Sr. Heat Exchanger Engineer

• Own the thermal-hydraulic design of compact heat exchangers across the Arbor power system—high- and low-temperature recuperators, precoolers, and heaters—from conceptual sizing through detailed design, balancing effectiveness, pressure drop, mass, and cost.
• Serve as technical lead with suppliers of advanced compact heat exchangers, including additively manufactured and printed circuit (diffusion-bonded) units: define requirements and specifications, lead design reviews, and own qualification and acceptance testing.
• Lead in-house design and development of additively manufactured heat exchangers in high-temperature nickel alloys (e.g., Inconel 625, Haynes 282), applying design for additive manufacturing (DfAM) to channels, headers, and manifolds.
• Plan and run print and flow trials—from coupons through subscale cores—to characterize geometry, surface finish, and process effects, and anchor thermal-hydraulic and pressure drop models to the data.
• Own the thermal-mechanical life case for high-temperature heat exchangers—pressure containment, thermal transients, creep, and fatigue—working with mechanical and pressure vessel engineers on ASME code compliance.
• Plan and execute thermal and hydraulic performance testing on development and plant hardware: define instrumentation, write test procedures, lead data reduction, and close the loop between test results and design.
• Specify and technically manage conventional heat exchangers (shell-and-tube, air-cooled) per TEMA and API 661 as balance-of-plant needs arise.
• Generate and maintain the full engineering documentation package: thermal and mechanical calculation packages, drawings, material and process specifications, and test reports.

Requirements

• Bachelor's degree in Mechanical, Chemical, Aerospace, or related Engineering field.
• 6+ years of experience designing, building, and testing high-performance thermal-fluid hardware—heat exchangers, recuperators, precoolers, regeneratively cooled components, or similar.
• Demonstrated thermal-hydraulic design of compact heat transfer hardware—additively manufactured, printed circuit, plate-fin, microchannel, or regeneratively cooled—including channel geometry selection for performance, pressure drop, and manufacturability.
• Hands-on manufacturing experience with processes that form internal flow passages—metal additive manufacturing (laser powder bed fusion or similar), vacuum brazing, or diffusion bonding—including process troubleshooting, inspection, and defect disposition.
• Track record of taking full-scale hardware—flight, production, or industrial—from design through fabrication and test, and using test data to correct your models and designs.
• Ability to build first-principles thermal-hydraulic models (e.g., segmental ε-NTU with variable fluid properties) in Python, MATLAB, or similar.
• Working knowledge of pressure-containing and elevated-temperature structural design—thermal stress, creep, and fatigue—sufficient to drive a life assessment with support from specialists.
• Track record of making consequential technical decisions with incomplete information, owning the outcome, and moving fast in a small team.

Preferred Qualifications

• Experience with supercritical CO₂ or other supercritical or dense-phase fluids, including cryogenic propellants.
• Experience designing or qualifying printed circuit or other diffusion-bonded heat exchangers.
• Experience qualifying AM parameter sets, HIP and heat treatment, and powder removal for parts with internal passages.
• Experience specifying conventional heat exchangers per TEMA and API 661; proficiency with HTRI or equivalent.
• Familiarity with ASME Boiler and Pressure Vessel Code Section VIII as applied to heat exchangers.
• Background in startup, aerospace, or first-of-a-kind hardware development environments.

Benefits & Compensation

• Pre-IPO stock options
• Medical, dental, and vision insurance (Arbor covers 90% for employees)
• Basic life insurance fully covered
• Health savings account (HSA) with matching
• Flexible savings account (FSA)
• Unlimited PTO  
• 12+ company holidays, including Earth Day!  
• 401(k)
• Commuter benefits
• Annual learning and development stipend
• And more!

Base Pay: $165,000 - $180,000 USD/year. The salary is subject to the applicant's skills, qualifications, experience, and geographic location.