August 2025 : Open position for a Ph.D. student

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Machine Learning-Augmented Flow Field Analysis in Evaporating Droplets using Particle Image Velocimetry

Droplet impact and evaporation on solid surfaces play a central role in diverse applications, including inkjet printing, surface coating, thermal management, and biomedical assays. Gaining insight into the internal flow dynamics of evaporating droplets, particularly in the presence of colloidal particles, is key to controlling deposition patterns and understanding coupled transport phenomena. This project focuses on conducting Particle Image Velocimetry (PIV) experiments to visualize and quantify fluid flow within evaporating droplets on solid substrates. Alongside the experimental work, machine learning (ML) techniques will be introduced to enhance data interpretation and uncover hidden patterns in complex flow fields. The ML component includes (i) Flow Pattern Classification: Using supervised learning to identify and classify flow regimes (e.g., radial flow, Marangoni convection) from PIV-derived velocity fields. (ii) Velocity Field Denoising: Employing convolutional neural networks (CNNs) to enhance noisy or incomplete velocity data. This combined approach aims to shed light on the interaction between evaporation-induced flows, solutal Marangoni effects, and thermocapillary convection during the evaporation of water–alcohol mixtures. The intern will gain hands-on experience in experimental fluid dynamics, data analysis, and the integration of machine learning techniques in experimental fluid mechanics. PIV facility is funded by ANRF, New Delhi.

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Research Overview

Our lab focuses on two core research areas: Droplets and Interfaces and Fluid-Structure Interaction (FSI). In both domains, we combine advanced computational modeling with state-of-the-art experimental techniques to explore fundamental and applied problems in fluid mechanics.

Droplets and Interfaces:
We study the dynamics of droplet impact and evaporation on solid surfaces, design of bioinspired microtextured surfaces for controlled droplet bouncing, formation of “coffee-ring” colloidal deposits, and particle sorting through evaporation-driven flows. We are also interested in understanding dynamic wetting behavior near the contact line. To investigate these phenomena, we use high-speed imaging, infrared thermography, and Particle Image Velocimetry (PIV), among other diagnostic tools. Experimental findings are complemented and validated using simulations from our in-house finite element solver.

Fluid-Structure Interaction (FSI):
Our FSI research integrates both numerical and experimental approaches. On the computational side, we develop and use methods such as the immersed boundary technique to simulate complex fluid–structure interactions. Experimentally, we perform laser-based displacement measurements, hot-wire anemometry, and other techniques to study the coupled dynamics of fluids and flexible structures. One of our ongoing interests includes measuring energy harvesting capabilities of piezoelectric membranes in fluid environments.

Our lab welcomes collaboration and engagement from researchers, students, and industry partners interested in interdisciplinary fluid mechanics problems.

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Contact us: 

Prof. Rajneesh Bhardwaj, 

Room S36 (second floor) Department of Mechanical Engineering,

Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India. 

e-mail: rajneesh.bhardwaj [AT] iitb.ac.in