### 7.4.1. Morphology

Morphology is used to describe the connectivity or distribution of the fluid - whether it forms a single continuous medium, or whether it is present, for example, in small droplets that are not connected.

You can select from:

- Continuous Fluid
- Dispersed Fluid
- Dispersed Solid
- Particle Transport Fluid
- Particle Transport Solid
- Polydispersed Fluid
- Droplets (Phase Change)

#### 7.4.1.1. Continuous Fluid

A continuous phase or continuous fluid is one which forms a continuous connected region. An example is air, when modeling rain drops in air.

#### 7.4.1.2. Dispersed Fluid

A dispersed fluid is a fluid that is present in discrete regions that are not connected. Examples are water droplets in air or gas bubbles in a liquid.

#### 7.4.1.3. Dispersed Solid

A dispersed solid is one that is present in discrete regions that are not connected, for example, solid particulates.

You must select the morphology of all fluids as continuous if you want to use the `Mixture` model on the Multiphase Options tab. If dispersed fluids or solids are included, then the `Particle` model will be the only valid option.

Examples of multiphase flow with different morphologies are available. For details, see Multiphase Examples.

#### 7.4.1.4. Particle Transport Fluid

This is used for fluids when using the Particle Transport Model. For details, see Particle Morphology Options.

#### 7.4.1.5. Particle Transport Solid

This is used for solids when using the Particle Transport Model. For details, see Particle Morphology Options.

#### 7.4.1.6. Polydispersed Fluid

A polydispersed fluid is a fluid that is present in discrete regions that are not connected and with varying sizes of the discrete regions. Typically, this morphology is used for modeling air bubbles of varying sizes in a liquid.

#### 7.4.1.7. Droplets (Phase Change)

Droplets (Phase Change) are required if you want to use the Droplet Condensation Model. For details, see Droplet Condensation Model.

Release 18.2 - © ANSYS, Inc. All rights reserved.