Principal Thermal Engineer

Yolk Recruitment Ltd; Stevenage; On-site; GBP 100,000 - 125,000; Part time

Job summary

A leading defence engineering firm in Stevenage seeks a Principal Thermal Engineer to take technical ownership of thermal analysis activities. The role involves delivering thermal analysis work, producing studies, and collaborating with multi-disciplinary teams. Ideal candidates should have a degree in a STEM field and a proven background in thermal analysis, along with experience in heat transfer modelling. This position offers the chance to work on complex projects with a significant impact in defense engineering.

Qualifications

• Proven background in thermal analysis required.
• Experience with heat transfer modelling using analytical and FEA methods.
• Confident communicator able to collaborate with internal and external teams.

Responsibilities

• Take technical ownership of thermal analysis activities.
• Deliver packages of thermal analysis work with clear conclusions.
• Produce thermal studies involving conduction, convection, and radiation.

Skills

Thermal analysis

Heat transfer modelling

MATLAB/Simulink

CFD tools

Python/MATLAB scripting

Communication

Education

Degree in STEM discipline or equivalent experience

Tools

ANSYS

Job description

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.