Andrzej Dąbrowski
Turbomachinery Engineer — Turbine · Propulsion Engineering
Warsaw, Poland
Turbomachinery Engineer focused on HPT and LPT aerodynamic design and analysis. Has deep expertise in cooled turbine aerothermal CFD, secondary air system modeling for turbine rim sealing and tip clearance, and multi-stage turbine performance optimization. Works closely with thermal and structural teams to translate aerodynamic requirements into manufacturable cooling designs.
Expertise
- HPT and LPT aerodynamic design
- turbine stage efficiency optimization
- secondary air system modeling
- turbine tip clearance control
- cooled vane and blade aerothermal CFD
Technologies
Work History
2024-10
Turbine acoustic analysis — quantified HPT tone noise generated by rotor-stator wake interaction using ANSYS CFX broadband noise sources model. Provided acoustic forcing data for nacelle noise prediction team.
Challenge: Turbine tone noise prediction requires accurate wake decay prediction in the inter-stage gap, which RANS models underpredict due to excessive turbulent diffusion. Needed scale-resolving SAS-SST model for the inter-stage region, significantly increasing compute cost.
Learned: For turbine tone noise prediction, standard RANS wake models are insufficient — the wake mixing rate is too aggressive, leading to underestimated acoustic forcing. Scale-resolving approaches are necessary for credible turbine noise assessments.
2024-02
LPT efficiency deterioration assessment for in-service engines — correlated CFD tip clearance sensitivity predictions against borescope-measured clearances from 40 engines. Built predictive deterioration model.
Challenge: Borescope measurements of tip clearance in service have high uncertainty (±0.15 mm) due to measurement geometry constraints. Had to treat clearance as a probabilistic input and quantify efficiency deterioration as a distribution rather than a point estimate.
Learned: In-service analysis must account for measurement uncertainty. Monte Carlo propagation of borescope measurement error through the CFD surrogate was essential to produce meaningful confidence intervals on the efficiency deterioration estimate.
2023-09
Secondary air system (SAS) modeling for HPT rim seal — quantified hot gas ingestion as a function of purge flow fraction using ANSYS CFX transient sector model with rim seal geometry.
Challenge: Rim seal ingestion is driven by the unsteady interaction between the main gas path and the wheelspace — RANS steady-state significantly underestimates ingestion. Required URANS time-marching, which was 15x more expensive per operating point.
Learned: Rim seal ingestion cannot be captured with steady CFD. Budget for URANS from the start for any secondary air system study where hot gas ingestion is a risk — the additional compute cost is justified to avoid non-conservative purge flow margin estimates.
2023-03
HPT stage 1 aerodynamic analysis — optimized nozzle guide vane (NGV) trailing edge shape to reduce profile loss while maintaining adequate cooling slot exit conditions. Ran a 24-design CFD sweep using ANSYS CFX mixing-plane.
Challenge: The trailing edge coolant ejection creates a blockage effect that changes the aerodynamic loss in a non-linear way. Minimizing profile loss while keeping coolant ejection effectiveness above 0.6 required a multi-objective formulation — single-objective optimization consistently sacrificed one of the two.
Learned: Cooled turbine aerodynamic design is inherently multi-objective. Setting up the optimization as a true Pareto front exploration (NSGA-II) from the beginning avoids the convergence to sub-optimal single-objective solutions.