 DPM Injection and Particle Types (Injection Type, Injection Conditions & Injection Initial Conditions )

Discrete Phase Model

In numerical and theoretical studies of multiphase flows, you can writhe the governing equations of the flow separately for each phase. Two approaches can be used to study the motion of each phase. The first approach is Eulerian-Eulerian methods, in which the governing equations of each of the continuous and discrete phases must be written based on the Eulerian view. However, in the Eulerian-Lagrangian approach, continuous phase equations are applied from Eulerian’s point of view, while discrete phase equations are written and used using Lagrangian laws.

DPM Injection Type

Ansys fluent software has provided different types of injections that we can use according to the type of injection and are as follows:

Single, group, Cone, surface, file, volume, plain orifice atomizer, pressure swirl atomizer, air blast atomizer, flat fan atomizer, effervescent atomizer

What are the “Injection” conditions in Fluent?

Injection Time

For Transient problems and to detect unsteady particle tracking, the injection start time and stop time should be specified in the point properties section. If we set the value to zero for the start and end of the injection, they are injected only at the moment of starting.

Discharge Coefficient

In a nozzle, the discharge coefficient is equal to the ratio of actual discharge to ideal discharge, and you can express its mathematical relation as follows: • Where C_d is the discharge coefficient
• m ̇mass flow rate
• fluid density
• Volumetric volume
• A cross-section
• u fluid velocity
• And ∆p is the pressure drop.

Injection Velocity

Adjust the particle velocity flows along the spray cone angle specified in the “Velocity” section.

DPM Injection Initial Conditions

For the injection to take place, you must define the injection properties. The injection properties are:

• Location

We need to specify the injection site to inject from that area.

• Velocity

By specifying this parameter, you can determine the direction and speed of particle injection.

• Temperature

Specifies the particle temperature.

• Start time & Stop time

The injection starts and stops time must be specified in the point properties section to detect unsteady particles.

• Drop size distribution

We can determine how the droplet size distribution works.

• Flow rate

We also need to determine the mass flow rate of the particles.

The initial injection conditions are essential for spray simulation. The internal flow of the injector has strong effects on the external spray. Call On WhatsApp