Senior Thermal Engineer

We’re partnering with a seed-stage deep-tech startup building AI-native thermal engineering software that’s used to design next-generation heat exchangers for high-power systems in data centers, defense, and heavy industry. The company sits at the intersection of computational physics, simulation, and AI-driven design automation, and is now hiring a Senior Thermal Engineer (PhD-level) to act as the critical human-in-the-loop for their design platform and own real-world thermal hardware development.

This is a highly specialised, hands-on role for a true thermal-fluids expert – not a generalist mechanical engineer – who can design, validate, and physically reason through complex heat transfer systems from first principles, and bridge the gap between AI-generated designs and manufacturable hardware.

This is a fully remote position with a strong preference for East Coast hours and you must have full right to work in the US with either citizenship or permanent residency at the time of application.

Key Responsibilities:

• Design heat exchangers end-to-end, from blank CAD geometry through to simulation-validated, manufacturable hardware targeting aggressive thermal and pressure-drop constraints.
• Act as the human-in-the-loop for an AI-driven thermal design platform, validating outputs using first-principles 1D models and high-fidelity CFD/CHT simulations.
• Run and interpret advanced thermal-fluid simulations using tools such as STAR-CCM+, Ansys Fluent, nTop, PhysicsX, and EES to guide real engineering decisions.
• Ensure all designs are manufacturable, accounting for additive manufacturing constraints including support strategy, distortion, and post-processing requirements.
• Design and execute validation experiments, closing the loop between simulation and physical testing to refine models and design rules.
• Develop reusable simulation frameworks, parametric tools, and design methodologies to improve team velocity and scale thermal design capability.

Key Qualifications:

• PhD in Mechanical Engineering, Thermal Engineering, or a closely related field with a strong focus on thermal-fluid sciences, plus ~5+ years of post-PhD industry experience.
• Deep expertise in heat exchanger design, with at least one example of designing a system from scratch through to validated hardware (ideally at 200kW+ scale).
• Strong background in data center cooling, HVAC, liquid cooling systems (e.g., CDUs, rack-level thermal architectures), or similar high-performance thermal domains.
• Experience designing for metal additive manufacturing (L-PBF/SLM), including awareness of distortion, support structures, and powder removal constraints.
• Advanced proficiency in CFD and conjugate heat transfer simulation (STAR-CCM+, Ansys Fluent, or equivalent), including full setup and execution of real engineering problems.
• Ability to build first-principles 1D thermal models in tools like EES, MATLAB, or Python.
• Familiarity with topology optimization or generative design tools (e.g., nTop, PhysicsX) applied to thermal systems.
• Strong ownership mindset with ability to operate independently, define assumptions, and drive problems from ambiguity to solution under tight timelines.