregates and super-plasticizers. The experimental investigations conducted by various researchers on the aspects such as mix design, curing etc. and their impact on properties of Geo-polymer concrete has also been reported. Finally, concluding remarks and suggestions regarding the applications of Geo-polymer concrete are delineated at the end.
Alluvial channels with sinuosity follow an altered flow behavior, contradictory to straight flows... more Alluvial channels with sinuosity follow an altered flow behavior, contradictory to straight flows. At the interface of surface water and groundwater, seepage is a significant phenomenon occurring at the boundary of alluvial channels. The study of turbulence in seepage affected sinuous alluvial channels would thus provide us with a better insight into their hydro-morphological behavior. To address the nature of turbulence in sinuous channel with downward seepage an experimental framework was design. The paper reports the structure of turbulence in the sinuous channel for no seepage and seepage flow. With downward seepage, there is a noticeable shift of Reynolds shear stress at near-bed, which reports more momentum transport. The average streamwise and transverse turbulence intensity increased by 3.8–18.5% and 4–10.6%, respectively with downward seepage. Calculation of Kolmogorov complexity and the Kolmogorov complexity spectrum suggests higher randomness in the outer region, which ca...
Engineering Research Express
Extraction of sand from riverbed has catastrophic repercussions on aquatic animalia habitat, wate... more Extraction of sand from riverbed has catastrophic repercussions on aquatic animalia habitat, water quality, and the environment. Alongside, physical alterations in the fluvial hydraulics arising on account of sand mining are also worthy of attention. Flows passing over the pits excavated in a channel have enhanced erosive propensity, which can be a cause of concern for the downstream hydraulic structures. The complex nature of flow interacting with the bridge piers after passing over a mining pit is not fully understood. Experiments were conducted to apprehend the effects of a dredged pit on the turbulence flow-field around an oblong pier. Flow was passed in an erodible sand bed rectangular channel having an oblong pier for the first case. In the second case, a pit was dredged in the mobile bed to replicate a mined channel, and the pier was subjected to the same discharge. The streambed at the approach of the pier experiences greater mean bed shear because of dredging. The amplifica...
Sedimentation in reservoirs, which eventually leads to detrimental loss of storage capacity, is o... more Sedimentation in reservoirs, which eventually leads to detrimental loss of storage capacity, is one of the most serious problems in dam engineering. In this paper, problems faced by Run-of-River schemes in the Himalayan region due to sedimentation are highlighted. Three general strategies for addressing reservoir sedimentation currently utilized are: reduction of incoming sediments, minimization of sediment deposition, and removal of sediments from the reservoir. This paper addresses the feasibility of reservoir sluicing for abating the sediment deposition near the power intake and simultaneously maintaining the minimum water level required for power generation in Run-of-River schemes. A brief overview of the factors governing the efficiency of sluicing operations, studied till date has been presented in this paper. In addition to this, the procedures and results obtained by physical model tests on sluicing operations carried out till now have also been illustrated. The various phys...
Water Resources Management and Reservoir Operation
River Research and Applications
Proceedings of the Institution of Civil Engineers - Water Management
Water
Sand mining in an active alluvial channel can compromise the streambed stability of the hydraulic... more Sand mining in an active alluvial channel can compromise the streambed stability of the hydraulic structures nearby. This experimental study is aimed at investigating the effects of rectangular mining pit on the morphodynamics around circular tandem piers in a movable bed. A rectangular pit is excavated upstream of two circular piers embedded in the sand-bed in a tandem arrangement. The results are then compared to a case having only the piers without any mining pit. Turbulent stresses and mean velocities in the near-bed region rise significantly at the upstream region of the piers in the presence of a pit. Also, stronger flow reversal and horseshoe vortices have been detected at the base of the pier front. Due to these alterations in the nature of turbulence, erosion of channel beds upstream of the piers, increased scour depths, scour volume, and lateral erosion of the scour hole have been observed. Dynamic evolution of the local scour at various time scales has been studied using ...
Physica A: Statistical Mechanics and its Applications