Faculty Publications
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Item Effect of emerged coastal vegetation on wave attenuation using open source CFD tool: REEF3D(Springer, 2019) Hunasanahally Sathyanarayana, H.S.; Suvarna, P.; Abhijith, P.A.; Prabhu, A.S.; Umesh, U.; Kamath, A.Coastal vegetation is a soft solution for protecting the coast from the action of waves by attenuating the wave height and reducing the energy of the waves. Effect of wave height attenuation as a result of the presence of emerged coastal vegetation is studied numerically by resolving the Reynolds-averaged Navier–Stokes (RANS) equations. A three-dimensional numerical wave tank model is simulated using an open source computational fluid dynamics (CFD) software REEF3D, and wave attenuation due to emerged coastal vegetation is determined. An artificial, rigid, emerged vegetation for a length of 2m is developed in a numerical wave tank of REEF3D. The model is tested for regular waves of height 0.08, 0.12, and 0.16 m and wave periods of 1.8 and 2 s in a water depth of 0.40 and 0.45 m. The wave heights are measured at different locations along the vegetation meadow at 0.5 m intervals. The devolved numerical model is corroborated by comparing the obtained numerical results with the experimental results as reported by John et al. (Experimental investigation of wave attenuation through artificial vegetation meadow, ISH—HYDRO, [1]). The numerically obtained results are concurrent with the experimental results. © Springer Nature Singapore Pte Ltd. 2019.Item An experimental study to evaluate the warpage and cracking issues in fused deposition modeling(Pleiades journals, 2019) Suhas, A.; Rajpal, R.; Gangadharan, K.V.; Umesh, U.Research in 3D printing technology is growing immensely because of the advantage of manufacturing complex shapes in less time as compared to conventional manufacturing processes. However, warpage and cracking are the critical issues in fused deposition modeling technique which results in a reduction in the strength of the component. This paper aims to address the root causes for reducing the warpage and cracking in a 3D printed component. Fused-deposition-modeling-based 3D printer is used in this study to manufacture the samples. The behavior of warpage and cracking in the specimens are studied by altering bed temperature and extrusion width of the filament. The experimental results revealed that printing a component at 100 °C and 0.75 mm extrusion width led to minimum warpage and no crack condition. © Springer Nature Singapore Pte Ltd. 2019.Item Surface Soil Moisture Retrieval Using C-Band Synthetic Aperture Radar (SAR) over Yanco Study Site, Australia—A Preliminary Study(Springer, 2020) Gururaj, G.; Umesh, U.; Shetty, A.The motto of this work is to evaluate retrieval of surface soil moisture (5 cm) using Sentinel-1a C-band data Synthetic Aperture Radar (SAR). Data for this study is collected from Yanco Study site, Australia. Yanco study site consists of 37 soil moisture measuring stations at every 20 min interval for various soil depths and it also provides other Hydro-Meteorological information. SAR backscattered energy is a function of soil roughness and soil moisture. Surface roughness is eliminated using change detection approach. The R2 performance statistics revealed that between Backscattered energy and NDVI there is no relation. Volumetric soil moisture and backscattered energy showed a positive correlation with R2 = 0.57 and 0.43 for VH and VV polarization. Dielectric constant also showed a positive correlation with backscattered energy having R2 = 0.62 and 0.38 for VH and VV polarization respectively. By taking into account of all these affecting parameters, a regional Semi-empirical model is developed to retrieve surface Soil moisture over the study area. © Springer Nature Singapore Pte Ltd. 2020.Item IoT Based Joystick Controlled Pibot Using Socket Communication(Institute of Electrical and Electronics Engineers Inc., 2018) Radhika, K.A.; Raksha, B.L.; Sujatha, B.R.; Umesh, U.; Gangadharan, K.V.The Internet of things (IoT) and automated frameworks is a key driver of robotic development technology. In current technology, robots are controlled using Smartphone. In our approach Driving Force GT Joystick is used to control the robot wirelessly and which provide precise manual control on a robotic vehicle. Compared to web-controlled or Smartphone controlled Pibot, joystick controlled Pibot is more effective since it provides speed control. In this work, Raspberry Pi is used as a base controller to