BY : Dr S V Zhubrin, CHAM Ltd

DATE : November, 2000

FOR : Demonstration case for V3.3.1

Longitudinal vortices generated by Delta Winglet Pairs, DWP, at the angles of attack spiral the flow around the main flow direction and thereby increase mixing and heat transfer. A "cut-off" technique, PARSOL, for the representation of the complex shapes on the cartesian grid is used here aimed at the demonstration of the method for the simulation of turbulent 3D flow over a cylinder with attached DWP.

The demonstration case considered consists of a half of cylinder placed in an air flow within a rectangular duct. The delta-winglet is mounted on the wall behind a cylinder. The position of the wingle tip is a half of cylinder diameter relative to the center of cylinder. The right triangle winglet with a hight equal to the duct width has an angle of attack of 45 degree.

The pressure difference between the pressure and the suction sides of the winglet is anticipated to generate longitudinal vortex which supresses the flow separation on cylinder and develops well pronounced secondary flow.

The task is to calculate the flow and pressure fields along with all related field distributions.

The independent variables of the problem are the three components of cartesian coordinate system, namely X, Y and Z.

The main dependent (solved for) variables are:

- Pressure, P1
- Three components of velocity, U1, V1, W1
- Turbulence energy and its dissipation rate, KE, EP

The plots show the distribution of velocities, pressure and other related fields within the flow.

Pictures are as follows :

- Geometry considered
- Streamlines showing the vortex
- Secondary flow just behind cylinder
- Secondary flow further downstream
- Velocities at the bottom plane
- Velocities at a higher plane
- Velocities at 0.8H plane
- Pressure distributions
- Turbulent viscosity distributions
- Turbulence energy distributions
- Turbulence length scale distributions

All model settings have been made in VR-Editor of PHOENICS 3.3.1

The relevant Q1 file can be inspectedby clicking here.

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