{"id":763863,"url":"https://alion.io/job/arborenergy-sr-thermodynamics-performance-engineer","title":"Sr. Thermodynamics Performance Engineer","company":{"id":669165,"name":"Arborenergy","domain":"arborenergy.com","url":"https://alion.io/company/arborenergy","size_band":null,"is_staffing_agency":false,"is_intermediary":false,"ats_vendor":"Greenhouse","truth_index":{"grade":"C","score":58,"open_postings":13,"ghost_share":0.692,"stale_share":0,"repost_share":0,"time_to_fill_p50_days":null,"computed_at":"2026-09-23T05:45:00Z"}},"role":"Backend","role_family":"Backend","seniority":"senior","employment_type":null,"work_mode":"on_site","remote_scope":null,"hiring_geo_confidence":"structured","locations":["El Segundo, United States"],"countries":["US"],"hiring_countries":[],"hiring_countries_total":0,"salary":{"min":165000,"max":180000,"currency":"USD","period":"year","gross":null,"usd_annual":180000},"salary_estimate":null,"experience_years_min":6,"visa_sponsorship":false,"relocation_package":false,"has_equity":true,"technologies":[{"name":"Digital Twin","optional":false},{"name":"MATLAB","optional":false},{"name":"Python","optional":false},{"name":"Simulink","optional":false}],"status":"live","first_seen_at":"2026-05-14T16:56:01Z","employer_posted_date":"2026-08-26","last_verified_at":"2026-09-23T23:44:42Z","board_verified":true,"closed_at":null,"days_open":132,"trust":{"level":"ghost","repost_count":0,"flags":["stale","company_stale"],"days_open":131},"description":"About Us\nAt Arbor Energy & Resources Corporation (\"Arbor Energy\"), we’re creating technology to power our lives while protecting the planet that sustains them. Our advanced power systems deliver clean, reliable baseload electricity with zero operating emissions-modular, fuel-flexible, and engineered for the realities of today’s energy demand. At the core is a supercritical CO₂ turbine with integrated carbon capture, designed to bring carbon-neutral power online quickly at meaningful scale. \nOur team includes aerospace engineers, combustion experts, and systems thinkers with a shared goal: to build technology worthy of the world we want to live in. While many of us began our journeys looking to the stars, we’re applying that expertise here at home to deliver dependable, emission-free baseload power and a future of lasting abundance. \nIf you share our values and are drawn to rigorous work with lasting impact, we’d love to learn more about you. Come build what the future will run on.\nSteward our planet: We build for tomorrow, ensuring every bolt we tighten and every hand we lend leaves our environment stronger than we found it.\nLead with Love: We champion the success of our people, partners, and planet, nurturing excellence through camaraderie and rigor.\nExplore the Uncharted: We embrace the unknown with curiosity, using courage and discipline to transform uncertainty into opportunity.\nRole Overview\nWe're looking for aSr. Thermodynamics Performance Engineer to own the dynamic and steady-state thermodynamic models of our direct-fired supercritical CO₂ Brayton cycle. You'll be the person who turns integrated system behavior into clear, actionable insight - running performance studies ahead of test campaigns, reconciling predictions against test data, and growing our modeling capability into a digital-twin-quality simulation platform that supports controls development, trip response, and eventual hardware-in-the-loop testing. You'll work closely with our test, combustion, turbomachinery, recuperator, fluid systems, and controls engineers. This is the simulation backbone for a first-of-a-kind power system, and the work is foundational to how we operate, validate, and scale the technology.\nThis is an onsite opportunity in our El Segundo, CA office. \nResponsibilities\nOwn the integrated cycle performance model - steady-state and dynamic - for our direct-fired sCO₂ Brayton power loop, maintaining and advancing it through the hardware lifecycle\nRun performance prediction and sensitivity studies ahead of test campaigns; reconcile model output against test data to drive model refinement and surface component-level insights\nOwn the architecture call on how our dynamic modeling stack should evolve over time - what platform, what fidelity, on what evidence\nBuild property tables, turbomachinery map handling, heat exchanger transient models, and combustor representations appropriate to the cycle and fidelity required\nCollaborate with combustion, turbomachinery, and heat exchanger engineers to integrate component data into system-level models; collaborate with controls and software teams on closed-loop simulation and HIL planning\nDevelop simulation