Senior Propulsion Engineer - Combustion Devices

Location: Parsdorf, Bavaria, Germany; onsite role.

Company

hirify.global develops launch solutions for small and medium-sized satellites and constellations to enable access to Low Earth Orbit.

What you will do

• Own CFD analyses of reacting flows in liquid rocket engine combustion devices from model definition and meshing through verification, validation, and technical recommendations.
• Develop and apply premixed, partially premixed, and non-premixed combustion models for rocket-relevant propellant systems and operating conditions.
• Perform RANS/URANS and, where justified, LES simulations to investigate mixing, ignition, flame stabilisation, combustion efficiency, and unsteady heat release.
• Model injector and chamber flows, including atomisation, evaporation, multiphase effects, real-gas behaviour, conjugate heat transfer, and wall heat flux where relevant.
• Assess combustion stability and operability, including flame dynamics, pressure oscillations, injector coupling, acoustic interaction, chugging, and high-frequency instability risks.
• Correlate simulations with component, cold-flow, and hot-fire test data; support design convergence, technical reviews, validation planning, and cross-functional issue resolution.

Requirements

• MSc or PhD in aerospace engineering, mechanical engineering, chemical engineering, computational engineering, or a comparable technical discipline.
• Typically 5–10 years of professional experience in rocket propulsion, with substantial hands-on responsibility for combustion CFD and combustion-device development.
• Deep knowledge of combustion physics, chemical kinetics, flame structure, turbulence–chemistry interaction, ignition, and extinction phenomena.
• Demonstrated experience modelling reactive premixed and non-premixed flows under rocket-engine-relevant pressure, temperature, and mixture-ratio conditions.
• Advanced proficiency in Simcenter STAR-CCM+ and/or Ansys Fluent for complex reacting-flow simulations, including meshing, solver selection, convergence assessment, and post-processing.
• Strong understanding of liquid rocket engine combustion devices, particularly injectors, preburners or gas generators, main combustion chambers, igniters, and associated thermal environments.
• Experience with CFD verification and validation, mesh and time-step sensitivity, uncertainty assessment, and correlation with experimental or hot-fire data.
• Proficiency in Python, MATLAB, or a comparable language for automation, data reduction, and engineering analysis.
• Strong technical ownership, first-principles judgement, clear communication, and professional fluency in English.

Nice to have

• Experience with LES or other scale-resolving methods for combustion dynamics, instability, and injector–chamber coupling.
• Experience with spray combustion, atomisation, evaporation, real-fluid or real-gas thermodynamics, conjugate heat transfer, radiation, or reacting multiphase flows.
• Experience supporting rocket-engine hot-fire campaigns, defining instrumentation needs, and diagnosing combustion anomalies from test data.
• Experience developing custom models, user-defined functions, reduced chemical mechanisms, HPC workflows, or automated CFD pipelines.

Culture & Benefits

• Virtual company share program.
• 30 days of vacation and a company pension plan with a 20% employer contribution after the probation period.
• Subsidised daily lunches and rental workwear with laundry service.
• Sponsored sports club memberships and an individual learning budget after the probation period.
• Childcare allowance and a flexible mobility budget covering options such as the Deutschlandticket, JobRad, JobAuto, or fuel allowance.