Isar Aerospace SE

New Space

FluidsEngineer(m/f/d)

Ottobrunn, Bavaria, Germany
The Brief

“Fluids Engineer (m/f/d) at Isar Aerospace SE. Skills: propellant management, pressurization systems, multiphase flow analysis, reusable launch vehicles. analyse propellant behaviour across changing thermal conditions, transient operating states, and mission phases including ascent, shutdown, coast, reentry, and relight. Define and analyse the overall propellant management architecture, including propellant location, acquisition strategy, residuals, depletion behaviour, and their interaction acro”

What You'll Achieve.

Your work directly drives propellant management, pressurization, and feed system design for next‑generation reusable launch vehicles.

Industry & Context.

New Space
Problems you'll solve

Structured, physics‑driven problem‑solving mindset; Critical judgement of model assumptions, numerical limitations, and validity ranges; balancing analysis fidelity, computational cost, and engineering timelines

Eligibility Requirements

Due to security clearance requirements, affiliations with countries listed under § 13 para. 1 no. 17 SÜG may affect the application process.

What They're Looking For.

Must Have

Degree in mechanical, aerospace, or chemical engineering, or a closely related field, fundamentals in fluid mechanics, thermodynamics, and cryogenic systems, Solid understanding of multiphase flow, including liquid–vapor interfaces and heat and mass transfer, 3–5 years of experience in propulsion, fluids, or propellant management related roles, Hands‑on experience analysing propellant behaviour at system or architecture level, not only single components, Practical experience with VOF or comparable multiphase modelling, including thermal effects and free‑surface behaviour, Exposure to microgravity or low‑acceleration propellant dynamics and their impact on system operability, Experience deriving or contributing to tank pressurization architectures, including transient behaviour, Experience abstracting high‑fidelity analysis into reduced order models for vehicle or program‑level trade studies, Ability to derive propellant management and pressurization architectures from mission requirements, operating envelopes, and reusability constraints, Capability to quantitatively assess trade‑offs between propellant management concepts using first‑principles analysis, scaling laws, and targeted high‑fidelity simulations, Critical judgement of model assumptions, numerical limitations, and validity ranges, Comfortable balancing analysis fidelity, computational cost, and engineering timelines, Clear communication of complex fluid behaviour to non‑fluids specialists, Structured, physics‑driven problem‑solving mindset, Fluent in English

Nice to Have

German is a plus

What You'll Do.

analyse propellant behaviour across changing thermal conditions

transient operating states

and mission phases including ascent

Define and analyse the overall propellant management architecture

including propellant location

and their interaction across mission phases

Analyse microgravity and low-acceleration propellant dynamics

including propellant surface behaviour modelled with VOF methods and coupled heat and mass transfer

to drive architectural choices

Derive tank pressurization concepts from mission requirements and reusability constraints

including transient behaviour across mission phases

Perform NPSP and inlet margin trades

including the influence of propellant thermal state and transient operating conditions on engine behaviour

Analyse propellant routing

including feedlines and valves

with focus on transients

Define pressurization and consumables architecture in the context of reusability

including sizing logic

and operational envelopes

Develop reduced order models from high‑fidelity analyses to support vehicle‑level and program‑level trade studies

How You'll Work.

Team & Collaboration

Clear communication of complex fluid behaviour to non‑fluids specialists

Communication Scope

Clear communication of complex fluid behaviour to non‑fluids specialists

Free ATS check

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