Curriculum Vitae
Assistant Professor, IIT Delhi
PhD: IISc Bangalore
PostDoc: DAMTP Cambridge, and
Weizmann Institute of Science

I am an Assistant Professor in the Department of Applied Mechanics at IIT Delhi. Previously, I was a PBC VATAT Postdoctoral Fellow at the Weizmann Institute of Science, Israel, working with Prof. Victor Steinberg on flow instabilities in complex fluids. Prior to that, I was a postdoc at the University of Cambridge, exploring air curtains for energy-efficient buildings with Prof. Paul Linden. My PhD at IISc Bangalore focused on two-phase turbulent flows under Prof. R. N. Govardhan.

Our research group, FE²B at IIT Delhi, focuses on diverse topics, including air curtain mixing dynamics, vortex ring-droplet interactions, bio-fluidic models for cancer cell hemodynamics, underwater acoustic signatures, dry granular mass flow, energy extraction via vortex-induced vibrations, air pollution and IAQ in building ventilation, drag reduction for green shipping, viscoelastic channel flow turbulence, and numerical modeling of vortex-induced vibrations in dam gates. We aim to address fundamental and applied challenges in fluid mechanics across environmental, biological, and engineering contexts.

I strongly encourage dedicated students to contact me for their Masters or PhD study. My lab (Fluids lab for Environment, Engineering, and Biology: FE²B) focuses on Understanding Turbulence For Societal And Industrial Need: Two phase, Stratified And Elastic flows. We are basically a group of experimental enthusiasts interested in solving fluid dynamics problems. Interested students are encouraged to contact me personally at narsingjha@am.iitd.ac.in.

Research

Purely elastic instability in plane Poiseuille flow

To investigate elastic instabilities in polymeric flows, I use a 2D channel with a 7:1 aspect ratio, 0.5 mm height, and a length of 1000 heights. Pressure drop measurements, Laser Doppler Velocimetry (LDV), and Particle Image Velocimetry (PIV) are employed to study drag and velocity. I observe elastic waves, nonlinear breakdowns leading to elastic turbulence, and coupling between elastic waves and turbulent states. By analyzing wall friction and flow instabilities across varying Weissenberg numbers (Wi = polymer relaxation time/flow time), I identify distinct flow states and transitions, advancing my understanding of elastic turbulence and turbulent drag reduction mechanisms.

Effect of human passage on air curtain sealing in the doorways of a building

Air curtains minimize heat and mass exchange between cold and warm environments, reducing energy loss and improving comfort. Laboratory experiments studied the impact of a person passing through the curtain, showing decreased effectiveness with increased walking speed. Using dye visualization and time-resolved particle image velocimetry, we examined flow structure and entrainment caused by the curtain-wake interaction, finding the effect independent of travel direction. The feasibility for hospital room containment was evaluated, comparing lab results with real-scale measurements, Fluent simulations, and theoretical models. Additionally, we analyzed the impact of heavier curtain fluids on air curtain stability and effectiveness.

Origin of thin film circular hydraulic jump

I have also worked on experimental investigation of the unsteady behavior of circular and two dimensional hydraulic jump and developed a theoretical model. Surfactant, Acetic-acid, and Propanol are separately mixed in water to vary the surface tension and viscosity of the liquid so that we could study the effect of fluid properties on hydraulic jump.

Interaction of bubbles with vortical structures

Bubbly turbulent flows involve complex interactions between bubbles and turbulence, influencing both bubble dynamics and flow structures. This thesis explores these interactions in three parts. First, the interaction of a single bubble with a vortex ring in water is studied as a simplified model of bubble-vortex interactions in turbulence. Next, single-bubble interactions in fully developed turbulent channel flows are examined. Finally, the dynamics of numerous bubbles injected into turbulent channels are investigated. Bubble motion and deformation are analyzed using high-speed visualization, while time-resolved Particle Image Velocimetry (PIV) and pressure drop measurements provide insights into the surrounding flow fields and turbulence modulation.

Super-hydrophobic surfaces for drag reduction

I have also worked on the sustainability of air pockets in the crevices on super-hydrophobic surface by controlling the air saturation level of the incoming water flow to get sustained drag reduction. It has been shown there that the shape and depth of the air-water interface affect the wall drag.

