Numerical analysis of turbulent structure through a circular-to-rectangular transition duct
Numerical analysis is used to investigate three dimensional turbulent structure and fluid flow behavior in a circular-to-rectangular transition duct. The CR transition duct configuration for the present calculation has been shown. In the calculation, an algebraic Reynolds stress model together with a boundary-fitted coordinate system is applied to a circular-to-rectangular duct in order to solve anisotropic turbulent flow precisely. The calculated results are compared with the experimental results to examine the validity of the present method. The compared quantities include the streamwise mean-velocity, transverse mean velocity vectors, mean longitudinal vorticity and components of the Reynolds stress tensor. For example, the comparison of streamwise velocity at X{sub 1}/R = 4.0, where in the midregion of transition, is displayed. The generation of the low velocity observed near the side wall is indicative of the longitudinal vortex pair that is formed as a result of the secondary motion. In comparison with the experimental results, it is found that the present method well predicts a secondary flow pattern which develops into a discrete vortex pair along the duct sidewalls. The vortex pair significantly distorts both the mean flow and turbulence field. As for the comparison of several Reynolds stress components, although the agreement is not perfect in detail, main features are reproduced by the present method. These calculated results suggest that an algebraic Reynolds stress model is useful for this complicated turbulent flow.
- Research Organization:
- Utsunomiya Univ., Youtou (JP)
- OSTI ID:
- 20030498
- Resource Relation:
- Conference: 5th ASME/JSME Thermal Engineering Joint Conference, San Diego, CA (US), 03/14/1999--03/19/1999; Other Information: 1 CD-ROM. Operating system required: Windows i386(tm), i486(tm), Pentium (R) or Pentium Pro, MS Windows 3.1, 95, or NT 3.51, 8 MB RAM, MacIntosh and Power MacIntosh with a 68020 or greater processor, System software version 7.1, 3.5 MB RAM (5 MB for PowerMac) 6 MB available hard-disk space, Unix; PBD: 1999; Related Information: In: Proceedings of the 5th ASME/JSME thermal engineering joint conference, [3600] pages.
- Country of Publication:
- United States
- Language:
- English
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