control robotic car called Pibot to work as real-time system and vehicle operations are controlled remotely at the ground station using USB joystick. The camera on the Pibot is used for live video streaming on a webpage using HTTP server for surveillance. The server-client socket communication (via strong Wi-Fi) is performed for controlling the vehicle in the remote station using python programming. © 2018 IEEE.Item Development of Smart Drip Irrigation System Using IoT(Institute of Electrical and Electronics Engineers Inc., 2018) Math, A.; Ali, L.; Umesh, U.India is a country with agriculture having paramount significance. Hence it is important to irrigate the plants in an astute way to get good production by maximizing the yield per unit space. Irrigation is the supply of an appropriate amount of water to the plants at a precise time. The objective of this endeavour is to irrigate the plants using the smart drip irrigation system within National Institute of Technology Karnataka campus. To achieve this, open source platform is used as a central controller of the system. Various sensors have been employed which continuously provide the existing parameters of factors governing healthiness of plants. Based on the information obtained from the RTC module water is supplied to the plants at regular interval of time by controlling a solenoid valve. The entire irrigation system can be monitored and managed by the webpage. This web page has a facility for controlling the irrigation of plants, both in manual and automatic fashion. The health of the plants is monitored by a raspberry pi camera which gives live streaming to the webpage. Water flow sensor accords information about water flow to the controller by the means of wireless communication. This information is analyzed by the controller to find out leakages in the pipe. Further, weather prediction is carried out, so as to regulate the quantity of water being administered thus making it more reliable and efficient. © 2018 IEEE.Item Assessment of spatial variation of soil moisture during maize growth cycle using SAR observations(SPIE spie@spie.org, 2019) Gururaj, P.; Umesh, U.; Shetty, A.Spatial Information about Soil moisture over agricultural crops are required for efficient irrigation which in turn helps in saving water and increases crop yield. Soil moisture also useful in prediction of flooded and drought regions. However field measurement of soil moisture is not a practical approach. The main objective of the study is to track soil moisture variation all along the maize growth period in a Semi-Arid region. There are only few studies carried out on soil moisture variation considering whole maize growing period. During the crop growing period soil moisture field investigation are conducted in synchronization with Satellite pass. Sentinel-1a Synthetic Aperture RADAR (SAR) satellite, Interferometric wide swath dual polarized data with 5.405 GHz frequency and central incidence angle of 23ï?° with repeat period of 12 days was used in this study. All in all during growth period 6 satellite pass scenes are acquired and processed by standard procedure using Sentinel Application Platform (SNAP) software. An attempt was made to redeem surface soil moisture for the whole maize growing crop cycle using water cloud model. The whole period of maize crop was divided into 3 parts like seedling, growing and harvesting period and soil moisture is retrieved for each period. The estimated soil moisture was validated with 30 field measured soil moisture samplings. The correlation coefficient of retrieved and actual soil moisture of seedling, growing and harvesting periods are 0.77, 0.72 and 0.6 respectively. The output of this study will be helpful in formulating strategies for irrigation water management. © 2019 SPIE.Item A QGIS Plug-in for Processing MODIS Data(Institute of Electrical and Electronics Engineers Inc., 2019) Aishwarya Hegde, A.; Umesh, U.; Shetty, A.In the past few decades number of Earth-observing satellites are continuously gathering information and only about 10 percent of the information is utilized by the users. With so much accessible information the researchers have not explored the datasets completely as there is absence of effective tool to process the information. MODIS data sensors have accessible data at various temporal and spatial resolutions. To productively use these datasets in open-source GIS programming like QGIS, there is a need to pre-process the dataset using a plug-in. The plug-in is built using python and PyQt interface for QGIS.The