Investigating the flow physics of air curtains using experimental and numerical methods

The flow due to air curtains presents a fascinating interplay of jet inertia and buoyancy forces. The relative strength of the transverse stack effect determines jet establishment and evolution. In FE2B, we combine experiments and simulations to study these flows, relevant to environmental sciences. Conductivity and density measurements estimate bulk fluid exchange, while particle image velocimetry captures flow evolution. Numerical modeling using RANS and LES provides three-dimensional velocity and density fields, complementing experimental data. Experiments offer time-resolved insights into transient flow patterns, enabling critical analysis when combined with simulations. This integrated approach reveals the complex physics governing air curtain flows.

Spatiotemporal CO₂ monitoring as a proxy to understand and visualize building airflows at full-scale

Ensuring adequate ventilation and maintaining a well-mixed indoor environment is essential for improving Indoor Air Quality (IAQ). However, increasing ventilation can also facilitate the transport of outdoor pollutants into indoor spaces, a significant concern in highly polluted urban areas. This research addresses this dichotomy by analyzing invisible airflow patterns within buildings, using spatiotemporal CO2 data as a proxy at the full-building scale, and integrating reduced-order modeling (ROM). Furthermore, the study investigates the interplay between the spatiotemporal dispersion of CO2, PM2.5, temperature, and relative humidity.

Acoustic radiation of bubbles and vortices

The core looks at the principles governing the behavior and flow structure of sound waves as they travel through water, providing an understanding of the sea or ocean acoustic environment. Sound propagation adheres to the same fundamental principle in the air but has distinct differences in water's viscous and elastic nature. The molecular density provides faster wave traveling characteristics for water than air. The sound waves encounter various interfaces leading to reflection and refraction, making it crucial in sonar applications. These sound waves dissipate energy while traveling in water due to absorption and scattering. The higher frequencies are absorbed more readily, leading to effective communication and detection systems change. The sound traveling profile varies with depth, temperature, and salinity. This sound speed affects sound propagation and can create sound channels where waves travel long distances with minimal attenuation. Marine life, geological activity, human activities like drilling, sonar operation and ocean currents generate underwater acoustic noise.

Bio-fluid mechanics and cancer dynamics

For a long time, researchers all over the world have been trying hard to understand and fight against cancer, which is a very complicated disease. One big problem they're facing is figuring out how cancer cells can stay alive, move around in the body, and get into blood vessels despite the strong forces of blood flow. Recently, researchers have started using a mix of ideas from biology, physics, and engineering called "bio-fluid mechanics" to help them understand this problem better.

Cloud microphysics

The human relationship with rain is intricate because rain serves both as an inconvenience and a necessity. Therefore, curiosity about the process of rain formation shouldn’t be surprising. The urge to understand rain is so strong that scientists have persisted in their efforts, despite each new study revealing increasing complexity. Initial studies were conducted before a full understanding of the turbulent fluid environment, a defining characteristic of rain clouds, was achieved. Fortunately, the proliferation of advanced experiments has enabled researchers to delve more deeply into the added complexity that air turbulence brings to the rain formation puzzle. Even today, despite the rapid growth in computer processing speed, the wide range of scales involved in the precipitation process requires computing power that may not be available for decades. Equally challenging are experimental observations. Making precise measurements of the small-scale precipitation processes from a platform that must endure the harsh conditions of clouds is dangerous and expensive. However, precisely these types of challenges make this problem so engaging, and this enduring interest has persisted for decades. At present, the scientific community has a solid qualitative understanding of how precipitation forms. However, some parts of the process still lack the necessary understanding to make accurate quantitative predictions. Therefore, at the Fluid Mechanics Laboratory in the Department of Applied Mechanics at IIT Delhi, we are investigating the behavior of droplets in turbulent environments. These investigations are directly relevant to understanding the collision-coalescence process that takes place during the creation of warm rain.

