Senior Thermal Engineer

Job Description :
Your impact

Shape the future of defence technology. Join Leonardo.

Leonardo is seeking an experienced Senior Thermal Engineer to play a key role in the development and production of cutting‑edge Electronic Warfare (EW) systems—supporting both new innovations and proven legacy products. Based at our Luton site, this role offers the flexibility of hybrid working and the opportunity to make a tangible impact across a wide range of high‑tech defence projects.

You’ll work at the heart of multidisciplinary project teams, advising on thermal performance and ensuring our products meet demanding environmental and operational requirements. This role is ideal for someone with a strong analytical mindset, a flair for problem‑solving, and the ability to manage complex interdependencies across multiple programmes and business units.

• Conduct thermal analysis of mechanical designs to assess performance and safety using thermal analysis software, CFD techniques, and classical hand calculations.
• Provide expert guidance on cooling strategies and recommend thermal design improvements as required.
• Advise on materials and manufacturing techniques with an emphasis on thermal performance and mechanical integrity.
• Define thermal requirements and develop methods for verifying compliance across Leonardo products.
• Drive innovation in thermal design, introducing new technologies and methodologies.
• Support product development through all phases—from design and testing to final certification.
• Deliver thermal solutions that meet performance requirements on time and within budget.
• Contribute to technical documentation, including material for peer reviews and stage / gate approvals.
• Collaborate across sites and with suppliers and customers through occasional travel.

• Degree in Mechanical or Aeronautical Engineering with post‑graduate experience in Thermal engineering.
• Proven expertise in thermal analysis, with a track record of developing equipment for challenging and extreme operating environments.
• Proficiency in CFD tools, preferably Ansys Icepak and Ansys Fluent, alongside a solid foundation in classical hand calculation methods.
• A good understanding of environmental testing for design verification, with familiarity in Mil‑Std‑810 and RTCA DO‑160 standards considered a strong asset.
• Knowledge of Regulatory Standards including but not limited to :
  Def Stan 00‑970, Health and Safety HSE Regulations including Hazardous Waste Regulation. Compliance with Pressure Equipment Regulation, Pressure System Safety Regulation and Fluorinated Gas Regulations.
• Awareness of equipment safety compliance requirements, including the ability to support inspection processes and generate fault and failure reports.

This is not an exhaustive list, and we are keen to hear from you even if you might not have experience in all the above. The most important skill is a good attitude and willingness to learn.

This role is subject to pre‑employment screening in line with the UK Government’s Baseline Personnel Security Standard (BPSS). An additional range of Personnel Security Controls referred to as National Security Vetting (NSV) may apply, this could include meeting the eligibility requirements for The Security Check (SC) or Developed Vetting (DV). For more information and guidance please visit :

At Leonardo, our people are at the heart of everything we do. We offer a comprehensive, company‑funded benefits package that supports your wellbeing, career development, and work–life balance. Whether you’re looking to grow professionally, care for your health, or plan for the future, we’re here to help you thrive.

• Time to Recharge :
  Enjoy generous leave with the opportunity to accrue up to 12 additional flexi‑days each year.
• Secure your Future :
  Benefit from our award‑winning pension scheme with up to 15% employer contribution.
• Your Wellbeing Matters :
  Free access to mental health support, financial advice, and employee‑led networks championing inclusion and diversity (Enable, Pride, Equalise, Armed Forces, Carers, Wellbeing and Ethnicity).
• Rewarding Performance :
  All…