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Building LecturePulse and SAM: making lectures more responsive
Published:
Whether I’m teaching Thermodynamics or Computational Fluid Dynamics, I see the same pattern. Students who miss one step, such as setting up an energy balance or following a stability argument, rarely say so in the moment. By the time it shows up on an exam, several weeks of material have piled on top of it. This summer I built two tools to close that gap. Both are freely available and live on the Teaching page.
Neil Wandmacher Teaching Award
Published:
I’m grateful to receive the Neil Wandmacher Teaching Award for Early Career Faculty from the College of Engineering and Applied Science.
Cover article in Langmuir: switching a meniscus with temperature
Published:
Our paper An Experimental Study of Interfacial Dynamics Control Using Temperature-Sensitive Surfactants is out in Langmuir, and it was selected as a cover article for the May 26, 2026 issue (Vol. 42, No. 20)!
A season of student fellowships
Published:
UCLID students have collected a remarkable set of competitive awards over the past several months:
New paper: identifying condensation flow regimes by sound
Published:
Our paper Slug Flow Condensation Identification with Acoustic Signatures is now published in the International Journal of Heat and Mass Transfer.
ASTFE 2026: thin film stability talks and an Early Career Researcher Award
Published:
At the 11th Thermal and Fluids Engineering Conference, UCLID presented two talks on the dynamics of evaporating thin films:
Dr. Unmeelan Chakrabarti!
Published:
Congratulations to Unmeelan Chakrabarti on successfully defending his PhD dissertation, “A multiscale investigation of simplifying assumptions made during liquid-vapor phase change modeling.”
ASME IMECE 2025: three talks, a travel award, and a Rising Star recognition
Published:
UCLID traveled to ASME IMECE 2025 with three talks, all on our thin-film and multiscale phase change work:
Two new papers: evaporation without tuning coefficients, and switchable flow in porous media
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This fall brought two new publications from UCLID students.
New paper: are evaporation and condensation coefficients really equal?
Published:
Unmeelan’s second paper analyzing International Space Station experiments is now out in Nanoscale and Microscale Thermophysical Engineering: Investigating the Inequality of Phase Change Coefficients Using ISS Experimental Data.
Archived Updates
Published:
| Date | Event |
|---|---|
| 08/20/2025 | Unmeelan’s second paper on analysis of ISS experiments is now available! |
| 05/17/2025 | Prof. Bellur gave an invited talk at Oregon State University, Corvallis, OR (host: Prof. Andy Dong). |
| 05/13/2025 | We received the 2025 Gold Star Lab Award from the College of Engineering and Applied Science. |
| 05/07/2025 | Congratulations to Saaras for being selected to receive the 2025 Armstrong Fellowship for Discovery! |
| 05/01/2025 | Prof. Bellur gave an invited talk at Hokkaido University, Japan (host: Prof. Yutaka Tabe). |
| 03/12/2025 | Amirhosein led a team that won 1st place in the ASTFE Green Energy CFD Competition. |
| 03/11/2025 | Amirhosein and Ayaaz presented their work at the ASTFE conference. |
| 02/17/2025 | Prof. Bellur gave an invited talk at Ericsson, Sweden. |
| 02/11/2025 | Prof. Bellur gave an invited talk at Miami University, Oxford, OH (host: Prof. Andrew Sommers) |
| 12/04/2024 | Unmeelan successfully defended his PhD proposal and advanced to PhD candidacy! |
| 11/19/2024 | Unmeelan presented a talk at ASME IMECE and won the Outstanding Student Presentation Award! |
| 11/11/2024 | Prof. Bellur gave an invited seminar talk at Southern Methodist University (host: Prof. Ali Beskok). |
| 10/30/2024 | Prof. Bellur gave an invited seminar talk at Embry-Riddle Aeronautical University (host: Prof. Sandra Boetcher). |
| 08/28/2024 | Unmeelan and Ayaaz presented their work at the NASA Thermal Fluids and Analysis Workshop (TFAWS). |
| 05/30/2024 | Congratulations to Sandeepan on a successful MS thesis defense! |
| 05/29/2024 | Ayaaz successfully defended his MS thesis and will continue at UCLID as a PhD student. |
| 05/10/2024 | Tejas successfully defended his MS thesis. Congratulations! |
| 05/06/2024 | Congratulations to Manjeera on a well-executed PhD dissertation defense! |
| 04/21/2024 | Prof. Bellur presents a talk on cryo/neutron experiments at ASTFE 2024 |
Spring 2025 seminar tour: Miami, Sweden, Japan, and Oregon
Published:
This spring I had the chance to share UCLID’s work with a wide range of audiences in academia and industry:
UCLID receives the 2025 Gold Star Lab Award
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We are honored to receive the 2025 Gold Star Lab Award from UC’s College of Engineering and Applied Science.
