Boundary Values Reference

Depending on how the Lagrangian phase boundary conditions and models are set, you can control the interaction with boundaries using the following values:

Ahlert
Diameter Ratio
DNV
Erosion Ratio
Minimum Splashed Diameter
Neilson-Gilchrist
Normal Restitution Coefficient
Number Splashed
Oka
Splashing Angle
Tangential Restitution Coefficient
Velocity Ratio

Ahlert

This sub-node is added to the Erosion Ratio node when Ahlert is chosen as the erosion ratio method. It represents the Ahlert Correlation. The default values for this method are for liquid-borne semi-rounded sand particles eroding aluminum, as given by McLaury et al. [674].

Ahlert Properties

Material Coefficient: A material-dependent constant. It is the quantity $K$ in Eqn. (3308).
Shape Coefficient: A factor to account for the shape of the particles. It is the quantity $F_{s}$ in Eqn. (3308). Suggested values are 1 for angular particles, 0.53 for semi-rounded particles and 0.2 for fully rounded particles.
Transition Angle: The angle $α_{0}$ which is the upper limit of validity of the Low Alpha Function and the lower limit of validity of Eqn. (3309).
Low Alpha Function: The polynomial for the angle function $f (α)$ in Eqn. (3308) to be used below the transition angle $α_{0}$ . The polynomial is in terms of the incidence angle in radians.
Coefficient W, X, Y, Z: The coefficient $w$ , $x$ , $y$ , or $z$ in Eqn. (3309) for the angle function $f (α)$ above the transition angle $α_{0}$ . Coefficient Z is read-only.
Reference Velocity: The normalization factor for the particle velocity. It is the quantity $u_{r e f}$ in Eqn. (3308).
Velocity Exponent: The exponent for the normalized velocity. It is the quantity $n$ in Eqn. (3308).

Diameter Ratio

Added to the tree when Splash is chosen as the interaction mode at a boundary. The ratio of splashed particle diameter to the diameter of the impinging particle. If the Rosin-Rammler exponent is zero or negative, all splashed particles are given the same diameter. If the exponent is positive, particle diameter is set according to the Rosin-Rammler distribution and the diameter ratio defines the ratio of characteristic size $D_{r e f}$ to the diameter of the impinging particle.

DNV

This sub-node is added to the Erosion Ratio node when DNV is chosen as the erosion ratio method. It represents the DNV Correlation. The default values for this method are for air-borne sand eroding carbon steel, and are taken from Haugen et al. [663].

DNV Properties

Material Coefficient: A material-dependent constant. It is the quantity $K$ in Eqn. (3310). The default value is 2.0E-9.
Reference Velocity: The normalization factor for the particle velocity. It is the quantity $u_{r e f}$ in Eqn. (3310). The default value is 1.0 m/s.
Velocity Exponent: The exponent for the normalized velocity. It is the quantity $n$ in Eqn. (3310). The default value is 2.6.
Angle Function: The polynomial for the angle function $f (θ)$ in Eqn. (3310). It is evaluated in terms of the incidence angle in degrees. See Eqn. (3311).

Erosion Ratio

Added to the tree when the Erosion model is activated in the Lagrangian phase. Depending on the method that is chosen for the erosion ratio, a sub-node is added to this node.

Erosion Ratio Properties

Method

Selects the method for calculating the erosion ratio.

Ahlert: Specifies that the erosion ratio is calculated using the Ahlert Correlation. An Ahlert node is added as a child to this node.
Field Function: Specifies that the erosion ratio is calculated using a field function. This method is typically user-defined and can involve only constants and particle-based functions. A field function method node is added as a child to this node.
DNV: Specifies that the erosion ratio is calculated using the DNV Correlation. A DNV node is added as a child to this node.
Neilson-Gilchrist: Specifies that the erosion ratio is calculated using the Neilson-Gilchrist Correlation. A Neilson-Gilchrist node is added as a child to this node.
Oka: Specifies that the erosion ratio is calculated using the Oka Correlation. An Oka node is added as a child to this node.

Dimensions

The dimensionality of the erosion ratio (read-only).

