Nicolas Tricard

Ph.D. Candidate, Mechanical Engineering · Massachusetts Institute of Technology

I research at the intersection of physical AI, thermal fluids modeling, and inverse optics sensing. By combining data-driven methods with high-performance computing, I have been able to construct simulation and inference systems that recover what cannot be measured directly and run them at the scale real problems demand.

Former Google Research simulation researcher · ESSCI Research Fellow (2026–2027) · GE Vernova Fellow (2025–2026)

Nicolas Tricard
MIT  ·  Google Research  ·  Oak Ridge National Laboratory  ·  U.S. Naval Research Laboratory  ·  UConn
Solvers scaling to 1,500 GPUs and 250 TPU cores
Differentiable simulation, inference & optical diagnostics
Ph.D. expected 2027

Selected work

Three threads run through my research — physical AI, thermal-fluid modeling, and inverse optics sensing — held together by high-performance computing. Most projects sit in more than one.

Differentiable physics & inverse problems

Time series comparing CFD flame fields with tomographic reconstructions from 4.1 to 8.0 seconds

MIT · 2025–present

Differentiable rendering for hyperspectral flame tomography

A differentiable-rendering framework for gradient-based 3-D reconstruction of temperature and species fields from hyperspectral images, built on GPU-accelerated non-gray radiative transfer in CUDA, JAX, and Julia, with diffusion and attention priors for sparse-view reconstruction.

Thermal wave driving frontal polymerization during additive manufacturing of a polymer

MIT · 2023–present

PDE-constrained inverse modeling of energetic materials

PDE-constrained sensitivity methods that infer material properties and chemical kinetics from thermal imaging, thermocouple, and spectrometer measurements of propagating reaction fronts. Differentiable solvers with adjoint sensitivities make the estimation scalable, and Bayesian inference over reaction-diffusion models keeps results physically consistent and uncertainty-aware.

Machine learning for physical systems

Velocity field reconstructions from sparse sensors compared across generative and neural-operator baselines

MIT · 2025–present

Digital twins from sparse sensor data

A global–local attention framework that fuses a learned global latent state with local sensor observations to reconstruct and forecast physical fields — including components no sensor observes — with quantified uncertainty with generative flow matching, trained on reacting-flow LES generated in OpenFOAM with detailed chemistry.

Waveform determination feeding a spectrum-matching inference loop of forward operator, discrepancy, gradient, and parameter update

MIT · 2026–present

Reinforcement learning design of experiments

Reinforcement learning combined with greedy active learning to decide what measurement to take next, generating custom wavelength-modulation spectroscopy waveforms at roughly 1 ms latency and accelerating information gain 20×–100× over state-of-the-art methods.

High-performance & distributed simulation

Multi-GPU ray-tracing system for participating-media radiation

Oak Ridge National Laboratory / UConn · 2020–2024

CUDA Monte Carlo ray tracing for emitting media

Led development of a CUDA 3-D forward ray-tracing solver with a line-by-line spectral database, coupled to OpenFOAM. BVH-based parallelization gave a >400× speedup and scaled to 1,500 GPUs on a top-3 supercomputer; later work with Kokkos and MPI addressed the communication bottlenecks.

Distributed Lagrangian particle simulation across TPU cores

Google Research · 2024

Lagrangian particle tracking on TPUs

A scalable multi-TPU Lagrangian particle-tracking solver for differentiable wildfire CFD in Swirl-LM, tested to 250 TPU cores. Optimizing SPMD execution meant reading TensorFlow and XLA HLO IR directly — which also surfaced a compiler bug I reported.

Core capabilities

Methods and software architecture are inseparable in my work: a model has to be both scientifically useful and practical at accelerator scale.

Differentiable & inverse simulation

Differentiable PDE, radiative-transfer, spectroscopy, and rendering models with adjoint sensitivities for gradient-based inference, instrument calibration, and system identification.

JAX · Julia · CUDA · adjoints · Monte Carlo ray tracing · line-by-line spectra

Machine learning for physical systems

Attention and diffusion models, generative priors, and reinforcement learning for reconstruction, forecasting, and experiment design under sparse observation.

PyTorch · JAX · Bayesian UQ · neural operators · active learning

High-performance & parallel computing

Scientific software from custom GPU kernels to multi-node communication design, distributed training, and compiler-level performance investigation.

C++ · MPI · OpenMP · Kokkos · XLA / HLO · Slurm · PBS

Thermal-fluid & reacting flow

High-fidelity modeling of fluid flow, combustion, radiative transfer, heat transfer, and multiphase transport, plus the reduced-order models that make them tractable.

OpenFOAM · Cantera · LAMMPS · finite volume · DG

Selected publications & talks

A focused selection spanning differentiable inference, optical diagnostics and tomography, scientific machine learning, and accelerated thermal-fluid modeling.