ASTFE 2025: two talks and a first-place CFD competition win
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UCLID had a strong showing at the 10th Thermal and Fluids Engineering Conference (ASTFE).
Outstanding Student Presentation Award at ASME IMECE 2024
Published:
Congratulations to Unmeelan Chakrabarti, who won an Outstanding Student Presentation Award at ASME IMECE 2024 for his talk “Investigating the sensitivity of inequal evaporation and condensation coefficients during liquid vapor phase change using data from Constrained Vapor Bubble (CVB) experiments conducted in the International Space Station (ISS).”
APS DFD 2023
Published:
The 2023 Division of Fluid Dynamics Annual Meeting of the American Physical Society, held in Washington, DC, was a melting pot of innovative ideas and groundbreaking research. Our lab was thrilled to be a part of the event, where our student, Ayaaz Yasin, presented a talk on “A Numerical Study of Coefficient-free Kinetic Evaporation Modeling in Liquid Hydrogen” during Mutliphase Flows: Computational Methods session.
Three academic generations in one publication
Published:
We are happy to present our latest publication on analysis of the Constrained Vapor Bubble (CVB) experiment on the International Space Station (ISS).
New Website!
Published:
While we have had a formal UC website, it was time to revive my defunct personal website and transform it into a group website. Historically, I have refrained from “posting” anything on a public form. I’ve realized I need to overcome this and what better way than to put my students front-and-center and empower them to post updates while learning to use git effectively and maintain the site. As with a lot of things we do at UCLID, this is an experiment that will evolve with time and group interests but I hope that this becomes a productive (and fun) exercise that keeps the website more active.
people
Amirhosein Sarchami
PhD Student, 2023 - present.
Porous Media, Two-Phase Flow, Thermal Management, Li-ion Battery, Optical Microscopy
Ayaaz Yasin
PhD Student, 2022 - present.
Computational Fluid Dynamics, Multiphase Flows, Phase Change Modeling, Molecular Dynamics
Denis Fulks
BS Alum, May 2024 - August 2024.
Sensor Design and Calibration, Control Systems, CAD Modeling, 3D Printing
Emmett Looman
BS Student, 2025 - present.
Fluid Mechanics, Signal and Image Processing, Optics
Ermiyas Lakew
MS Alum, 2021 - 2022.
MS Thesis, "Thin Film Evaporation Modeling of the Microlayer Region in a Dewetting Water Bubble", 2022. Currently R&D Test Engineer at FERNO.
Jon Scheckel
BS Alum, Fall 2025 - Spring 2026.
Undergraduate researcher, 2025–2026. 1819 Innovation Award winner.
Kishan Bellur
Principal Investigator, 2021 - current.
10+ years of experience in phase change heat transfer, capillary phenomena, cryogenics and scientific computing
Manjeera Vinnakota
PhD Alum, 2016 - 2024.
PhD Dissertation, "Design and Investigation of a Hydraulic Milli-Actuator for Minimally Invasive Medical Applications", 2024. Currently Project Manager at Ethicon (J&J MedTech).
Saaras Pakanati
BS Alum, 2024 - 2026.
Undergraduate researcher, 2024–2026, with 2 journal publications (1 first-author). Currently a PhD student at Rice University.
Sandeepan Dasgupta
MS Alum, 2021 - 2024.
MS Thesis, "Optical Transmission through Sessile Water Droplets Undergoing Solidification, and the Effect of Hydrophobicity", 2024. Currently at IIT Bombay.
Tahsin Enam
PhD Student, 2025 - present.
Multiphase flows, Fluid Mechanics, Heat & Mass Transfer
Tejas Mahajani
MS Alum, 2022 - 2024.
MS Thesis, "Experimental and Numerical Investigation of Isothermal Bubbling in Shear-thinning Liquids", 2024. Currently at Johnson Controls.
Trevon Collins
BS Alum, May 2026 - August 2026.
Summer 2026 REU student from Tennessee Tech. Currently co-authoring a paper.
Unmeelan Chakrabarti
PhD Alum, 2022 - 2026.
PhD Dissertation, "A multiscale investigation of simplifying assumptions made during liquid-vapor phase change modeling", 2026. Currently Senior Mechanical Development Engineer at Virginia Transformer Corp.
William Cullen
MS Alum, 2023 - 2025.