Energy extraction via vortex-induced oscillation and vibrations

A novel approach rooted in harvesting energy from wind and current through vortex-induced motions has emerged recently. Our research endeavors align with this paradigm and entail the utilization of flat plates and cylindrical bluff bodies within a controlled wind tunnel environment. The objective is to capitalize on fluid-induced motions to harness energy effectively. In the specific context of flat plate autorotation, we systematically explore the effects of non-dimensional parameters to delineate distinct regimes encompassing oscillations, autorotation, and stationary states. Central to this investigation is the comprehensive characterization of energy extraction mechanisms facilitated by vortex-induced angular motion. The research methodology encompasses meticulous flow visualization and diagnostic techniques to elucidate intricate fluid-structure interactions, vortex-shedding phenomena, and the intricate mechanisms underlying energy transfer.

Members

Principal Investigator

Narsing Kumar Jha

Assistant Professor

Department of Applied Mechanics, IIT Delhi

PhD Students

Tanmay Agrawal

2021-Present

(Co-advised by V.K. Chalamalla)
Research Topic:
Experimental and Numerical Investigation of the Mixing Dynamics in Air Curtains

Manoj Kumar Gupta

2021-Present

Research Topic:
Experimental Study of Interaction of Vortex Rings with Droplets

Sitaram Sahu

2022-Present

(Co-advised by Sachin Kumar B)
Research Topic:
Development of Bio-Fluidic Model to Study the Role of Hemodynamic Forces on Cancer Metastasis

Suraj Narayan Dhar

2022-Present

Research Topic:
Underwater Acoustic Signatures of Interaction of Bubbles and Vortices

Abhijeet Singh

2022-Present

(Co-advised by Deepanshu Shirole)
Research Topic:
Experimental Investigations on Dry Granular Mass Flow using Flume based Physical Model

Bhramar Sanjay Pustode

2023-Present

(Co-advised by Amitabh Bhattacharya)
Research Topic:
Energy Extraction via vortex Induced Vibration

Vamsi Krishna Bankapalli

2023-Present

(Co-advised by Jay Dhariwal)
Research Topic: IAQ Management in Polluted Cities: The Role and Consequences of Building Ventilation

Kumar Saurabh

2023-Present

(Co-advised by V.K. Chalamalla)
Research Topic:
Drag Reduction Strategies for Green Shipping

MS(Research) Students

Vinay Likhar

2021-Present

Research Topic:
Trasition and Turbulence in Viscoelastic Channel Flows

Deeptanu Das

2022-Present

(Co-advised by V.K. Chalamalla)
Research Topic:
Numerical Simulation of Air Curtain Flows

Aditya Mishra

2023-Present

(Co-advised by Ajeet Kumar)
Research Topic:
Numerical Simulation and Physical Modelling of Vortex Induced Vibrations in Dam Gates

PG Students

Abhiram K

2022-Present

Research Topic:
Design and Development of Wake Homing Decoy

Bhanu Sahu

2022-Present

Research Topic:
Development and Construction of UUV (unmanned underwater vehicle)

Aman Kumar

2022-Present

Research Topic:
Design and Optimisation of Shower Head

Sujeet Kumar

2022-Present

Research Topic:
Elastic Instability for High Reynolds Number Flow

Priyam

2022-Present

Research Topic:
Energy Extraction from Angular Vortex Induced Vibrations

Dinesh Kumar

2022-Present

Research Topic:
Design and Fabrication of a Underwater Vehicle

Project Associates

Ritwik Das

2022-Present

Research Topic:
Search for Universal Mechanisms in Passive Drag Reduction in Turbulent Flows

B Tech Students

Preeti Choudhary

July 2023-Present

Shrijit Shaswat

July 2023-Present

Kanishka

July 2023-Present

Akula Jayanth

July 2023-Present

Alumni

Hari Prasad Bind

Graduated '22

(Interaction of Vortex Ring with Droplets)
Currently at IOCL

Adarsh Saini

Graduated '22

(Origin of Hydraulic Jump in a 2D Channel Flow)
Currently at IIT Roorkee

Amit Kumar

Graduated '22

(Design and Fabrication of Energy Harvestor Based on Vortex Induced Vibration)
Currently at HCL

