Thermal Design Engineer

The RLE INTERNATIONAL Group is one of the world's leading providers in the fields of vehicle development, technology and consulting. On the basis of more than 40 years of development & consulting, we provide innovative and effective solutions for our UK customers in the area of Automotive Engineering. RLE INTERNATIONAL is represented at locations close to its customers in Europe, Asia and USA.

Job Title:

Thermal Design Engineer

Job Description:

We are looking for an innovative and detail-oriented Thermal Design Engineer to join our automotive engineering team. The successful candidate will be responsible for the concept, design, analysis, and optimization of thermal systems and components across vehicle platforms. This includes ensuring optimal performance, energy efficiency, and reliability of thermal systems for propulsion, cabin climate control, battery management, and electronic components.

Key Responsibilities

Design and develop thermal management systems and components for electric power systems from Concept to Validation to go into vehicles.

• Knowledge of modelling and simulation of thermal behaviour using 1D/3D tools (e.g., GT-SUITE, ANSYS, Flowmaster, CFD tools).
• Specify, Evaluate and optimize cooling and heating strategies for batteries, HVAC systems, and electronics.
• Perform thermal analysis to ensure compliance with performance, durability, safety, and regulatory

requirements. 1D &3D analysis for Flow, flow balance, pressure drop & heat rejection.

• Collaborate with cross-functional teams including Electrical, HVAC, Battery, and Vehicle Integration to align thermal solutions with vehicle architecture.
• Specify, Develop and review component specifications, system schematics, and validation plans.
• Support prototype builds and perform validation testing (thermal cycling, environmental, performance).
• Interface with suppliers to review designs, material selection, and manufacturing feasibility.
• Drive continuous improvement in system efficiency, weight, cost, and packaging.
• Strong understanding of thermodynamics, heat transfer, and fluid dynamics.

Skills required:

• Proficiency in thermal simulation tools (e.g., GT-SUITE, ANSYS, MATLAB/Simulink, CFD software).
• Experience and delivery of automotive development tools and processes (DFMEA, DVP&R, APQP

requirements capture).

• Knowledge of automotive HVAC systems, powertrain cooling, and battery thermal management.
• Excellent experience in thermal system design or development.

Skills preferred:

Experience in EV or hybrid thermal system development.

Knowledge of refrigerant systems and regulations (R-134a, R-1234yf, CO₂).

Knowledge of air flow, Cabin air distribution and defrost.

Familiarity with vehicle testing and thermal instrumentation.

Experience with system-level integration and thermal controls

Education required:

Bachelor’s degree in mechanical engineering, Thermal Engineering, or related discipline.

Additional Information:

Opportunity for extension to contract

Outside IR35

Hybrid working

Eligibility:

You must have the right to work in the UK; sponsorship is not offered for this role