Minimum Splashed Diameter

Added to the tree when Splash is chosen as the interaction mode at a boundary. The minimum allowed size of an impinging droplet. Smaller droplets do not splash; instead, they rebound.

Neilson-Gilchrist

This sub-node is added to the Erosion Ratio node when Neilson-Gilchrist is chosen as the erosion ratio method. It represents the Neilson-Gilchrist Correlation. The default values for this method are for liquid-borne sand eroding AISI 4130 steel, and are taken from Wallace et al. [713].

Neilson-Gilchrist Properties

Transition Angle: The angle at which cutting deformation changes behavior. It is the quantity $α_{0}$ in Eqn. (3313).
Deformation Cutoff Velocity: The normal velocity at which deformation wear is minimized. It is the quantity $K$ in Eqn. (3314).
Cutting Coefficient: The material-dependent constant governing cutting erosion. It is the quantity $ε_{C}$ in Eqn. (3313).
Deformation Coefficient: The material-dependent constant governing deformation erosion. It is the quantity $ε_{D}$ in Eqn. (3314).

Normal Restitution Coefficient

Added to the tree when Rebound is chosen as the interaction mode at a boundary. This coefficient is the constant of proportionality $e_{n}$ for the normal components of rebounding and impinging velocities. See Rebound.

Number Splashed

Added to the tree when Splash is chosen as the interaction mode at a boundary. The number of parcels that replace a single impinging parcel in a splash event.

Oka

This sub-node is added to the Erosion Ratio node when Oka is chosen as the erosion ratio method. It represents the Oka Correlation. The default values for this method are for air-borne sand eroding 0.025% carbon steel, and are taken from Oka et al. [681] and Oka and Yoshida [682], except for the Reference Erosion Ratio, which is derived from the DNV Correlation.

Oka Properties

Reference Velocity: The normalization factor for the particle velocity. It is the quantity $u_{r e f}$ in Eqn. (3315).
Velocity Exponent: The exponent for the normalized velocity. It is the quantity $k_{2}$ in Eqn. (3315).
Reference Erosion Ratio: The erosion ratio at reference conditions and normal incidence. It is the quantity $e_{90}$ in Eqn. (3315).
Coefficient Hv: The coefficient $H_{v}$ in the angle function Eqn. (3316). It is typically, but not necessarily, equal to the Vickers hardness of the eroded material in GPa.
Coefficient n1: The coefficient $n_{1}$ in the angle function Eqn. (3316).
Coefficient n2: The coefficient $n_{2}$ in the angle function Eqn. (3316).
Reference Diameter: The normalization factor for the particle diameter. It is the quantity $D_{r e f}$ in Eqn. (3315).
Diameter Exponent: The exponent for the normalized diameter. It is the quantity $k_{3}$ in Eqn. (3315).

Rosin-Rammler Exponent

Added to the tree when Splash is chosen as the interaction mode at a boundary. The exponent in the Rosin-Rammler distribution, $k$ in Eqn. (2299). If the exponent is positive non-zero value, the Rosin-Rammler distribution is used with the reference diameter $D_{ref}$ . In other cases ( $k \leq 0$ ), the constant diameter is applied. The default 0.

Splashing Angle

Added to the tree when Splash is chosen as the interaction mode at a boundary. Together with the Tangential Velocity Ratio, this angle defines the direction of the velocity of splashed particles. For more information, see Splash in the Theory section.

Tangential Restitution Coefficient

Added to the tree when Rebound is chosen as the interaction mode at a boundary. This coefficient is the constant of proportionality $e_{t}$ for the tangential components of rebounding and impinging velocities. See Rebound.

Tangential Velocity Ratio

Added to the tree when Splash is chosen as the interaction mode at a boundary. The ratio of additional splashed droplet tangential velocity magnitude to parent droplet tangential velocity magnitude. A non-negative value, set by profile. The default is 0. For more information, see Splash in the Theory section.

Velocity Ratio

Added to the tree when Splash is chosen as the interaction mode at a boundary. The ratio of the magnitude of the velocity of splashed droplets to the magnitude of the impinging velocity.