Principal Thermal Mechanical Engineer

Flex•Littleton, MA

2d•$153,500 - $211,000

About The Position

JetCool, a Flex company, develops liquid cooling solutions for AI and high-performance computing. The Principal Thermal Mechanical Engineer will support early product development and provide guidance as products mature. JetCool’s products support data-center sustainability by enabling higher coolant temperatures and more complete heat capture. Reporting to the Product Manager, this role provides technical leadership, mentorship, and hands-on expertise in mechanical design, fluid dynamics, and heat transfer. The engineer also works with customers to explain JetCool technology and build technical customer relationships. The position is located in Littleton, Massachusetts.

Requirements

Master’s degree in Mechanical Engineering or a related field; thesis required.
At least 7 years of post-collegiate experience designing and engineering fluid systems.
At least 3 years working at senior or principal engineer level in an industrial setting.
Profound expertise in fluid dynamics, thermodynamics, and heat transfer, with a strong foundation in engineering principles.
Extensive experience with SolidWorks CAD, complex part and assembly drawings, GD&T, and DFM.
Ability to independently develop product concepts, conduct performance analysis, and design experiments.
Strong analytical and problem-solving skills, including troubleshooting and optimizing fluid-system performance.
Excellent communication and documentation skills for conveying complex technical concepts to technical and non-technical audiences.

Nice To Haves

Fluid-system design experience in data-center thermal management or cooling, automotive, medical, or nuclear industries.
A track record of new product development, preferably involving thermal-fluid products.

Responsibilities

Lead the design, analysis, and optimization of complex liquid-cooling fluid systems, from initial CAD concepts through detailed CAD and drawings, including cold plates, pumps, fluids, tubing, and heat exchangers for computer processing chipsets.
Collaborate with customer and partner teams to integrate fluid systems into overall product designs.
Conduct fluid-flow simulations, analyses, and tests to evaluate system efficiency and reliability under varied operating conditions.
Calculate and analyze fluid dynamics, pressure drops, thermal performance, and material compatibility.
Develop and review engineering specifications and documentation for fluid-system and heat-transfer components and assemblies, ensuring compliance with industry standards and regulatory requirements.
Help maintain best practices and develop foundational knowledge and intellectual property through research.
Identify technical gaps, advocate for research and development, and lead research projects to maximize product impact and benefit.
Provide technical guidance and mentorship to junior engineers.
Participate in design reviews and present technical findings and recommendations to internal and external stakeholders.
Contribute to new product concepts and fluid-system design innovations, keeping abreast of industry trends and emerging technologies.
Support resolution of fluid-system technical challenges throughout the product lifecycle.