Temperature Mixer Evaluation


Watch a Flow Path Visualization

Introduction

This case study presents the use of Azore as an engineering design evaluation tool. The geometry and flow path is shown in the animated image at the top of this page. This is a merging duct system where a hot gas stream is introduced through tubes into a cold gas stream in a larger primary duct. The typical question for this situation is what will be the temperature distribution downstream of the hot/cold merge point. Most likely the temperature distribution will be fairly stratified and depending on the application may be unacceptably stratified. If there are temperature stratification requirements then a flow mixing device must be designed to achieve the proper mixing.

Case Set up

Azore is a suitable tool for evaluating mixer designs for this situation. For discussion purposes two mixing situations have been simulated using Azore. The first situation characterizes the temperature distribution in the duct system when no mixing device is used. The second simulation evaluates a potential mixer design.

Results

There are many different design criteria that can be used to evaluate temperature mixing. One might be simply looking at the relative gas minimum/maximum temperature. Another might be to evaluate the variation from the mean temperature. Yet another might be to evaluate the temperature distribution visually by looking at simulation results. Any one of these methods has merit and can be used as a way for evaluating and comparing different temperature mixer designs.

For this case a visual account of the two simulations is presented in the image below. The gas temperature is shown at a number of planes down stream of the merge point. Notice that when the temperature mixer is introduced the hot gases are distributed across the primary gas stream rather than remaining along one side of the duct.