MS Thesis, "Contactless Cleaning using Leidenfrost Droplets", 2025.
publications
Neutron Radiography of Condensation and Evaporation of Hydrogen in a Cryogenic Condition
Journal of Heat Transfer, 2015.
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Visualization of the Evaporation and Condensation Phenomena in Cryogenic Propellants
Journal of Flow Visualization and Image Processing, 2016.
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Contact Angle Measurement of Liquid Hydrogen (LH2) in Stainless Steel and Aluminum Cells
Journal of Heat Transfer, 2016.
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A New Experiment for Investigating Evaporation and Condensation of Cryogenic Propellants
Cryogenics, 2016.
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Examining Liquid Hydrogen Wettability Using Neutron Imaging
Journal of Heat Transfer, 2016.
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Neutron Attenuation Analysis of Cryogenic Propellants
Journal of Heat Transfer, 2018.
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Determining Solid-Fluid Interface Temperature Distribution during Phase Change of Cryogenic Propellants Using Transient Thermal Modeling
Cryogenics, 2018.
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Rapidly Responsive Smart Adhesive-Coated Micropillars Utilizing Catechol–Boronate Complexation Chemistry
Soft Matter, 2019.
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Optical Properties and Swelling of Thin Film Perfluorinated Sulfonic-Acid Ionomer
ECS Transactions, 2019.
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Drifting Mass Accommodation Coefficients: In Situ Measurements from a Steady State Molecular Dynamics Setup
Nanoscale and Microscale Thermophysical Engineering, 2020.
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Multiscale Approach to Model Steady Meniscus Evaporation in a Wetting Fluid
Physical Review Fluids, 2020.
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Results from Neutron Imaging Phase Change Experiments with LH2 and LCH4
Cryogenics, 2022.
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Data from Cryo-Neutron Phase Change Experiments with LH2 and LCH4
Data in Brief, 2022.
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An Investigation of Phase Change Induced Marangoni-dominated Flow Patterns Using the Constrained Vapor Bubble Data from ISS Experiments
Frontiers in Space Technologies, 2023.
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Thin Film Evaporation Modeling of the Liquid Microlayer Region in a Dewetting Water Bubble
Fluids, 2023.
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Modeling Liquid-Vapor Phase Change Experiments: Cryogenic Hydrogen and Methane
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2023.
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Design and Modeling of a Miniature Hydraulic Motor for Powering a Cutting Tool for Minimally Invasive Procedures
Micromachines, 2023.
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Investigating the Efficiency of a Novel Combined Direct/Indirect Thermal Management System in Optimizing the Thermal Performance of a New Generation 46800-Type LIB Pack
Applied Thermal Engineering, 2023.
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Scaling a Hydraulic Motor for Minimally Invasive Medical Devices
Micromachines, 2024.
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Characterizing Optical Transmission Through Sessile Water Droplets Undergoing Solidification
Journal of Flow Visualization and Image Processing, 2025.
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Lessons Learned From Pandemic-Driven Remote Learning and Sustaining Best Practices in Turbomachinery Laboratory Experiences
Journal of Turbomachinery, 2025.
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Hydraulic Micromotor Powered Dissector for Minimally Invasive Therapy
Discover Mechanical Engineering, 2025.
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Investigating the Inequality of Phase Change Coefficients Using ISS Experimental Data
Nanoscale and Microscale Thermophysical Engineering, 2025.
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Computational Modeling of Evaporation without Tuning Coefficients
Applied Thermal Engineering, 2025.
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A Multiscale CFD Model of Evaporating Hydrogen Menisci: Incorporating Subgrid Thin-Film Dynamics and In Situ Accommodation Coefficients
Fuels, 2026.
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Slug Flow Condensation Identification with Acoustic Signatures
International Journal of Heat and Mass Transfer, 2026.
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An Experimental Study of Interfacial Dynamics Control Using Temperature-Sensitive Surfactants
Langmuir, 2026.
Cover article. Open access (CC-BY): read the paper here.
A Computational Model for Pore-Scale Flow Regime Tuning with Thermally Responsive Surfactants
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2026.
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research
Cryogenic Fuel Management
Measuring and modeling how liquid hydrogen and methane evaporate, condense, and wet surfaces. We use neutron imaging to see through metal containers at cryogenic temperatures, and we build predictive models that don’t need tuning coefficients.
ISS Experiments
Using data from the Constrained Vapor Bubble experiment on the International Space Station to test assumptions that phase change models routinely make. Without gravity, surface tension and Marangoni flow take over, and the interface physics is easier to see.
Molecular Dynamics
Simulating individual molecules crossing a liquid–vapor interface, so the parameters that continuum models usually guess can be calculated from first principles.
