Senior CFD Engineer - Multiphase

Who we’re looking for

What you'll do

• Develop multiphase flow models for gas-liquid, solid-liquid, VOF, Euler-Euler/Euler-Lagrange approaches) across a range of industrial and process engineering applications
• Model non-Newtonian and complex fluid rheology modelling, including high-viscosity, shear-thinning or particle-laden flow regimes
• Reactive and coupled-physics flow modelling: link CFD with reaction kinetics, heat transfer or domain-specific process models (e.g. biokinetic, combustion or electrochemical frameworks)
• Own meshing generation and strategy for complex industrial geometries, including rotating machinery, internal flow passages, spargers and free-surface interfaces
• Build robust parametric CAD models (NX, CATIA or equivalent) tightly coupled with simulation pipelines, enabling automated design optimisation and DoE studies
• Multi-physics model development end-to-end: geometry clean-up, meshing, solver setup, post-processing and experimental data integration for model validation
• Scale-up/scale-down methodology: translate small-scale experimental data to full-scale CFD models and iterating model fidelity against physical measurements
• HPC: job scheduling, MPI-based distributed computing, GPU acceleration and performance tuning for large-mesh transient simulations on cloud (Flux) and on-premise resources
• Surrogate modelling and ML-CFD coupling: build reduced-order or AI surrogate models from high-fidelity CFD data to support design space exploration and process optimisation
• Data pipeline literacy: structure and curate CFD output datasets for downstream AI/ML training, active learning and Pareto optimisation workflows; applying data sampling techniques (LHS, quasi-random, adaptive) to efficiently cover design space
• Experimental validation workflows: compare simulation predictions against physical test data, interpreting discrepancies and systematically improving model fidelity
• Customer-facing delivery: partner with clients to scope and address complex engineering challenges via CAE and AI solutions; communicating results clearly, recommending actionable next steps and balancing accuracy with efficiency under commercial deadlines
• Proficiency in CFD solvers across open-source OpenFOAM and commercial platforms comes as a plus (Star-CCM+, Fluent or equivalent), including custom solver and boundary condition development.

As the role evolves, there are exciting opportunities for growth as an Individual Contributor (IC) or a Team Lead (TL), especially if you’re driven to take ownership of more complex projects and lead the direction of future solutions.

Our delivery teams drive innovation to turn AI models into practical solutions - read our blog to learn more about how you’ll contribute to this exciting journey!

https://www.physicsx.ai/newsroom/how-delivery-makes-physical-ai-work-in-the-real-world

What we offer

Build what actually matters

Help shape an AI-native engineering company at a formative stage, tackling problems that genuinely matter for industry and society. This is work with real-world impact - and something you can be proud to stand behind.

Learn alongside exceptional people

Work with a high-caliber, collaborative team of engineers, scientists, and operators who care deeply about doing great work, and about helping each other get better. We come from diverse backgrounds, but we share a commitment to operating at the highest level and addressing some of the most complex challenges out there. If you’re ambitious, thoughtful, and driven by impact, you’ll feel at home.

Influence over hierarchy

We operate with a flat structure: good ideas win - wherever they come from. Questioning assumptions and challenging the status quo isn’t just welcomed, it’s expected.

Sustainable pace, long-term ambition

Building meaningful technology is a marathon, not a sprint. We believe in balancing focused, ambitious work with a life beyond it. Our hybrid model blends time together in our New York office with work-from-home days, giving you the flexibility to work sustainably while staying connected in person.