### 6.4.2. Model of Tabakoff and Grant

In the erosion model of Tabakoff and Grant, the erosion rate is determined from the following relation:

| (6–93)

where:

| (6–94)

| (6–95)

| (6–96)

| (6–97)

Here is the dimensionless mass (mass of eroded wall material divided by the mass of particle). is the particle impact velocity. is the impact angle in radians between the approaching particle track and the wall, being the angle of maximum erosion. to , and are model constants and depend on the particle/wall material combination.

#### 6.4.2.1. Implementation in CFX

The model constants in the original formulation of Tabakoff and Grant are only valid for particle velocities specified in feet per second [ft/s]. The Tabakoff formulation is modified in CFX as outlined below:

| (6–98)

where:

| (6–99)

| (6–100)

| (6–101)

| (6–102)

Note: The Tabakoff model typically returns an erosive wear with the dimensions milligrams of eroded material per gram of colliding particles. In CFX, this variable is converted into grams of eroded material per gram of colliding particles.

##### 6.4.2.1.1. Mapping of CFX to Original Tabakoff Constants

To make the model more general, the model is rewritten so that all model constants have a dimension of velocity. The following list shows the link between the constants of the original model and those in CFX:

##### 6.4.2.1.2. Constants

Value | Dimensions | CFX-Pre Variable
--- | --- | ---
| (dimensionless) | K12 Constant
| (dimensionless) |
| [Velocity] | Reference Velocity 1
| [Velocity] | Reference Velocity 2
| [Velocity] | Reference Velocity 3
| [deg] | Angle of Maximum Erosion

where:

| (6–103)

| (6–104)

| (6–105)

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