Nuclear Energy for New Europe 2009

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No: 822

Conference: Nuclear Energy for New Europe 2009

Title: A numerical investigation on a submerged, axis-symmetric jet impingement

Theme: Nuclear Fusion

Author(s): Martin Draksler, Boštjan Končar

Contact : Martin Draksler

E-mail: draksler.martin@gmail.com

Address: Institut "Jožef Stefan" R4
1001 Ljubljana

Country: Slovenia

Jet impingement technique is characterized by a high heat removal capability and therefore it has been proposed as a cooling method for a new helium cooled divertor, a high-heat flux component of the future fusion reactor called DEMO. Since power plant efficiency depends on the divertor´s heat removal capability it has to consider some demands; i.e. high heat transfer and low pressure drop.
The objective of this study is to investigate the effect of the nozzle inlet geometry on heat removal capability and pressure drop. Two different nozzle geometry parameters were tested; chamfer angle _ and chamfer depth Lch. The numerical results are validated against the experiment [1]. Numerical model used for geometry study was preliminary validated on free jet impingement experiment [2].
The numerical study was performed with the CFD code ANSYS-CFX-11 [3], using RANS approach and eddy-viscosity type SST turbulence model. Since numerical results are highly affected by the turbulence model the effect of the Kato-Launder turbulent production limiter [4] was analyzed.

[1] L. A. Brignoni and S. V. Garimella. Effects of nozzle-inlet chamfering on pressure drop
and heat transfer in confined air jet impingement. Int. J. of Heat and Mass Transfer, 43,
2000.
[2] J. W. Baughn and S. Shimizu. Heat transfer measurements from a surface with uniform
heat flux and an impinging jet. J. Heat Transfer, 111:1096–1098, 1989.
[3] ANSYS. CFX-11 Documentation, 2007.
[4] M. Kato and B. E. Launder. The modeling of turbulent flow around stationary and vibrating
square cylinders. 1993.

No:	822
Conference:	Nuclear Energy for New Europe 2009
Title:	A numerical investigation on a submerged, axis-symmetric jet impingement
Theme:	Nuclear Fusion
Author(s):	Martin Draksler, Boštjan Končar
Contact :	Martin Draksler
E-mail:	draksler.martin@gmail.com
Address:	Institut "Jožef Stefan" R4 1001 Ljubljana
Country:	Slovenia

Jet impingement technique is characterized by a high heat removal capability and therefore it has been proposed as a cooling method for a new helium cooled divertor, a high-heat flux component of the future fusion reactor called DEMO. Since power plant efficiency depends on the divertor´s heat removal capability it has to consider some demands; i.e. high heat transfer and low pressure drop. The objective of this study is to investigate the effect of the nozzle inlet geometry on heat removal capability and pressure drop. Two different nozzle geometry parameters were tested; chamfer angle _ and chamfer depth Lch. The numerical results are validated against the experiment [1]. Numerical model used for geometry study was preliminary validated on free jet impingement experiment [2]. The numerical study was performed with the CFD code ANSYS-CFX-11 [3], using RANS approach and eddy-viscosity type SST turbulence model. Since numerical results are highly affected by the turbulence model the effect of the Kato-Launder turbulent production limiter [4] was analyzed. [1] L. A. Brignoni and S. V. Garimella. Effects of nozzle-inlet chamfering on pressure drop and heat transfer in confined air jet impingement. Int. J. of Heat and Mass Transfer, 43, 2000. [2] J. W. Baughn and S. Shimizu. Heat transfer measurements from a surface with uniform heat flux and an impinging jet. J. Heat Transfer, 111:1096–1098, 1989. [3] ANSYS. CFX-11 Documentation, 2007. [4] M. Kato and B. E. Launder. The modeling of turbulent flow around stationary and vibrating square cylinders. 1993.