Encyclopaedia Index

### TITLE : Longitudinal vortex generators

BY : Dr S V Zhubrin, CHAM Ltd

DATE : November, 2000

FOR : Demonstration case for V3.3.1

### INTRODUCTION

The longitudinal vortices are effective for boundary layer control because they prevent separation by bringing fluid of high momentum into the boundary layer. Longitudinal Vortex Generators, LVG, also increase the heat transfer by transporting fluid from the wall into the core flow and vice versa.

A "cut-off" technique, PARSOL, is used here to represent the irregular shapes of LVG on the cartesian grid. The case is aimed at the demonstration of the PARSOL method for the simulation of the hydrodynamic performance of Rectangular Wing Pair,RWP, and Delta Winglet Pair, DWP, attached to a channel wall of the rectangular duct in a turbulent air flow.

### PHYSICAL SITUATION

The demonstration case considered consists of a channnel with a built-in array of two LVGs in the form of RWP and DWP. The air flow is supposed to be fully turbulent and incompressible.

The vortex generators are positioned about a half of channel length behinf the entrance. The spacing between generators is about half of channel width. The wing span is equal to 75 percent of the channel height.

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

### Conservation equations

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 RESULTS

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

Pictures are as follows :

### THE IMPLEMENTATION

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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