Bikrant Rawat

Graduated '22

(Design and Optimization of Shower Head)
Currently at ISRO

Shubham Toke

Graduated '23

(Turbulent Flow in Microfluidics)
Currently at TVS Motor

Avinash Bhamu

Graduated '23

(Design and Fabrication of a Remotely Operated Underwater Vehicle)
Currently at Oceaneering

Riya Chaudhary

Graduated '23

(Energy Extraction from Vortex Induced Vibrations)
Currently at Bajaj Auto

FE²B Facilities

Experimental Facilities

Particle image velocimetry (PIV) measurements in air curtain flows

Acoustic measurement of compressed air bubble from a sintered nozzle using Hydrophone SONAR NEPTUNE

Flow visualization using time resolved µPIV in a 2D microchannel to study biofluid dynamics and flow instabilities

Study of circular hydraulic jump (CHJ)

Remotely operated underwater vehicle

Multiphase turbulent flow facility to study cloud microphysics

Publications

Google Scholar

Journals

Interaction of a vortex ring with a single bubble: Bubble and vorticity dynamics.
Narsing K. Jha, R. N. Govardhan, Journal of Fluid Mechanics 773, pp 460-497 (2015). PDF, Journal

Controlling air solubility to maintain “Cassie” state for sustained drag reduction.
D. Dilip, Narsing K. Jha, Raghuraman N. Govardhan, M.S. Bobji, Colloids and Surfaces A: Physicochemical and Engineering Aspects 459, pp 217-224 (2014). PDF, Journal

On the origin of the circular hydraulic jump in a thin liquid film.
Rajesh K. Bhagat, Narsing K. Jha, P. F. Linden, D. Ian Wilson, Journal of Fluid Mechanics 851, R5, pp 1-11 (2018). PDF, Journal

Effect of bubble distribution on wall drag in turbulent channel flow.
Narsing K. Jha, A. Bhatt, R. N. Govardhan, Experiments in Fluids 60(8), 127 (2019). PDF, Journal

Effect of human passage on air curtain effectiveness in the doorways of a building.
Narsing K. Jha, Lilian Darracq, Daria Frank, Paul F Linden, Journal of Fluid Mechanics (2019). PDF

Elastically driven Kelvin-Helmholtz-like instability in planar channel flow.
Narsing K. Jha, Victor Steinberg, PNAS 118,(34); e2105211118 (2021).

Implications of the spatiotemporal distribution of CO2 on indoor air quality: A field study with reduced-order modeling.
Vamsi Bankapalli, Narsing K Jha, Jay Dhariwal, Saran Raj K, Seshan Srirangarajan, Building and Environment 269, 112451 (2025) Journal

Injectable Hydrogels for Liver: Potential for Clinical Translation.
Ashwini Vasudevan, Doyel Ghosal, Sita Ram Sahu, Narsing K Jha, Pooja Vijayaraghavan, Sachin Kumar, Savneet Kaur, Chemistry: An Asian journal (2024) Journal

Performance and flow dynamics of heavy air curtains using experiments and numerical simulations.
Agrawal, T., Agarwal, S., Chalamalla, V.K, & Jha, N.K. Environmental Fluid Mechanics (2023) Journal

Universal coherent structures of elastic turbulence in straight channel with viscoelastic fluid flow.
Narsing K. Jha, Victor Steinberg, Science Advances; arXiv preprint arXiv:2009.12258 (2020).

Contaminant transport by human passage through an air curtain separating two sections of a corridor: Part I–Uniform ambient temperature.
Narsing K Jha, D Frank, PF Linden, Energy and Buildings 236, 110818 (2021) Journal

Contaminant transport by human passage through an air curtain separating two sections of a corridor: Part II–Two zones at different temperatures.
Narsing K Jha, D Frank, L Darracq, PF Linden, Energy and Buildings 236, 110728 (2021) Journal

Air curtains: validation of results from small-scale laboratory waterbath experiments by real-scale measurements in climate chambers and numerical simulations.
D Frank, Narsing K Jha, FGH Koene, REJ Kemp, A Twerda, PF Linden, Energy and Buildings 277, 112538 (2022) Journal

