1. Research objectives
 Semi-analytical approach to predict the Wilson point for
arbitrary fluids
 Robust and computationally efficient numerical schemes for
design purposes
Characterization of Metastable
Condensation in High-Speed
Flows for arbitrary fluids
Background & Motivation:
Non-equilibrium condensation occurs in a wide range of industrial
processes (steam turbines, ORC power plants, carbon capture, etc.).
The formation of droplets lead to significant fluid-dynamic losses and
component damage.
• Components must be designed such that metastable condensation
is mitigated.
• Need of reliable models to predict the onset of condensation and the
droplet characteristics.
PhD Candidate: Lucia Azzini
Department: AWEP
Section: Flight Performance and Propulsion
Supervisor: M. Pini
Promoter: P. Colonna
Starting date: 01/06/2015
Funding: TUDelft Aerospace faculty
Email: L.Azzini@tudelft.nl
Type: CFD
AerospaceEngineering
Numerical methods
• Transport equations according to the method of
moments
• Calibration on available experimental data
Physical Understanding
• Investigation on steam supersonic expansions
• Wilson point redefinition: new time-dependent
approach
 More robust and efficient
 Simulation time < 2x single phase
 No two-phase simulation required
 Applicable to arbitrary fluids
1. Science
• Validated semi-analytical method
for steam and CO2 data
• Investigation on organic fluids
(R11, R21)
• Evaluation of the Wilson line for
arbitrary flows
2. Numerics
• Development of a multi-D
numerical model for metastable
condensation in the open-source
CFD code SU2
Final goal
• Design of turbomachinery
components
Deliverables:
References:
• Azzini, L., der Stelt, T. V., and Pini, M. , Numerical
investigation of metastable condensing flows with
an implicit upwind method.
• Azzini, L. and Pini, M. , Numerical investigation of
high pressure condensing flows in supersonic nozzles.
• Azzini, L. and Pini, M. , Semi-analytical approach for
Wilson point prediction in homogeneously condensing
steam flow.
• Gyarmathy, G., 2005. Nucleation of steam in high-
pressure nozzle experiments. Proceedings of the
Institution of Mechanical Engineers, Part A,
219(6), Jan, pp. 511-521, SAGE Publications
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