Invited talk · 2026

Multi-GPU Radiative Transport in Participating Media with Kokkos

Tricard, N. & Deng, S. High Performance Software Foundation Convention, Kokkos user group meeting, Chicago, IL, March 19. Watch the talk ↗

In press · 2026

Uncertainty-Aware Differentiable Spectroscopy for Multi-line Temperature and Multi-Species Tomography in an Ammonia/Methane-Fueled McKenna Burner

Tricard, N., Shanbhogue, S., Cherry, M., Chen, Z., Guerra-Garcia, C., Ghoniem, A., & Deng, S. Proceedings of the Combustion Institute.

Preprint · 2026

3-D representations for hyperspectral flame tomography

Tricard, N., Chen, Z., & Deng, S. arXiv:2603.27832. arXiv ↗

Preprint · 2026

GLU: Global-local-uncertainty fusion for scalable spatiotemporal reconstruction and forecasting

Wang, L., Chen, J., Tricard, N., Chen, Z., & Deng, S. arXiv:2603.26023. arXiv ↗

Journal article · 2026

Inlet Conditions and Fuel Effects on Structures in a Backward-Facing Step Combustor

Tricard, N. & Bojko, B. Journal of Propulsion and Power 42(2), 318–332. DOI ↗

Journal article · 2025

Hybrid physics-machine learning model for multispecies and temperature inference from FTIR spectra

Chen, Z., Tricard, N., & Deng, S. Proceedings of the Combustion Institute 41, 105811. DOI ↗

Journal article · 2025

Progress in computational methods and mechanistic insights on the growth of carbon nanotubes

Wang, L., Tricard, N., Chen, Z., & Deng, S. Nanoscale 17, 11812–11863. DOI ↗

Journal article · 2024

Optimal parameters of Monte Carlo ray tracing solver with line-by-line spectral database for radiation modeling in fire

Tricard, N., Fraga, G., & Zhao, X. Proceedings of the Combustion Institute 40(1), 105293. DOI ↗

Experience

Research roles spanning mathematical formulation, scientific software, performance engineering, and experimental validation.

2023–2027

MIT · Ph.D. Researcher in Differentiable Physics and Scientific ML

Differentiable simulation, PDE-constrained inverse modeling, and uncertainty-aware learned models for reacting, radiative, and thermal-fluid systems, validated against optical and thermal diagnostics.

Sept–Dec 2024

Google Research · Simulation Researcher

Built distributed multi-TPU Lagrangian particle tracking for differentiable wildfire CFD within Swirl-LM.

2022–2024

U.S. Naval Research Laboratory · Researcher in GPU-Accelerated Reacting-Flow Simulation

Contributed boundary conditions and reduced-order models to a CUDA-accelerated discontinuous-Galerkin Navier–Stokes solver for compressible reacting flow.

2020–2024

Oak Ridge National Laboratory / UConn · Researcher in GPU Radiative Transport

Led development of multi-GPU Monte Carlo radiation solvers with line-by-line spectral databases, coupled with CFD for fire, gas-turbine, and high-enthalpy propulsion applications.

2020–2023

University of Connecticut · Researcher in Reduced-Order Reacting-Flow Models

Developed 1-D multiphase detonation models reaching a 10⁶× speedup over direct numerical simulation while preserving the key physical trends.

Education & awards

2023–2027

Massachusetts Institute of Technology

Ph.D., Mechanical Engineering and Computational Science (expected May 2027).

2017–2022

University of Connecticut

M.S., Mechanical Engineering (Research Assistant). B.S., Mechanical Engineering, minor in Computer Science (Merit Scholar).

2026–2027

ESSCI Research Fellows Program

Competitive award for collaborative work in flame tomography.

2025–2026

GE Vernova Fellowship

Merit-based full Ph.D. funding; eight awarded across MIT annually.

2025–2026

MathWorks Fellowship

Merit-based full-funding offer, MIT.

About

I am a Ph.D. candidate in Mechanical Engineering and Computational Science at MIT, finishing in 2027. My research sits between three fields that increasingly need each other: physical AI, thermal-fluid modeling, and inverse optics sensing.

In practice that means building the solver and the inference method together — CUDA and JAX radiative transfer, adjoint-based PDE-constrained estimation, attention and diffusion models for sparse reconstruction — and then making the whole thing run at the scale the problem actually demands, whether that is 1,500 GPUs on a leadership-class machine or 250 TPU cores at Google Research. Much of it is anchored by real measurements: hyperspectral images, laser spectra, thermocouples and thermal cameras.

The applications have been combustion, fire, propulsion, and materials processing, but the methods are general: recovering what you cannot measure directly from what you can.