Numerical investigation of air curtain flows in the doorway of a building using RANS and LES.
Tanmay Agrawal, Narsing Kumar Jha, Vamsi Krishna Chalamalla arXiv preprint arXiv:2305.06697 (2023) Journal

Improvement in sealing effectiveness of air curtains using positive buoyancy.
Tanmay Agrawal, Narsing K Jha, Vamsi K Chalamalla Computers & Fluids 263, 105948 (2023) Journal

Elastic instability, flow relaminarization and suppression of vortices behind a cylinder for viscoelastic versus Newtonian fluid flow.
Vijay Kumar, Dong Yang, Atul Varshney, Narsing K. Jha, and Victor Steinberg, Physical review letters; Under review (2020).

Interaction of vortical structures with a single bubble in fully developed turbulent channel flow.
Narsing K. Jha, R. N. Govardhan, International Journal of Multiphase Flow; Under Review (2019).

Comparison of water bath air curtain measurements with the real-scale air curtain installations.
Narsing K. Jha, Daria Frank, Thomas van-Cann, Frans Cohn, Paul F Linden, Energy and Buildings; Under Preparation (2020).

Elastic instability and drag modification for an array of circular cylinders in viscoelastic flow.
Narsing K. Jha, Victor Steinberg, Physical review fluids; Under preparation (2020).

PhD Thesis (2015). PDF

Conference proceedings (peer-reviewed and published):

Energy Extraction from Fluid Flow via Autorotation of Flat Plate.
Bhramar Pustode, Amitabh Bhattacharya, Narsing Kumar Jha, Proceedings of the 11th International and 51st National Conference on Fluid Mechanics and Fluid Power (FMFP 2024), Aligarh Muslim University (AMU), Aligarh, India. (2024), (accepted).

On the origin of the circular hydraulic jump: a differential analysis.
P. F. Linden, R. K. Bhagat, N. K. Jha and D. I. Wilson, 21st Australasian Fluid Mechanics Conference; Adelaide, Australia (2018), PDF.

Effect of human walking on air curtain sealing in the doorway of an airtight building..
Narsing K. Jha, Lilian Darracq, Daria Frank, Paul F Linden, Air Infiltration and Ventilation Center (AIVC), Nottingham, UK (2017), PDF.

Conference abstracts:

Full-scale spatiotemporal CO2 measurements as a proxy for understanding the airborne dispersion of infectious microbes in indoor environments.
Vamsi Bankapalli, Narsing K. Jha, Jay Dhariwal, Saran Raj K, Seshan Srirangarajan, Accepted for presentation in Healthy Buildings 2025 Asia.

A reduced-order model to visualize transient passive scalar concentration distribution in indoor spaces.
Vamsi Bankapalli, Narsing K. Jha, Jay Dhariwal, Seshan Srirangarajan, Accepted for presentation in Healthy Buildings 2025 Asia.

Velocity statistics of air curtain flows using LES and PIV.
Tanmay Agrawal, Narsing K. Jha, Vamsi K. Chalamalla Presented in the 1st European Fluid Dynamics Conference, EFDC1 held at RWTH University, Aachen, Germany in September 2024. (2024).

Towards understanding air curtain flows using RANS based numerical simulations.
Tanmay Agrawal, Narsing K. Jha, Vamsi K. Chalamalla Proceedings of the ISHMT-ASTFE Heat and Mass Transfer Conference, IIT Madras, Chennai, Tamil Nadu, India (2021).

Effect of liquid surface tension on circular and linear hydraulic jumps; theory and experiments.
Rajesh Kumar Bhagat, Narsing K. Jha, Paul Linden, D I Wilson, APS Division of Fluid Dynamics Annual Meeting, Denver, Colorado (2017).

On the origin of hydraulic jump.
Rajesh Kumar Bhagat, Narsing K. Jha, Paul Linden, D I Wilson, UK Fluids 2018, University of Manchester, UK (2017).

A single bubble in a turbulent channel flow: Towards understanding drag reduction.
R. N. Govardhan, Narsing K. Jha, APS Division of Fluid Dynamics Annual Meeting, Portland, OR (2016).

