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In this tutorial, you will learn to:

• Initialize the case using Load a field functionflow field initial condition from a file using User Defined Function (UDF).
• Use Discrete Phase Model (DPM) to simulate particles in a flow.
• Define particle injection using an injection file / Create injection files using MATLAB codes.
• Visualize particle flow in CFD-Post.

Problem Specification

Consider a jet in a 1m * 1m region below.  There are 400 particles randomly distributed in the region with random initial position as well as velocity direction and magnitude, as shown below. 
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In this tutorial, we study a case of particle laden flows. The purpose is to illustrate some of the complex interactions between the uid phase and a dispersed particle phase using commercially available tools. For this purpose, we study a 2D-periodic double shear layer with disceminated particles as shown bellow:
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In the absence of any perturbation, a mixing layer, for instance a Ux = U tanh(y) profile, diffuses under the action of viscosity to the mean value of top and bottom velocities. On the other hand, specially manufactured oscillations in the shearing layers will lead to the evolution of vorticies. These perturbations must satisfy the Orr-Sommerfeld equation, otherwise they are suppressed by viscosity. In this tutorial we provide the initial flow condition containing the Orr-Sommerfeld perturbation in a separate input file.

The point of having vorticies develop in the flow field, is to observe the interaction of particles with these structres. In a general sens, "light" particles get trapped in ow vorticies, while "heavier" particles carrying more inertia might get expelled under a corriolis-type effect from the swirling regions to gather along stretching regions of the ow. This effect is known as preferential concentration and is illustrated in the following sketch:
[Insert preferential concentration sketch]
Formal denitions, and a thorough discussion is provided in the Pre-Analysis section.As the particles are affected by the jet, they will have a tendency to travel along in the direction of the fluid flow. However, this property is governed by a non-dimensionalized parameter, the Stokes number. By simulating the movement of particles of different stokes number in a jet flow, the effects of the Stokes number on discrete particles in a fluid flow can be better studied and understood. 

Go to Step 1: Pre-Analysis & Start-Up

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