Simulation of a Chill-Down process

Lehrstuhl für Aerodynamik
Semesterarbeit / Masterarbeit /
theoretisch /  

For the main stage of space transportation systems mainly liquid rocket
engines with cryogenic liquid oxygen and hydrogen/methane as
propellant are used. Before the propellant is injected and burnt, it is used
for structural cooling. Around the combustion chamber cooling channels
are located, through which the propellant is pumped (fig. 1). After that,
the propellant together with the cryogenic oxidizer is injected into the
combustion chamber and burnt.
Before the rocket launch all engine components being in contact with
cryogenic liquids, have to be cooled down to saturation temperature.
This so-called chill down process has to be optimized with respect to
duration of the cool down and fuel consumption.

At the von Karman institue for fluid dynamics (VKI) experiments
with liquid nitrogen have already been conducted. For gaining a
deeper understanding, these cases should now be investigated via
RANS-simulations. The chill down comprises several steps from film
boiling over the Leidenfrost point and nucleate boiling to single
phase convection with heat transfer (fig. 2). These phases should be
identified in the simulation and compared to the experimental
results. At the inception of the film boiling large amounts of steam
are generated in a relatively short time due to the hot walls. This
leads to a short-term blocking of the channel. The blocking process
has a characteristic frequency, which can be identified in the
simulations and compared to the VKI-measurements.

  • Ability to work independently
  • Basic knowledge of numerical flow simulation
  • Knowledge of linux advantageous
  • Lectures: Angewandte CFD, fluid mechanics I, Fundamentals of multiphase flows
Möglicher Beginn
Alexander Doehring
Raum: MW 1676b
Tel.: +49 89 28916148