Flow Block

Represents the rate of change of a Stock. Controls the volume of entities moving into or out of a stock per unit of time.

Description

The Flow block represents the rate of change of a Stock. It controls how much quantity moves through the system per unit of time. It can represent birth rates, evaporation, cash flow, or any other rate of change.

Mathematical Model

Flow = Rate * Multiplier

The Flow block essentially defines the derivative of a connected Stock:

$$\frac{d(Stock)}{dt} = Flow$$

In this implementation, the block allows for a scaling multiplier: $$Output = Input \times Multiplier$$

Parameters

multiplier

A scaling factor applied to the input rate. Useful for converting units or applying a global gain to a specific flow.

• Default: 1
• Tooltip: A scaling factor applied to the input rate

Ports

rate (Input)

The base rate of the flow. Can be a constant value or calculated based on other system variables.

flow (Output)

The resulting flow rate, usually connected to the flow_in port of a Stock block.

See Also

• Stock: The primary destination or source for a Flow.
• Converter: Used to calculate rates based on stocks and other variables.
• Gain: Similar functionality but for general signal processing.