Principal Thermal Engineer – Stevenage

Principal Thermal Engineer
Location: Stevenage
Duration: 12 months, with potential extension
Rate: Up to £50 per hour (Umbrella)
Clearance: SC required to start
Working Pattern: Onsite role (minimum 3 days per week, but assume full-time onsite)

We’re looking for an experienced Principal Thermal Engineer to join a leading defence engineering team in Stevenage. You’ll be part of a well-established Mechanical Analysis Group, working on complex and varied projects that shape the next generation of advanced military systems.

The Role

You’ll take technical ownership of thermal analysis activities, supporting projects from early concept stages through to final performance evidence. This includes:

• Delivering packages of thermal analysis work with clear conclusions

• Using a mix of hand calculations and Finite Element methods (e.g. ANSYS)

• Producing thermal studies involving conduction, convection and radiation

• Supporting thermal analysis of electronic assemblies and embedded systems

• Using MATLAB/Simulink, CFD tools or Python/MATLAB scripting where required

• Presenting findings in reports and at design reviews

• Working closely with multi-disciplinary teams and project stakeholders

• Managing your workload and providing regular progress updates

This position is ideal for someone who combines technical depth with strong communication skills and enjoys collaborating across engineering disciplines.

What We’re Looking For

• Degree in a STEM discipline (or equivalent experience)

• Proven background in thermal analysis

• Experience with heat transfer modelling using analytical and FEA methods

• One or more of the following is desirable:

  • Thermal analysis of electronic systems

  • MATLAB/Simulink thermal modelling

  • CFD for thermal behaviour

  • Python/MATLAB scripting

• Ability to make quick, practical assessments to support design decisions

• Confident communicator able to collaborate with internal and external teams

• Experience from defence, aerospace or electronics sectors is beneficial

Why Join?

This is an excellent opportunity to take a key role in a major defence engineering environment, working alongside highly skilled colleagues and contributing to products used globally. The project work is varied, technically challenging and makes a measurable impact.