Fluids Analyst

Cowboy Space•Seattle, WA

10d•Onsite

About The Position

As a Fluids Analyst, you will own fluids prediction for the team — the models, the analysis, and the data that back every fluid system decision we make. You are accountable for the full lifecycle of that prediction: standing up early system models before hardware exists, sizing and trading architectures against pressure drop, flow capability, and thermal performance, then closing the loop by reducing test data and correlating it back into the models. You will work closely with fluids design, propulsion, thermal, structures, and test operations, and your predictions will directly set or verify component sizing, test objectives, and flight limits. This is a hands-on analysis role for someone who wants to be in the test bay watching the data come in, not just running cases. You’ll be expected to move quickly, iterate often, and take full ownership of the fluid models the team relies on.

Requirements

Bachelor’s degree in Mechanical Engineering, Aerospace Engineering, Chemical Engineering, or related field.
5+ years of experience performing fluid system analysis for flight vehicles, propulsion systems, or other high-performance hardware.
Strong fundamentals in fluid mechanics, thermodynamics, and heat transfer, including compressible flow, two-phase flow, and transient system behavior.
Experience building 1D fluid network or transient system models with tools such as Flownex, AFT (Fathom/Arrow/Impulse), EASY5, GFSSP, Simulink, or equivalent in-house codes.
Hands-on experience with commercial or open-source CFD (ANSYS Fluent, Siemens STAR-CCM+, or OpenFOAM) applied to internal flow problems.
Proficiency with Python (NumPy, pandas) or MATLAB for model development, data reduction, and automation of analysis workflows.
Experience reducing and interpreting real test data, including correlating analytical predictions against measurements.
Must be a U.S. citizen or national, U.S. permanent resident (current Green Card holder), or lawfully admitted into the U.S. as a refugee or granted asylum.

Nice To Haves

10+ years of experience performing fluid system analysis for flight vehicles, propulsion systems, or other high-performance hardware.
Direct experience with rocket engine, launch vehicle, or spacecraft propulsion fluid systems.
Experience with cryogenic fluids (LOX, methane, hydrogen, nitrogen, helium), including chill-in, two-phase transients, and thermal stratification.
Familiarity with real-fluid property libraries and equations of state (REFPROP, CoolProp, NIST data) and their limits of validity.
Experience analyzing valves, regulators, injectors, or turbopump feed systems, including flow-force and stability behavior.
Experience supporting propulsion hot-fire testing, cold-flow testing, or vehicle fill/drain operations with live analysis support.
Experience building automated data pipelines or analytics tooling over large test datasets.
Familiarity with uncertainty quantification, design of experiments, or statistical model calibration methods.
Experience with structural or thermal FEA (ANSYS, Nastran, Abaqus) for coupled fluid-structure or conjugate heat transfer problems.
Familiarity with relevant industry standards (AIAA S-080/S-081, ASME BPVC, SAE, and MIL-spec fluid system standards).
Experience at a fast-moving, hardware-focused startup or early-stage program.

Responsibilities

Own the full lifecycle of fluids prediction and data for the team — from first-order sizing models through correlated, test-anchored models used for flight.
Build and maintain 1D fluid network and transient system models of engine and vehicle fluid systems to predict pressure drop, flow capability, and thermal performance.
Perform early-phase simulation and trade studies to inform architecture selection, line and orifice sizing, valve and regulator selection, and pressurization schedules before hardware is committed.
Predict flow capability and pressure budgets across the system: line and fitting losses, flow distribution and manifold balance, cavitation and choked-flow margin, NPSH, and engine inlet conditions.
Analyze transient behavior — water hammer, priming and chill-in, valve sequencing, blowdown and ullage collapse, tank pressurization and thermal stratification.
Perform CFD analysis of valves, manifolds, and other internal-flow components to resolve loss coefficients, flow distribution, and local behavior that lumped models cannot capture.
Perform thermal-fluid analysis including two-phase and cryogenic behavior, heat leak, insulation performance, and conjugate heat transfer in fluid components.
Define the instrumentation and measurement requirements needed to validate your models — specify what gets measured, where, at what rate, and to what accuracy.
Support component-level and system-level test campaigns: write analysis-driven test objectives and predictions and set red lines and expected values.
Own reduction and analytics of fluids test data — build the data pipelines, automate processing across runs, quantify uncertainty, and turn raw channels into engineering quantities.
Correlate models against test and flight data, quantify model error, and drive the updates that improve predictive accuracy over time.
Establish and maintain the team's analysis methods, model libraries, fluid property data, and validation standards so results are repeatable and reviewable.
Perform anomaly investigation and root cause analysis using test and flight data; reconstruct off-nominal events and recommend corrective action.
Balance model fidelity against schedule — know when a hand calculation is sufficient and when the problem warrants CFD.
Communicate analysis results and their uncertainty clearly to designers, test engineers, and leadership, and document methods, assumptions, and conclusions in review-ready form.