Porous Transport
Controlling how liquids move through porous materials by adjusting wettability. Thermally responsive surfactants make it possible to switch flow regimes at the pore scale with a change in temperature.
Thin Film Evaporation & Stability
Most of the heat transfer during evaporation happens in a liquid film only nanometers to micrometers thick, near the contact line. We model and measure how these films evaporate, oscillate, and destabilize.
Acoustic Diagnostics of Two-Phase Flow
Listening to boiling and condensation. We use acoustic signatures to identify two-phase flow regimes and to warn of critical heat flux without needing optical access.
Oil-Water Interfacial Dynamics
Switching the shape of an oil–water meniscus on demand. Using temperature-sensitive surfactants, we can reversibly flip a meniscus between concave and convex with a small temperature change. This work was featured on the cover of Langmuir.
talks
Neutron Bidography of Condensation and Evaporation of Hydrogen in a Cryogenic Condition
Published:
The presentation focused on the setup and preliminary images from a feasibility campaign. This was the first time neutron images of evaporating liquid hydrogen was presented. The presentation resulted in a journal article published in Journal of Heat Transfer
A new experiment for determining evaporation and condensation coefficients of cryogenic propellants
Published:
NASA Early Stage Innovation Workshop on Measuring Accommodation Coefficients.
Kinetic modeling and neutron imaging experiments of evaporation in cryogenic propellants
Published:
The graduate research colloquium is an opportunity to share student research with the university community and gain experience in presenting in a conference style setting.
A New Experiment for Determining Evaporation and Condensation Coefficients of Cryogenic Propellants
Published:
The presentation focused on the development of a new experimental method to determine accommodation coefficients. The ability to visualize liquid hydrogen was emphasized The presentation resulted in a journal article published in Cryogenics
Contact angle measurement of Hydrogen in a Cryogenic Condition
Published:
Contact angles of liquid hydrogen as measured by neutron image analysis were discussed.
Neutron Radiography of Condensation and Evaporation of Hydrogen in a Cryogenic Condition
Published:
Wettability of hydrogen is investigated through neutron image processing using a conical cell and results discussed. The presentation resulted in a journal article published in Journal of Heat Transfer
A new method to investigate evaporation and condensation of cryogenic propellants and determine accommodation coefficients
Published:
A poster presented to the chemistry community emphasizing the applicability of using neutron imaging to understand fundamental surface science.
Determining the evaporation and condensation coefficients of cryogenic propellants
Published:
The poster presentation won a 3rd place award in the graduate student category!
Determining solid-fluid interface temperature distribution during phase change of cryogenic propellants using transient thermal modeling
Published:
Kishan Bellur received a scholarship to travel/attend/present at this workshop. The presentation resulted in a journal article published in Cryogenics
Neutron attenuation analysis of cryogenic propellants
Published:
The presentation resulted in a journal article published in Journal of Heat Transfer
A novel method to determine accommodation coefficients of cryogenic propellants
Published:
The presentation focused on the ability to to combine experimental data with computational modeling to obtain the accommodation coefficients. Experimental data and progress on the modeling framework was presented.
Visualization of Evaporation/Condensation in Cryogenic Propellants
Published:
Kishan Bellur received the best oral presentation award!
A combined experimental and multi-scale modeling approach to determine phase change coefficients of cryogenic propellants
Published:
IMA workshop on Dynamic Contact Lines: Progress and OpportunitiesâÂÂ. Kishan Bellur received travel support to attend/present at this workshop.
Modeling of liquid-vapor phase change and associated processes
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Invited by Prof. Mark Weislogel
Using neutron imaging to investigate cryogenic phase change
Published:
Invited by Prof. Jaroslaw Drelich.
Determining the evaporation and condensation coefficients of cryogenic propellants
Published:
The poster highlighted neutron imaging as an ideal probe to visualize cryogenic propellant phase change. Importance and applications of the accommodation coefficient of cryogenic propellants were discussed.
Grant Writing as a Graduate Student: Practical Tips and Benefits
Published:
Invited by Prof. Jaroslaw Drelich. Panel discussion with Jessica Brassard and Allison Hein.
Mass Accommodation Coefficients of Cryogenic Propellants
Published:
The first estimates of the accommodation coefficient(s) for liquid hydrogen were presented. Kishan Bellur won the best poster award!
A combined experimental and multi-scale modeling technique to determine accommodation coefficients of cryogenic propellants
Published:
The cryo-neutron experiments were presented in detail and the modeling effort was introduced briefly. The supplementary GRC talk addressed the model and the accommodation coefficients.
