Solenoid (P)#

The Solenoid (P) block simulates the operation of the corresponding element in a pneumatic network, which operates according to the following principle:

In addition to two standard pneumatic ports (input and output), the unit has a control port via an automatic signal that takes values in the range [0;1]. If the signal is greater than or equal to 0.5, the valve (solenoid) gradually opens; otherwise, it closes. The current position, and thus the flow cross-sectional area, depends on the block properties defined by the user:

Valve initial position can be Open and Closed and describes the state of the valve prior to calculation;
Open valve time ($t_{Open}$) and Close valve time ($t_{Close}$) determine the rate of change of its position when moving in one direction or another;
Max valve area reflects the maximum solenoid capacity when fully open.

Note

The nature of opening and closing the valve is linear, that is, the speed of movement of the control element does not depend on the time and current position.

Calculation of valve cross-sectional area:

When it is opened, the valve cross-sectional area $A_{valve}$ is defined as (1) :

(1)#\[A_{valve}=A_{init}+time/t_{Open}\cdot (A_{max}-A_{leak})\]

When it is closed, the valve cross-sectional area $A_{valve}$ is defined as (2) :

(2)#\[A_{valve}=A_{init}-time/t_{Close}\cdot (A_{max}-A_{leak})\]

where:

$A_{init}$ is the initial valve area, [м$^2$], which, at the start of calculation from the zero moment of the model time, takes the value determined by Valve initial position property - either $A_{max}$ (he valve is completely open), or 0 (the valve is completely closed). In case of shutdown and subsequent continuation of the calculation, $A_{init}$ takes the last calculated value;

$t_{Open}$ – valve opening time, [s];

$t_{Close}$ – valve closing time, [s];

$A_{max}$ – maximum valve area, [m$^2];

$A_{leak}$ – leakage area, [m$^2$].

Law of mass conservation (3) :

(3)#\[m_1+m_2=0\]

where $m_1$ and $m_2$ is flow rate at block input and output, [kg/s].

Law of conservation of energy (4) :

(4)#\[\phi_A+\phi_B=0\]

where:

$\phi_A$ - energy flow at the input, [W];

$\phi_B$ - energy flow at the output, [W].

1. Properties#

Property	Default Value	Description	Units of measurement
Valve initial position: Closed; Open	Closed	-	-
Open valve time	0.05	-	s
Close valve time	0.1	-	s
Max valve area	1.0E-4	-	m$^2$
Площадь утечки при закрытом клапане	1.0E-10	-	m$^2$
Leakage area	0.09	-	m$^2$
Discharge coefficient, available when selecting `Pressure recovery` - `On`	0.64	-	-
Laminar flow pressure ratio	0.999	-	-
Pressure recovery: On; Off	On	-	-

2. Inputs and outputs#

Parameters	Input/Output	Description	Units of measurement	Port type
Input	Input	-	-	Pneumatics
Signal [0;1]	Input	-	-	Automation
Output	Output	-	-	Pneumatics

In order to see the connection capabilities of the block, you need to go to page Description of block ports