Principal CFD Engineer

PhysicsX; New York (NY); Hybrid; USD 100,000 - 130,000; Full time

Benefits offered by this job

Equity options

5% contribution to 401(k)

Free team lunch 1× week

Private health insurance

Enhanced parental leave

20 days of annual leave

Personal development support

Gympass / Wellhub (subsidized)

Flexible Spending Account (FSA)

Job summary

PhysicsX is hiring a Principal Simulation Engineer in New York to lead complex multi-physics simulations and work closely with customers on engineering challenges. Candidates should have 5+ years of experience, strong expertise in fluid mechanics and tools like Star-CCM+, and the ability to mentor junior staff. The role involves global travel and combines technical leadership with customer interaction. PhysicsX offers rich benefits including stock options, a 401(k) contribution, and comprehensive health insurance.

Qualifications

• 5+ years of industry experience in a commercial environment.
• Proficient in setting up CFD simulations independently.
• Experience in parametric CAD modelling and coding is an advantage.

Responsibilities

• Lead the technical direction and delivery of simulation workstreams.
• Partner with customers to provide engineering solutions.
• Build complex multi-physics models and validate them with experimental data.
• Work at the intersection of CAE and Data Science.
• Mentor junior colleagues and promote a culture of collaboration.

Skills

Fluid mechanics

Heat transfer

Multiphase modelling

Star-CCM+

OpenFOAM

Fluent

Python

Java

Education

Masters or PhD

Tools

NX

CATIA

Job description

PhysicsX is a deep‑tech company with roots in numerical physics and Formula One, dedicated to accelerating hardware innovation at the speed of software. We are building an AI‑driven simulation software stack for engineering and manufacturing across advanced industries. By enabling high‑fidelity, multi‑physics simulation through AI inference across the entire engineering lifecycle, PhysicsX unlocks new levels of optimization and automation in design, manufacturing, and operations – empowering engineers to push the boundaries of possibility. Our customers include leading innovators in Aerospace & Defense, Materials, Energy, Semiconductors, and Automotive.

Who We’re Looking For

As a Principal Simulation Engineer (Delivery), you are a technical leader and problem solver who is passionate about creating practical, high‑impact solutions that enable customers to make better engineering decisions. You combine deep simulation expertise with strong leadership and customer ownership, and you excel at working directly with customers (often directly on‑site) to build CAE models that are integrated into AI‑tools that are both useful and used.

You bring deep expertise in fluid mechanics, heat transfer, and multiphase modelling, with a solid ability to apply fundamental knowledge to real‑world phenomena across a wide range of engineering applications. Highly proficient in at least one of Star‑CCM+, OpenFOAM, or Fluent and adept at automating these tools to create scalable optimisation workflows that drive impactful results. Experience in parametric CAD modelling (NX or CATIA) and coding in Python/Java, (or the ability to quickly learn programming languages), is an advantage.

With 5+ years of industry experience (post Masters or PhD) in a commercial, non‑research environment, you’re ready to hit the ground running. You’re confident setting up CFD simulations independently, interpreting complex results with depth, and making informed decisions based on solid engineering judgement.

Note: Due to the nature of our aerospace and defense work, this position is open to US citizens only.

This Role

In this role, you’ll work closely with our Data Scientists, Machine Learning Engineers, and customers to understand and define the engineering challenges we are solving.

You’ll play a crucial role in delivering high‑fidelity simulations by:

• Leading the technical direction and delivery of complex multi‑physics simulation workstreams, remaining hands‑on for the most challenging aspects while guiding teams through execution.
• Partnering with customers to address their most complex engineering challenges through advanced CAE & AI solutions; presenting results clearly, recommending actionable next steps, and balancing accuracy with efficiency under tight deadlines.
• Independently building and/or guiding others to develop complex multi‑physics models from geometry clean‑up and meshing, to simulating and post‑processing complex real‑world phenomena, integrating experimental data for model validation.
• Building robust parametric CAD models (NX or CATIA) coupled with simulation pipeline automation, for executing advanced design optimization and DoE studies.
• Working at the intersection of CAE and Data Science to generate high‑quality simulation datasets for training machine/deep learning models. Leveraging data sampling techniques to efficiently capture the design space, reduce computational cost, and enhance model accuracy.
• Accelerating high‑fidelity modelling by using Flux (our cloud platform) and on‑premise HPC resources, going beyond smart meshing and model setup to achieve real performance gains.
• Continuously improving engineering best practices, adapting CFD model setups and outputs to support the development of deep learning surrogates.
• Combining project leadership with a strong commitment to mentoring junior colleagues, contributing to a culture of collaboration, growth, and shared success.
• Traveling globally (North America, Europe, Asia, Oceania), on average 3‑4 weeks per quarter, to work side‑by‑side with customers in building solutions on‑site.

This role is based in New York, working 2‑3 days per week in our Manhattan office.

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.

Benefits

Equity options – share meaningfully in the company you’re helping to build.

5% contribution to 401(k) – build long‑term security with a strong retirement plan.

Free team lunch 1× week – good food, great company, and space to connect.

Private health insurance – comprehensive cover for you, offering total peace of mind.

Enhanced parental leave – 3 months full pay paternity and 6 months full pay maternity leave, to provide extra flexibility during the moments that matter most.

20 days of annual leave (+ public holidays) – because taking time to rest matters.

Personal development – dedicated support for learning, development, and leveling up over time.

Gympass / Wellhub (subsidized) – for you and up to 3 family members, supporting both physical and mental wellbeing.

Flexible Spending Account (FSA) – set aside pre‑tax dollars for eligible healthcare expenses.

EEO Statement

We value diversity and are committed to equal employment opportunity regardless of sex, race, religion, ethnicity, nationality, disability, age, sexual orientation or gender identity. We strongly encourage individuals from groups traditionally underrepresented in tech to apply.

We collect diversity and inclusion data solely for the purpose of monitoring the effectiveness of our equal opportunities policies and ensuring compliance with UK employment and equality legislation. This information is confidential, used only in aggregate form, and will not influence the outcome of your application.