This study investigates heat and fluid flow within a narrowing channel with a smooth transition using ANSYS FLUENT simulation software. The simulation models a 2D, steady, turbulent flow using the SST turbulence model. The geometry was created in Microsoft Excel and meshed in ANSYS containing over 41,000 elements. Boundary conditions were applied to model the flow through the narrowing channel and obtain velocity, pressure, and turbulence parameter solutions to analyze the entrance length effect in terms of millimeters and centimeters.

1. Introduction
In this study, the effects of flow and heat transfer (future works) within the narrowing
channel with soft transition were investigated. The flow is steady, two-dimensional and
turbulent flow, and SST turbulence model is used. Finite volume method ANSYS FLUENT
software was used for modelling and solution process.
This tutorial shows how to do the following:
• using the mixture model with cavitation effects on transitions places
• showing entrance length effect of geometry (units’ mm and cm)
Expansion and sudden narrow channels are known as transition pipes in engineering
applications. It is used in many flow systems in practice such as in water and air tunnels, in the
inlets and outlets of flow machines, in the air inlet ducts of airplanes, in the ventilation systems
of air conditioners and mines.
Problem Description
It is to obtain velocity, pressure solutions of the smooth transition flow in the narrowing
channel using ANSYS FLUENT 19.2 Academic Student version and to present the solutions
of the turbulence parameters of the analysis.
Figure 1 Problem Schematic
The project geometry is shown in Figure 1. Two-dimensional geometry model was created
using Microsoft Excel. Dimensions are given in cm.
Meshing

2. Figure 2 Elements (41589) and Nodes (42750)
Figure 3 Elements (41589) and Nodes (42750) (zoomed)
Solver Settings

3. Models
Materials

4. Phases

5. Boundary Conditions

6. Operating Conditions
Solution

7. Velocity and pressure distributions

8. ,

9. Entrance Length Effect
in terms of mm;
in terms of cm;