Fluid Dynamics Engineer

ABOUT FUSE We are building one of the most potentially consequential companies of the century. Our mission is to accelerate the world's transition to fusion energy while safeguarding humankind. This is not a normal company. This is not a normal job. We are committed for the long term to win. ABOUT THE ROLE Fuse is designing and constructing Z-Star, a next-generation pulsed-power accelerator requiring the management, recirculation, filtration, and conditioning of multi-million-liter volumes of high-voltage transformer oil and deionized (DI) water. As the Fluid Dynamics Engineer, you'll lead the design, simulation, and operational integration of these large-scale fluid systems from concept through commissioning. CORE RESPONSIBILITIES - System Design: Design and develop large-scale fluid circuits for storing, transporting, recirculating, and reconditioning millions of liters of transformer dielectric oil and deionized water, including pump selection, piping layout, filtration trains, heat exchangers, and storage-tank configuration. - CFD Simulation: Build and run high-fidelity Computational Fluid Dynamics models of oil and DI-water flow paths to optimize circulation rates, identify cavitation or turbulence risks, and ensure dielectric integrity under operational conditions. - Dielectric Fluid Management: Develop and maintain fluid-quality protocols including oil breakdown-voltage testing, moisture-content control, and particle filtration, consistent with high-voltage pulsed-power standards. - DI Water Conditioning: Design and oversee the mixed-resin-bed ion-exchange system to maintain DI-water resistivity, dissolved-gas content, and temperature within operational limits. - Thermal Analysis: Perform thermohydraulic analyses to quantify heat loads from repeated pulsed discharges and design cooling strategies that maintain fluid properties within required dielectric specifications. - P&ID and Documentation: Develop Piping and Instrumentation Diagrams (P&IDs), system schematics, bills of materials, and operational procedures for all fluid subsystems. - Commissioning and Troubleshooting: Support fabrication, testing, and commissioning of fluid systems on-site; diagnose and resolve operational anomalies during early shot campaigns. - Interdisciplinary Collaboration: Work closely with pulsed-power, high-voltage, structural, and vacuum engineering teams to ensure fluid-system integration with electrode geometry, transmission lines, and chamber design. MINIMUM QUALIFICATIONS - B.Sc.or M.Sc. in Mechanical Engineering, Chemical Engineering, or Applied Physics with a strong fluid-mechanics concentration. - Demonstrated experience with commercial or open-source CFD tools such as ANSYS Fluent, ANSYS CFX, OpenFOAM, or COMSOL Multiphysics. - 2+ years designing or operating large-scale industrial fluid systems including pumps, filters, heat exchangers, and piping networks in energy, nuclear, defense, or high-voltage environments. - Familiarity with transformer oil or similar dielectric insulating fluids, including properties, degradation mechanisms, filtration, and electrical testing. - Strong command of convective and forced-flow heat transfer for system-level thermal management. PREFERRED QUALIFICATIONS - Experience with deionized-water systems, ion-exchange resin beds, degassing, and resistivity monitoring in high-voltage or pulsed-power environments. - Knowledge of pulsed power, particle accelerators, fusion energy, or high-energy-density physics facilities. - Knowledge of ASME piping codes, industrial safety standards, and high-voltage facility regulations. - Proficiency in Python for post-processing simulation data and automating fluid-quality reporting. WHAT WE VALUE - Give a shit. Build things you're proud of. - Take responsibility. If something is broken and you can fix it, fix it. See things through. - Move fast. Make decisions, learn quickly, and keep moving forward. - Think bigger. Simplify relentlessly. Don't default to the safe answer. - Disagree and commit. The best idea wins. Once a decision is made, we move. - Desire to win. This is hard. Expect intensity. We are here to win. - Plan B is to make Plan A work. ADDITIONAL REQUIREMENTS This is not a remote position and will require relocation if not already local to the applicable Fuse facility. BENEFITS - Medical, dental, and vision coverage. - Relocation assistance for roles that require it. - Flexible time off. Take what you need, no accrual tracking. - 2 weeks of paid time off built into the end of each year, subject to team and business needs. - Supportive leave of absence policies. - Paid leave for new parents. ITAR REQUIREMENTS To conform to U.S. Government technology export regulations, including the International Traffic in Arms Regulations (ITAR), you must be a U.S. citizen, lawful permanent resident of the U.S., protected individual as defined by 8 U.S.C. 1324b(a)(3), or eligible to obtain the required authorizations from the U.S. Department of State. EQUAL OPPORTUNITY Fuse is an Equal Opportunity Employer; employment with Fuse is governed on the basis of merit, competence, and qualifications and will not be influenced by race, color, religion, gender, national origin/ethnicity, veteran status, disability status, age, ancestry, immigration status, sexual orientation, gender identity, marital status, mental or physical disability, or any other legally protected status.