plug-in operates on MODIS Data (Terra/Aqua/Combined) computerizes and process the functionalities for MODIS products like MOD11, MOD09, MOD21. The processed datasets can be largely used in investigation of time series analysis for some earth resource application. © 2019 IEEE.Item Static Fire Risk Index for the Forest Resources of Karnataka(Institute of Electrical and Electronics Engineers Inc., 2019) Konkathi, P.; Shetty, A.; Venkatesh, V.; Yathish, P.H.; Umesh, U.Forest fires are the major cause of degradation of forest. Forest fires have caused substantial damage in the state of Karnataka in terms of economic, social, environmental impacts on humans and also loss of biodiversity. Fire risk indices are important tools for the management of forest fires. They are developed based on static and/or dynamic factors influencing the occurrence of fire and propagation of fire. The objective of the present study was to develop a new static fire risk index based on parameters influencing forest fire such as fuel type, elevation, slope, aspect, terrain ruggedness, proximity to a road, proximity to water bodies and proximity to settlements. MODIS Land cover type yearly L3 global 500m SIN grid(MCD12Q1) was used to compute fuel type index based on historical fire data, SRTM DEM was used to compute slope index, aspect index, elevation index, and terrain ruggedness index. Road index, settlement index, and water body index were developed from the proximity maps generated. A geographic information system (GIS) was utilized adequately to join diverse forest fire causing factors for demarcating static fire risk index. The evaluated exactness was around 87%, i.e., the developed GIS-based static fire risk index of the examination zone was observed to be in solid concurrence with actual fire affected regions. The study area exhibited 32.38% prone to fire risk. © 2019 IEEE.Item Numerical investigation on wave transmission characteristics of perforated and non-perforated pile breakwater(Institute of Physics Publishing helen.craven@iop.org, 2019) Rao, N.; Rao, P.; Nayak, K.; Kishor Pal, S.; Hunasanahally Sathyanarayana, A.; Suvarna, P.; Umesh, U.Dock operations, harbouring and many other port activities demand tranquil water condition. This makes breakwater structures more than essential in coastal engineering applications. For zero wave action, rubble mound or vertical wall breakwaters are used, and for small docks and shores, piles can be used as efficient breakwaters. The permeability of pile breakwaters also aides in keeping the shores clean as there is water circulation and keeps the interferences caused due to littoral drift to the minimum. Numerical study on the single row pile breakwater is carried out using an open source computational fluid dynamics (CFD) software REEF3D. Interaction of waves with non-porous pile breakwater is simulated in a three-dimensional numerical wave tank using REEF3D and resulted transmission coefficient is validated using the physical model studies as reported by Subba Rao et al. (1999). Further, the efficiency of porous piles over non-porous piles is studied by simulating wave conditions by varying wave height, wave period, water depth and percentage porosity of the piles. It has been observed from the present study that porous piles are more efficient in wave attenuation compared to non-porous piles. The reason is that perforations increase turbulence during wave interaction which results in a better wave attenuation. © Published under licence by IOP Publishing Ltd.Item Study on shelter effect of solid wind fences(2011) Umesh, U.; Prashanth, J.; Yaragal, S.C.; Nagaraj, M.K.In this paper the shelter effect of solid wind fence is investigated. A solid fence was considered with different bottom gap ratios (ratio of bottom gap to the height of the fence) of 0, 0.1, 0.2 and 0.3. The numerical analysis was done for different free stream velocities of 7.5 m/s, 10 m/s and 12.5 m/s. The results obtained were compared with the results of wind tunnel testing and flow visualization. Comparison between the experimental and numerical results showed a fairly good agreement. Flow visualization technique provided sufficient information for planning and conducting flow field measurements with a clear demarcation of reattachment length. The modified k- ? turbulence model predicted the flow well. From both the experimental and numerical investigation it is shown that a fence with gap ratio of 0.1 is effective in providing good shelter effect. © 2011 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.