Vorticity dynamics in the interaction of a single bubble with a vortex ring.
Narsing K. Jha, R. N. Govardhan, Journal of Fluid Mechanics APS Division of Fluid Dynamics Annual Meeting, Boston, MA (2015).

Interaction of a vortex ring and a bubble.
Narsing K. Jha, R. N. Govardhan, Journal of Fluid Mechanics APS Division of Fluid Dynamics Annual Meeting, San Francisco, CA (2014).

Vorticity and bubble dynamics of a vortex ring interacting with a bubble.
Narsing K. Jha, R. N. Govardhan, IUTAM Symposium on Multiphase flows with phase change: challenges and opportunities, IIT Hyderabad, India (2014).

Teaching

• Engineering Mechanics, APL100
• Mechanics of Solids and Fluids, APL105
• Mechanics of Fluids, APL107
• Engineering Thermodynamics, APL206
• Experimental Techniques in Fluids and Solids, APL390
• Solid & Fluids Lab, AMP262
• Applied Fluid Mechanics, AML713

Funding

Projects/Consultancies

May contact for consultancies related to flow measurement/device design, industrial flows, ships, non-Newtonian flows, micro fluidics, environmental flow, energy harvesting from flow etc.

Gallery

Outreach

• Visit of class 12 students from Government School



• Lecture delivery on the topic "Role of large data in studying turbulence" on 27^th July 2023 in an online five days Faculty Development program titled "Exploring Data Science: Foundations to Advanced Analytics" organised by Amity School of Engineering and Technology, Amity University Patna ,from 24^th - 28^th July, 2023




• Talk on the topic "Environmental fluid dynamics" on 12^th October 2021 in Faculty Development program on "Cutting-edge Multidisciplinary Research in the Field of Fluids" sponsored by AICTE Training And Learning (ATAL) Academy and organised by Department of Mechanical Engineering, NIT Rourkela, from 11^th - 15^th October, 2021

Collaborators

Raghuraman N. Govardhan

Professor, Department of Mechanical Engineering, Indian Institute of Science Bangalore

Paul F. Linden

G.I. Taylor Professor Emeritus of Fluid Mechanics, DAMTP, University of Cambridge, UK

Victor Steinberg

Emeritus Professor, Department of Physics of Complex Systems, Weizmann Institute of Science, Israel

Nishkarsh Gupta

MBBS, MD, DNB, PGCCHM, MNAMS, Professor, All India Institute of Medical Sciences, New Delhi

Navneet Kumar

Assistant Professor, Department of Mechanical Engineering, Indian Institute of Technology Jammu

Jay Dhariwal

Assistant Professor, Department of Design, Indian Institute of Technology Delhi

Seshan Srirangarajan

Assistant Professor, Department of Electrical Engineering, Indian Institute of Technology Delhi

Rama Krishna K

Assistant Professor, Department of Mechanical Engineering, Indian Institute of Technology Delhi

Sachin Kumar B

Assistant Professor, Centre for Biomedical Engineering, Indian Institute of Technology Delhi

Sanjeev Sanghi

Professor, Department of Applied Mechanics, Indian Institute of Technology Delhi

Ajeet Kumar

Professor, Department of Applied Mechanics, Indian Institute of Technology Delhi

Amitabh Bhattacharya

Professor, Department of Applied Mechanics, Indian Institute of Technology Delhi

Vamsi K. Chalamalla

Assistant Professor, Department of Applied Mechanics, Indian Institute of Technology Delhi

Murali R. Cholemari

Associate Professor, Department of Applied Mechanics, Indian Institute of Technology Delhi

Photos

Opportunities

I have openings for post-doc and JRF/project scientist. I strongly encourage dedicated students to contact me for their Masters or PhD study. My lab (Fluids lab for Environment, Engineering, and Biology: FE²B) focuses on Understanding Turbulence For Societal And Industrial Need: Two phase, Stratified And Elastic flows. We are basically a group of experimental enthusiasts interested in solving fluid dynamics problems. Interested students are encouraged to contact me personally at narsingjha@am.iitd.ac.in attaching resume and SOP.