Accuracy of Duct Flow Calculations

The car development becomes more and more virtual. The climate team of the Volvo CFD Group uses CFD to develop ventilation system ducts and nozzles. One of the major tasks of the team is to evaluate duct systems, mainly in terms of air distribution and pressure drop. How to create the grid in these ducts and what turbulence settings to use needs to be investigated further.

The focus of this project involves wall functions and grid resolution of duct flows. The goal is to determine the sensitivity of the settings involved in a duct system flow calculation and to give input to the grid generation process. The project involves the following parts:

1) High-Reynolds calculation
The current method is to use a high-Reynolds grid. However, there is a strong need to better understand and investigate the available wall functions. Two different turbulence models will be investigated as well.

2) Low-Reynolds calculation
Using a low-Reynolds grid to perform duct calculations will be investigated. A comparison will be done between using a high-Reynolds grid and a low-Reynolds grid.

3) Meshing input
The thesis work will give input to how meshing of ducts should be performed in the future depending on duct geometry and mass flow. What turbulence model and which wall function that is best suited will be determined as well.

We want you to have good knowledge of general fluid mechanics/thermodynamics and experience of CFD computations. The work is for one student.

We want your application with a CV before 2004-04-30.