Wall roughness modeling under transcritical conditions

Lehrstuhl für Aerodynamik
Semesterarbeit / Masterarbeit /
theoretisch /  

Liquid Rocket Engines (LRE) face extreme thermal conditions during
the operation time. High combustion temperatures up to 3600 K
combined with a high combustion chamber pressure up to 20 MPa imply
an effective cooling system. A regenerative cooling system uses the
cryogenic propellant for structural cooling by routing the the coolant
through small cooling channels within the combustion chamber wall
(fig. 1). After that, the propellant together with the cryogenic oxidizer is
injected into the combustion chamber.

The prediction of heat transfer at the combustion chamber wall is a
crucial for performance as well as for safety reasons and is affected by
many factors, as for example the cooling channel roughness.
In order to study the effects of roughness on the heat transfer and the
flow dynamics CFD simulations are a powerful tool. Figure 2 shows a
mean velocity shift compared to a smooth wall due to a momentum
deficit which depends on the roughness height. These results are
obtained using our in-house code CATUM, which solves the compressible
Navier-Stokes equations using a LES approach. Three different roughness
models are already implemented in a wall model that is applied in the
near wall area. All three models are in good agreement with ideal gas
experimental data but they are failing in flows with strong property
variations (real gas effects).

  • Ability to work independently
  • Basic knowledge of numerical flow simulation
  • Good knowledge of thermodynamics and gasdynamics
  • Basic knowledge of Fortran
  • Knowledge of linux advantageous
Möglicher Beginn
Alexander Doehring
Raum: MW 1676b
Tel.: +49 89 28916148