Page 164 - TransAT_Tutorial_Manual

TransAT Tutorial Manual 4.4. Film Boiling

4.4 Film Boiling

Please note: this tutorial makes use of Advanced Initial Conditions. Microsoft SDK is required
to run it.

4.4.1 Prerequisites

• TransAT
• TransATUI

• Advanced Initial Conditions

• Paraview (or Tecplot)

4.4.2 Introduction

In this tutorial film boiling of a liquid is modeled. A vapor layer spreads over the lower wall, which
is kept at a constant superheated temperature. The liquid is kept at the saturation temperature.
The heat transfer from the wall causes phase change from the liquid to vapor. The vapor film
grows in size and due to the subsequent hydrodynamics, a plume begins to form. As heat is being
transfered, the plume grows then detaches from the film. This test case is similar to the setup
from Gibou et al. (2007).

Note that for this problem, properties of the phases have been arbitrarily determined, in or-
der to reduce the computational time while still capturing the correct physical behaviors.

The problem setup is given as follows:

• Domain: 79 mm × 79 mm resolved by a mesh 72 × 72 × 1. The top is an outflow whereas
the bottom is a wall with a defined temperature.
3
• Liquid: ρ l = 200.0 kg/m , µ l = 0.1 kg/m.s, c p,l = 400.0 J/kg.K , λ l = 40.0 W/m.K.
3
• Gas: ρ g = 5.0 kg/m , µ g = 0.005 kg/m.s, c p,g = 200.0 J/kg.K , λ g = 1.0 W/m.K.
• Surface tension: σ = 0.1 N/m.

• In the initial conditions, the heated surface of 5 K is covered by a thin layer of vapor that
separates the fluid with a temperature of 0 K above the saturation temperature and a latent
heat of 10, 000 J/kg from the wall completely. A Rayleigh instability of the liquid–vapor
interface is triggered by gravity
p
λ = 2π 3σ/g (ρ v − ρ l ).

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