azplugins.flow

Overview

FlowField	Base flow field.
ConstantFlow	Constant flow profile.
ParabolicFlow	Parabolic flow profile between parallel plates.

Details

Flow fields.

class hoomd.azplugins.flow.ConstantFlow(velocity)

Bases: FlowField

Constant flow profile.

Parameters:

velocity (tuple) – Flow field.

This flow corresponds to a constant vector field, e.g., a constant backflow in bulk or a plug flow in a channel. The flow field is independent of the position it is evaluated at.

Example:

u = hoomd.azplugins.flow.ConstantFlow(velocity=(1, 0, 0))

class hoomd.azplugins.flow.FlowField

Bases: _HOOMDBaseObject

Base flow field.

class hoomd.azplugins.flow.ParabolicFlow(mean_velocity, separation)

Bases: FlowField

Parabolic flow profile between parallel plates.

Parameters:

• mean_velocity (float) – Mean velocity.

• separation (float) – Separation between parallel plates defining the flow field.

This flow field generates the parabolic flow profile in a slit geomtry:

\[u_x(y) = \frac{3}{2}U \left[1 - \left(\frac{y}{H}\right)^2 \right]\]

The flow is along x with the gradient in y. The separation between the two plates is \(2H\), and the channel is centered around \(y=0\). The mean_velocity is \(U\).

Example:

u = hoomd.azplugins.flow.ParabolicFlow(
    mean_velocity=2.0, separation=0.5
)

Note

Creating a flow profile does not imply anything about the simulation box boundaries. It is the responsibility of the user to construct appropriate bounding walls commensurate with the flow profile geometry.