infrastructure - scripted scenario runs, parameter sweeps, validation cases - that makes the model usable by engineers beyond yourself\nRequirements\nBachelor's degree in Chemical, Mechanical, Aerospace, Nuclear, or related Engineering field\n6+ years of experience in cycle performance analysis, thermodynamic systems modeling, or dynamic process simulation\nStrong fundamentals in thermodynamics, fluid mechanics, and heat transfer, applied to integrated multi-component systems\nDemonstrated experience building dynamic simulation models of fluid/thermal systems in an industry-grade 1D system simulation platform - and a clear point of view on tool tradeoffs for closed-loop power cycle applications\nWorking knowledge of integrated power loop equipment - heat exchanger sizing, compressor/pump curves, valve Cv, piping hydraulics - and how each shows up in dynamic response\nProgramming proficiency: Python for data reduction and automation; one of MATLAB/Simulink, Modelica, or equivalent for modeling\nStrong ownership mentality and comfort driving rigorous analysis in a fast-paced startup environment\nPreferred Qualifications\nDeep experience with industry dynamic simulation platforms (such as GT-SUITE, Modelica/Dymola, NPSS, Flownex, Simcenter Amesim, or equivalent) applied to turbomachinery, power cycles, or closed-loop thermal-fluid systems\nBackground in nuclear thermal-hydraulics with fast-dynamic single-phase modeling experience (RELAP, TRACE, MARS, ATHLET, GAMMA, or equivalent), particularly applied to gas-cooled or sCO₂ reactor concepts\nWorking knowledge of real-fluid EOS handling (REFPROP, CoolProp, Span-Wagner) and turbomachinery map interpolation near critical conditions\nHistory of making and defending tool/methodology decisions in a constrained engineering environment\nExperience with supercritical CO₂, closed Brayton cycles, high-pressure systems (100+ bar), or other high-density working fluids\nExperience coupling plant models to control systems for HIL testing, controller validation, FMU export, or operator training simulators\nHands-on plant startup, commissioning, or field troubleshooting on first-of-a-kind or developmental systems\nBackground in rocketry, gas turbine, advanced reactors, or high-performance turbomachinery environments\nCompensation & Benefits\nPre-IPO stock options\nMedical, dental, and vision insurance (Arbor covers 90% for employees)\nBasic life insurance fully covered\nHealth savings account (HSA) with matching\nFlexible savings account (FSA)\nUnlimited PTO \n12+ company holidays, including Earth Day! \n401(k)\nCommuter benefits\nAnnual learning and development stipend\nAnd more!\nBase Pay: $165,000 - $180,000 USD/year. The salary is subject to the applicant's skills, qualifications, experience, and geographic location.\nOur Commitment\nArbor Energy is proud to be an equal opportunity employer. We evaluate qualified applicants without regard to race, religion, national origin, gender identity or expression, sexual orientation, age, marital or veteran status, disability, or any other protected characteristic under applicable law. Solving global energy challenges requires a wide range of perspectives and experiences, and we are committed to building a team that reflects the world we serve.\nOur hiring process is designed to be accessible, fair, and focused on the work that matters most for this role. Reasonable accommodations are available throughout the hiring process and employment-please let us know if you need one.","description_format":"text","description_chars":6665,"description_truncated":false,"requirements":{"experience_years_min":6,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":{"level":"bachelor","optional":false},"security_clearance":false,"languages":[]},"benefits":["Life insurance","Stock options","Unlimited PTO","Vision insurance"],"hiring_locations":[],"hiring_excludes":[],"relocation_offered":false,"industries":["Chemical Engineering"],"lifecycle":[{"event":"open","at":"2026-09-11T19:21:39Z"}],"liveness":{"score":5,"band":"cold","label":"Long shot","p_open":1,"p_active":0.189,"p_room":0.28,"age_days":131,"expected_fill_days":26,"reasons":["conf:0","stale_co","ghost","win:tail","crowd:"],"computed_at":"2026-09-23T05:45:00Z"},"pay":{"stated_usd_annual":180000,"is_top_pay":false},"html_url":"https://alion.io/job/arborenergy-sr-thermodynamics-performance-engineer","json_url":"https://alion.io/job/arborenergy-sr-thermodynamics-performance-engineer.json","meta":{"generated_at":"2026-09-24T01:17:32Z","cache_seconds":300,"methodology":"https://alion.io/methodology","terms":"https://alion.io/terms","contact":"https://alion.io/contact","api":"https://alion.io/developers"}}