In this paper the effect of inclination angle on the
condensation heat transfer coefficient, pressure drop and flow
regime inside a smooth tube was investigated numerically. The
working fluid was R134a at a saturation temperature of 40°C.
The Volume of Fluid (VOF) multiphase flow formulation was
utilized to solve the governing equations. Simulations were
conducted at a heat flux of 5 kW/m2, at mass fluxes of 100 –
600 kg/m2.s, and the inclination angles were varied from
vertical downward to vertical upward. The simulation results
were successfully validated with the experimental data. The
results showed that an optimum downward inclination angle of
between -30° and -15° exists, for the heat transfer coefficients.
It was also found that the effect of inclination angle on the
pressure drop and void fraction became negligible at high mass
fluxes and vapour qualities.
Papers presented at the 13th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Portoroz, Slovenia on 17-19 July 2017 .