A combined experimental and multi-scale modeling technique to determine accommodation coefficients of cryogenic propellants
Published:
The multi-scale modeling methodology and the accommodation coefficients for liquid hydrogen and methane were discussed in detail. The supplementary GRS talk addressed the cryo-neutron experiments.
Thermo-Mechanical Phase Change Stability of Liquid-Vapor Meniscus
Published:
The stability of thin liquid films was discussed from the context of liquid-vapor phase change. A new scaling analysis was presented.
Aerospace Engineering 101
Published:
This presentation to the local Houghton community included an outdoor model rocket launch demonstration.
Multiscale modeling of liquid-vapor phase change based on experimental data
Published:
The complete cryo-neutron story is presented in an integrated modular approach. The experiments, thermal transport analysis and multi-scale evaporation modeling are combined to generate the accommodation coefficients for both hydrogen and methane. The resulting values are independent of both container material and size and agree well with a fluid independent transition state theory prediction.
Neutron Imaging: a non-destructive diagnostic tool for cryogenic propellant investigations
Published:
Invited by Prof. K. T Vasudevan
Testing fundamental assumptions using Constained Vapor Bubble (CVB) data from ISS experiments
Published:
Liquid-vapor phase change: a cryo/neutron study
Published:
Invited talk for the Dept of Mechanical and Materials Enineering graduate seminar
Guess free evaporation modeling without adsorbed film constraints
Published:
A pdf of the poster is avilable here
Testing the equivalence of phase change coefficients based on the constrained vapor bubble (CVB) data from ISS experiments
Published:
This presentation highlights Marangoni flow along the interface resulting in a complex wavy flow pattern. Steps toward determining phase change coefficients are discussed.
Exploring the inequality of evaporation and condensation coefficients based on ISS experiments
Published:
Thin film evaporation modeling of the microlayer region in a dewetting water bubble
Published:
A custom thin-film evaporation model was developed to describe the microlayer region of a dewetting water bubble. The model incorporates high spatio-temporal resolution film thickness and temperature measurements and shows the mass flux non-uniformity in the microlayer region during the dewetting process.
Modeling of Liquid Microlayer Region in a Dewetting Water Bubble
Published:
We use our thin film modeling in conjunction with high resolution experimental data to show that the evaporation coefficient is not a constant but varies with time/thermophysical properties during the ebullition process.
Resolving discrepancy in accommodation coefficients by rethinking equilibrium assumptions in evaporation modeling
Published:
The cryo-neutron dataset was used in conjunction with our multiscale evaporation model to show that the interface is non-isothermal. Most studies in the past have assumed an isothermal interface based on equilibrium arguements leading to the discrepency in reported values. We showed that accounting for non-uniformity in temperature and pressure results in a predictable coefficient.
Results and lessons from cryogenic phase change experiments with LH2 and LCH4
Published:
Results and lessons from the cryo/neutron experiments were presented in detail in this 30 min lecture. The non-isothermal / non-equilibrium nature of the phase change process and its implication in reported coefficient values were discussed.
Exploring Two-Dimensional Flows in Evaporating Thin Films: A Step Towards a Dynamic Model
Published:
Controlling capillary flow in porous media
Published:
Multiscale Oscillations in Thin Liquid Films
Published:
teaching
Summer Youth Program - Rocketry and Space Science
Workshop, Michigan Technological University, 2018
Fluid Mechanics and Heat Transfer: Internal Flow
Undergraduate course, Michigan Technological University, 2019
In the spring semester of 2019, Dr. Bellur taught his first ever course as primary instructor: a 4 credit junior level undergraduate course in thermo-fluids. This unique course focused on fundamentals and applications of fluid mechanics and heat transfer to fluid flow in ducts and pipes (internal flow). Concepts from fluid mechanics and heat transfer were taught simultaneously in an integrated thermal-fluids approach.
Computational Fluid Dynamics
Undergraduate/Graduate course, University of Cincinnati, 2026
EGFD 5137/6037, taught every spring and rebuilt from scratch in 2022. Students write their own solvers, then complete an individually scoped, semester-long project run like a real conference cycle (abstract, presentation, paper). Several projects have gone on to conference and journal publications, and one grew into a full thesis.
Thermodynamics
Undergraduate course, University of Cincinnati, 2026
MECH 2010, taught every fall. A required second-year course redesigned around group problem-solving and open-ended design projects. It uses a gamified zyBooks platform with custom content Prof. Bellur helped build, live LecturePulse feedback, and a pilot of SAM, an AI study assistant grounded in the course’s own lectures.