Dr. Ellora Padhi

 

Brief Details:

Dr. Ellora Padhi is working as an Assistant Professor, Department of Civil Engineering, Shiv Nadar Institution of Eminence (SNIoE), Greater Noida since January 2021. Prior to joining SNIoE, she worked as a Research Associate in the Department of Civil Engineering, IIT Kharagpur for almost one year. From the educational front, she completed her B.Tech. in Civil Engineering from College of Engineering Bhubaneswar, Biju Pattanaik University of Technology, Odisha in 2010. Then, she earned her M. Tech in Water Resources Engineering from NIT Rourkela in 2014. Thereafter, she joined Department of Civil Engineering, IIT Kharagpur to pursue a Ph.D. in Hydraulics and Water Resources Engineering specialization. Her Ph.D. tenure was completed in January 2020. Her thesis title was “Turbulence characteristics in water-worked and screeded gravel-bed streams”. Her research interest includes turbulence in open channel, sediment transport processes, and analysis of rapidly varied flow. In 2022, she has received Start-up Research Grant of Rs. 21 Lakhs from SERB for her project titled “A novel hybrid approach for the design of stilling basin to counter the downstream local scour”. Dr. Ellora has published articles in many leading journals, such as Physics of Fluids, Journal of Hydraulic Engineering, Proceedings of Royal Society, Journal of Hydraulic Research, etc. So far, she has published 18 research articles and 7 conference proceedings. She has been a reviewer of Journal of Fluid Mechanics, Journal of Hydraulic Engineering, Journal of Hydraulic Research, International Journal of Sediment Research, Physics of Fluid, Journal of Geophysical Research, etc.

Research

Turbulent flow over a gravel bed is one of the important topics of discussion due to its intricate behaviour in the near bed flow zone. Near the bed, the flow is highly influenced by the fluid-gravel interactions and becomes nonhomogeneous within the reach. To replicate the flow characteristics of a natural river in the laboratory, it is vital to recapture the bed condition of a natural river to ensure the accurate representation of riverbed. However, in the laboratory, it is very common to create the bed by placing the mixture of gravels randomly in the flume and then screeded manually. Such a bed is quite different from the bed observed in a natural gravel bed river. In a natural stream, continuous erosion and deposition of gravels occur owing to repetitive floods. As a result, a sedimentary bed roughness structure is created by the flowing water, and such a bed is commonly termed water-worked gravel-bed (WGB). It is observed that change in bed roughness has a significant impact on the velocity profiles. However, the effects of bed roughness on the near-bed flow characteristics are still to be explored. Hence, to understand the impact of water action on the near-bed flow properties, we tried to examine the double-averaged (DA) turbulence characteristics over both WGB and SGB by using two-dimensional particle image velocimetry (PIV). Owing to the water action, it was observed that the orientation, as well as the alignment of the surface grains, were changed. The major axis of the gravels was oriented along the streamwise direction which guides the flow to be streamlined, especially in the near-bed flow zone. Analysis of the lateral vorticity contours illustrated that owing to the presence of the gravels, there exists a counter-rotating fluid motion. Besides, analysis of the DA streamwise velocity, spatially averaged (SA) Reynolds and dispersive shear stress, SA TKE fluxes, etc., were carried out. Result analysis showed that the near-bed flow characteristics are highly affected by the gravel roughness; however, in the main flow layer, their effects are insignificant. Comparison study infers that the magnitude of flow characteristics is higher in case of WGB than that of SGB even for identical Froude numbers.

Teaching: 

Hydraulic jumps are common and fascinating hydraulic phenomena observed in open channel flows, offering crucial insights into the complex interactions between fluid and channel geometry. This abstract presents a concise overview of hydraulic jumps, the types of hydraulic jumps based on Froude number and tailwater depth, their characteristics, and their significance in various engineering and environmental contexts. A hydraulic jump occurs when supercritical flow abruptly transitions to subcritical flow within an open channel. This phenomenon is characterized by sudden changes in flow velocity, depth, and energy dissipation, leading to distinctive features such as turbulent rollers, and free-surface fluctuations. Understanding hydraulic jumps is vital in a wide range of applications, including river engineering, dam spillways, irrigation canals, etc. Further, hydraulic jumps play a crucial role in preventing erosion, managing sediment transport, and ensuring the efficient operation of hydraulic structures.

Google Scholar Link:

https://scholar.google.com/citations?user=OYK7sU0AAAAJ&hl=en