Liquid Cooling Mechanical Engineer

Accelsius, LLC•Austin, TX

3d•Onsite

About The Position

Accelsius is developing revolutionary direct-to-chip, 2-Phase cooling technologies to address the growing heat management challenges in data and edge computing centers driven by increasing data service demands. We are seeking a Liquid Cooling Mechanical Engineer to design server-level liquid cooling hardware for AI and HPC platforms. This role involves taking designs from initial prototype through production release, ensuring manufacturability, and collaborating with R&D technicians for validation. The engineer will work on cold plate loops, server plumbing, manifolds, and pressure-containing assemblies, reporting to the Server Cooling Product Manager. The ideal candidate is hands-on, self-directed, and capable of managing designs across engineering, manufacturing, supplier, and customer teams.

Requirements

5+ years of experience with progressively increasing responsibility
Bachelor’s degree in mechanical engineering or similar required
Direct experience designing liquid cooling hardware for data center servers or racks required (single-phase or two-phase)
Demonstrated design of pressure-containing fluid systems: joint design, fitting selection, material selection, pressure rating, and leak testing
Working knowledge of fluid mechanics and heat transfer sufficient to collaborate with thermal engineers on sizing and performance; CFD and thermal specialization not required
Proficiency in a parametric 3D CAD tool (SolidWorks preferred) and producing manufacturing drawings with GD&T
FEA experience evaluating structural deformation and stress in mechanical parts
Record of taking designs through fabrication and release with external suppliers
Takes ownership, communicates clearly, and works across disciplines

Nice To Haves

Startup experience is a plus
Working with cold plate vendors and brazing manufacturers
HVAC, refrigeration, or hydronic systems design
Cold plate and fluid-component manufacturing processes: brazing, skiving, friction stir welding, machining
Familiarity with OCP liquid cooling specifications, ASHRAE liquid cooling guidelines, and IEC/UL 62368-1 requirements for liquid-filled components
ECO and configuration management in a PLM system

Responsibilities

Review thermal engineers’ concept and first-prototype designs to confirm a path to manufacturability
Translate first-prototype server liquid cooling assemblies for GPU and CPU platforms into production-ready designs, including cold plate loops, tubing and hose routing, manifolds, fittings, and quick disconnects, within the space, serviceability, and interface constraints of OEM server chassis
Design pressure boundaries: select materials, joining methods, and fittings; establish design, proof, and burst pressures; confirm compatibility with the working fluid
Partner with thermal engineers on plumbing sizing, pressure drop, and flow distribution, contributing packaging constraints, component selection, and manufacturability input to their analysis
Perform FEA to evaluate deformation and stress in pressure-containing parts and assemblies
Produce production-ready 3D models, drawings with GD&T, and BOMs; manage revisions through ECOs in our PLM system
Work with cold plate suppliers, braze shops, and fabricators from RFQ through first article; drive DFM and resolve supplier issues
Lead design reviews and mentor early-career engineers on server plumbing design
Support OEM and customer engagements with integration drawings and interface specifications
Define test requirements and acceptance criteria for pressure, leak, flow, and pressure drop testing
Define requirements for test fixtures and hardware, and review the manufacturing team’s fixture designs against them
Support R&D technicians in building and running tests on our R&D test rigs
Review test data, lead root cause investigations on failures, and carry findings into the next design revision