The Interaction Between Two 2D Rarefied Vapor Jets

The Interaction Between Two 2D Rarefied Vapor Jets

Broeders, Theo (TU Delft Electrical Engineering, Mathematics and Computer Science; TU Delft Applied Sciences)

Kleijn, Chris (mentor)
Vermolen, Fred (mentor)
Dubbeldam, Johan (graduation committee)
Kenjeres, Sasa (graduation committee)
Vesper, Elin (mentor)

Delft University of Technology

Applied Mathematics | Applied Physics

2019-04-09

Steel is commonly coated to protect it from corrosion. One method of applying this is by using Physical Vapor Deposition, which can be done by using multiple jets. In this process jets next to each other interact. This paper's main aim is to investigate the interaction effect of two rarefied two-dimensional vapor jets in vacuum and how this is influenced by the distance between jets and inlet density. Furthermore, the analytical solution for the collisionless case for a single jet is extended to dual jets. Additionally, the objective is to maximize the processing speed for the use of coating, with a certain uniformity for the parameters researched in this paper and finding an optimal method in doing so. This study is done by using the Direct Simulation Monte Carlo (DSMC) method.
The analytical solution gave the same results as the collisionless DSMC method for both single and dual jets. Simulations with a strong interaction effect resulted in a shock. These behaved similar compared to three-dimensional jets, in the plane of the jets. The shock results in a secondary jet, which has a lower density in the middle. The interaction effect depends primarily on the inlet density. Multiple regimes are observed for different inlet density ranging from small change in properties to a shock wave, with a transitional regime inbetween. The influence of the distance between the jets is found to result in a higher density at the axis of the inlet behind the shock, for bigger distance between jets. However, for very small distances between jets compared to the inlet size the shock is weak. For the optimization, it resulted in the conclusion that the optimal coating in general is applied with the smallest distance between jets. This generally gives a better uniform coating and increased performance. However, this is not always the case when constraining the distance between the jets and sheet, as it only holds if the shock between the jets for this distance. Furthermore, an approximation is found for the optimization, which results in fewer simulations needed.

Vapour deposition
DSMC
OpenFOAM

http://resolver.tudelft.nl/uuid:a3b1f704-c389-4160-9e19-2d30879a411f

Student theses

bachelor thesis

© 2019 Theo Broeders