- Docente: Ruben Scardovelli
- Credits: 6
- SSD: ING-IND/19
- Language: Italian
- Moduli: Ruben Scardovelli (Modulo 1) Sandro Manservisi (Modulo 2)
- Teaching Mode: Traditional lectures (Modulo 1) Traditional lectures (Modulo 2)
- Campus: Bologna
- Corso: Second cycle degree programme (LS) in Energy Engineering (cod. 0455)
Learning outcomes
This course is designed to give a rudimentary exposure
to the thermo-fluid transport phenomena in two-phase systems, as
well as guide the students to formulate and solve problems
associated with the change-of-phase phenomena such as boiling
and condensation.
Furthermore the course is going to investigate different
numerical techniques and numerous industrial applications of
the two-phase transport theory.
Course contents
Introduction: Review of fundamental thermodynamic principles.
Coordinate systems. Basic mathematical operators. Transport
equations: mass, momentum, energy.
Physics of interfaces: Interfacial region. Surface tension.
Thermodynamics analysis of surface tension. The Navier-Stokes
surface tension term. Wetting phenomena. Contact angle and boundary
conditions. Interfaces. Transport boundary conditions for one-fluid
one-velocity and two-velocity model. Stability of the interfaces.
Kelvin-Helmholtz instability. Rayleigh-Taylor instability.
Isothermal two-phase flow: Two-phase two-fluid model.
Monodimensional two-fluid model. Mixed equations for the
monodimensional two-fluid model. Two-phase regime maps for
horizontal and vertical pipes. The homogeneous model. The
heterogeneous model. Determination of the two-phase multipliers and
void fraction. Martinelli-Nelson-Lockhart model. Boroczy
model.
Physics of phase change: Metastable states, phase stability and
spinodal curve. Homogeneous and heterogeneous nucleation. Bubble
growth in a superheated liquid. Pool boiling: regimes, models and
correlations. External condensation: dropwise and film
condensation.
Non-isothermal two-phase flow: Convective boiling in tubes and
different regimes. Subcooled and saturated boiling, critical heat
flux conditions. Internal convective condensation and different
regimes.
Readings/Bibliography
Liquid-vapor phase-change phenomena. V.P. Carey. Series in Chemical
and Mechanical Engineering. H.P.C. (1992)
Instructor notes
Teaching methods
A few lectures and exercises will be supported with software
demo.
Assessment methods
A written final exam followed by a discussion with the
instructors
Teaching tools
Lectures and exercises are in part with PC. A few videos will be
also shown.
Office hours
See the website of Ruben Scardovelli
See the website of Sandro Manservisi