Thermal - Fluids Analyst I

AntaresUSAFull Time1mo ago$90K - $150K

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Job description

About the role

Antares is seeking a Thermal

Fluids Analyst I to join the Reactor Hardware Engineering department at their Torrance, California headquarters. In this position, you will construct and execute computational fluid dynamics and thermal models for the R1 microreactor core and power conversion subsystems. Your analyses will directly inform design iterations, ensuring components satisfy stringent thermal, mechanical, and performance criteria under extreme operating conditions. You will partner closely with design engineers to provide rapid feedback on sizing, material selection, and pressure drop characteristics. Additionally, you will support test campaigns through pre-test planning, instrumentation specification, and post-test model validation to anchor simulation fidelity.

Key facts

Location: USA

Engagement: Full-time, on-site

Compensation: $90K - $150K base salary + equity (Engineer I: $90K-$115K; Engineer II: $112K-$150K)

What you'll do

Evaluate subcomponent designs for pressure drop, heat transfer coefficients, and thermal performance using hand calculations, proprietary internal tools, and commercial CFD solvers including conjugate heat transfer and compressible flow regimes.
Collaborate with mechanical designers and responsible engineers to establish initial sizing parameters, guide material selection, and deliver iterative design feedback derived from analytical results.
Author comprehensive technical documentation capturing analytical methodologies, boundary conditions, assumptions, and limitations for internal stakeholders and external regulatory customers.
Partner with test engineering teams to co-develop test objectives, specify instrumentation requirements, and perform root cause analysis on anomalies, ensuring test data effectively validates and anchors simulation models.
Develop and maintain automated internal calculators and scripting tools (Python, MATLAB, VBA) that empower non-specialist engineers to perform rapid analytical assessments without full finite element models.
Provide technical mentorship to junior engineers and cross-functional teammates on thermal-fluids modeling best practices and numerical methods.
Perform 1-D fluid network modeling using tools such as Flownex, SINDA/FLUINT, or RELAP5 to characterize system-level thermal-hydraulic behavior.
Support multiphase heat transport analysis for systems including heat pipes, Rankine cycle power conversion loops, and saturated cryogenic propellant storage.
Ensure analytical approaches align with ASME BPVC Section III Division 5 requirements for nuclear safety-class components.
Execute finite element analysis (FEA) for coupled thermal-structural assessments when required by design loads.
Participate in rapid design iteration cycles, delivering actionable data on aggressive timelines to support hardware build schedules.
Travel occasionally to support test campaigns, supplier reviews, or customer meetings at government facilities.

Requirements

Bachelor's degree in Mechanical Engineering, Aerospace Engineering, or a closely related technical discipline.
Demonstrated proficiency building and executing CFD models in commercial codes such as ANSYS Fluent, CFX, or Siemens Star-CCM+, specifically including conjugate heat transfer and compressible equation-of-state formulations.
Hands-on experience with CAD software (Siemens NX strongly preferred) for geometry cleanup, defeaturing, and design modification prior to meshing.
Competency in scripting languages (Python, MATLAB, or VBA) for automating workflows, post-processing results, and building engineering calculators.
U.S. Person status (U.S. citizen, lawful permanent resident, refugee, or asylee) required to comply with ITAR export control regulations.
Ability to work extended hours and weekends as necessary to support critical program milestones and hardware delivery schedules.

Nice to have

Master's degree in Mechanical Engineering, Aerospace Engineering, or relevant field.
Three or more years of professional experience performing thermal-fluids analysis in aerospace, nuclear, or high-performance energy systems.
Prior exposure to 1-D system-level thermal-hydraulic codes such as Flownex, SINDA/FLUINT, or RELAP5.
Experience supporting regulatory qualification or certification programs for safety-critical hardware in the nuclear (NRC/DOE) or aerospace (NASA/DoD) sectors.
Background implementing custom numerical methods or user-defined functions for fluid-dynamic and thermodynamic solvers.
Familiarity with multiphase flow and heat transport phenomena in heat pipes, two-phase Rankine cycles, or cryogenic fluid management.

Skills & tools

CFD: ANSYS Fluent, ANSYS CFX, Siemens Star-CCM+ (conjugate heat transfer, compressible flow)
1-D Thermal-Hydraulics: Flownex, SINDA/FLUINT, RELAP5
CAD: Siemens NX (preferred), geometry defeaturing and simplification
Scripting & Automation: Python, MATLAB, VBA
Structural Analysis: FEA (ANSYS Mechanical, Abaqus, or similar) for thermal-stress coupling
Standards: ASME BPVC Section III Div. 5, nuclear quality assurance (NQA-1) awareness
Version Control: Git, configuration management for analysis models

Practical notes

Role is based on-site at Antares' new 322,000 sq. ft. facility in Torrance, CA, with direct access to the 405, 105, and 110 freeways.
No relocation package is explicitly advertised; candidates should be local or willing to move at own expense.
ITAR compliance mandates U.S. Person status; visa sponsorship (H-1B, O-1, TN, etc.) is not available for this position.
Compensation tier (Engineer I vs. Engineer II) will be determined during the interview process based on experience depth and scope of prior responsibility.
Equity component is included in the total compensation package alongside the base salary bands.
Company founded in 2023; team includes alumni from SpaceX, Relativity Space, Ursa Major, General Atomics, National Labs (LANL, INL, ORNL), and government service.
Over $600M in venture capital raised and $13M+ in government contracts secured, indicating strong runway.
Culture emphasizes first-principles systems thinking, end-user obsession, unconventional solutions, in-person collaboration, and comfort with ambiguity.