Ksymena Wysocka
ECS Engineer · Thermal Engineering
Warsaw, Poland
ECS Engineer responsible for design and analysis of aircraft Environmental Control Systems, including bleed air extraction architecture, air cycle machine (ACM) design, cabin pressurization control, and thermal comfort analysis. Builds system-level ECS models in AMESim that support performance verification across the full operating envelope from ground hot-day soak to high-altitude cruise.
Expertise
- Environmental Control System (ECS) design
- bleed air systems and pneumatic architecture
- cabin pressurization and temperature control
- pack and air cycle machine modeling
- ECS performance analysis
Technologies
Work History
2025-02
ECS digital twin for in-service monitoring — provided AMESim model as basis for real-time ECS health monitoring. Worked with digital engineering team to reduce model to a real-time capable order.
Challenge: Full AMESim ECS model had 380 states — far too many for real-time execution. Model order reduction using singular perturbation (eliminating fast pneumatic states) reduced to 45 states while preserving accuracy to within 3°C on cabin temperature prediction.
Learned: ECS system model order reduction using singular perturbation is effective because pneumatic systems have a natural time-scale separation — fast pressure dynamics and slow temperature dynamics. Eliminating the fast states by quasi-static approximation is physically justified and produces a well-conditioned reduced model.
2024-05
Cabin pressurization control law design and verification — designed the outflow valve control law for cabin altitude management during climb, cruise, and descent. Verified against CS-25.841 cabin pressure altitude requirements.
Challenge: The differential pressure limit (0.575 bar) and rate-of-change limit (0.274 bar/min) are coupled constraints that required a control law with simultaneous ΔP and dΔP/dt limiting. A simple pressure controller violated the rate limit during rapid descents.
Learned: Cabin pressurization control law design must address coupled pressure level and rate-of-change constraints simultaneously. A cascade controller (outer: cabin altitude rate, inner: outflow valve position) handles both constraints naturally and is more robust than a single-loop ΔP controller with rate clamping.
2023-10
Pack flow control valve characterization — modeled the pneumatic and thermal behavior of the ECS pack flow control valve across the operating range. Defined the valve Cv vs. position curve and hysteresis specification.
Challenge: Pack valve hysteresis in the supplier test data was inconsistent — different test temperatures produced different hysteresis bands. Root cause: the valve seal material stiffness is temperature-dependent. Required temperature-dependent hysteresis specification in the valve procurement specification.
Learned: Pneumatic valve specifications must include temperature-dependent hysteresis requirements. A single hysteresis value at room temperature is insufficient for an ECS valve operating from -55°C to +90°C — the temperature dependence can change valve authority by 15%.
2023-04
ECS architecture trade study — compared high-pressure bleed (HP only) vs. dual-spool bleed (HP+LP) vs. electric ECS (no bleed) configurations for a new aircraft. Evaluated penalties on engine SFC, airfield performance, and system weight.
Challenge: Electric ECS (bleedless) showed 2.3% SFC improvement vs. HP bleed but added 180kg in electric motor, generator, and power electronics weight. The weight penalty eliminated most of the fuel burn benefit below 1,000 flight hours per year — break-even required fleet utilization analysis.
Learned: ECS architecture trades must include an operational lifecycle analysis — fuel burn vs. weight tradeoffs change sign depending on aircraft utilization rate. A ground truth from the customer's utilization profile is essential before committing to bleedless vs. bleed architecture.