Numerical Results

Turbulent flow of circular straight pipe with roughness element along streamwise

In the case of eight roughness elements (Tube No.1,Re=26550)

Note:Figures are shown on one-eighth of total cross section, considering symmetrical flow.

Numerical object

Computational mesh

Streamwisr velocity

Path lines

Turbulence energy

Streamwise normal velocity

Radial normal stress

Peripheral normal stress

Shear stress between streamwise and radial direction

Shear stress between streamwise and peripheral direction

Shear stress between radial and peripheral direction

Development of secondary flow (Animation)

In the case of eight roughness elements (Tube No.1,Re=4950)

Note:Figures are shown on one-eighth of total cross section, considering symmetrical flow.

Numerical object

Computational mesh

Streamwise velocity

Path lines

Turbulence energy

Streamwisr normal stress

Radial normal stress

Peripheral normal stress

Shear stress between streamwise and radial direction

Shear stress between streamwise and peripheral direction

Shear stress between radial and peripheral direction

Development of secondary flow (Animation)

In the case of eight roughness elements with low height (Tube No.2)

Note:Figures are shown on one-eighth of total cross section, considering symmetrical flow.

Numerical object

Computational mesh

Streamwisr velocity

Path lines

Turbulence energy

Streamwise normal stress

Radial normal stress

Peripheral normal stress

Shear stress between streamwise and radial direction

Shear stress between streamwise and peripheral direction

Shear stress between radial and peripheral direction

Development of secondary flow (Animation)

In the case of sixteen roughness elements with low height (Tube No.3)

Note:Figures are shown on one-sixteenth of total cross section, considering symmetrical flow.

Numerical object

Computational mesh

Streamwise velocity

Path lines

Turbulence energy

Streamwisr normal stress

Radical normal stress

Peripheral normal stress

Shear stress between streamwise and radial direction

Shear stress between streamwise and peripheral direction

Shear stress between radial and peripheral direction

Development of secondary flow (Animation)

This research work has been done in coorperation with Mr. Shinohara.
He had graduated from Utsunomiya University at 1998.
He has belonged to HITACHI CO.