Poppet Valve (IL)

A poppet valve in an isothermal fluid network.

blockType: EngeeFluids.IsothermalLiquid.Valves.FlowControl.Poppet

Path in the library:

/Physical Modeling/Fluids/Isothermal Liquid/Valves & Orifices/Flow Control Valves/Poppet Valve (IL)

Description

Block Poppet Valve (IL) It is a flow control valve in an isothermal fluid network. The plate can be cylindrical or spherical. The saddle may have sharp edges or be conical. The poppet valve opens or closes according to the displacement signal in port S. A positive signal means the plate is retracted and the valve is opened.

The diagram of the poppet valve is shown in the figure.

poppet valve il 1 en

poppet valve il 2 en

Opening area for cylindrical plate

The valve opening area is calculated as follows:

where

— the vertical distance between the outer edge of the cylindrical plate and the seat, as shown in the diagram above;
— parameter value Seat cone angle;
— parameter value Stem diameter;
— parameter value Leakage area.

The hole area is limited by the maximum displacement :

For any displacement of the rod exceeding , value is the sum of the maximum hole area and the parameter value Leakage area:

For any combination of the input value S and the displacement of the cylindrical plate, which is less than 0, the minimum valve area is Leakage area.

Opening area for the ball dish

Seat with sharp edges_

The valve opening area is calculated as follows:

where

— the vertical distance between the outer edge of the ball and the saddle;
— saddle radius, parameter value Seat orifice diameter;
— the radius of the ball Ball diameter;
— geometric parameter: ;
— parameter value Leakage area.

The hole area is limited by the maximum displacement :

For any ball displacement exceeding , value is the sum of the maximum hole area and the parameter value. Leakage area:

For any combination of the input value S and the ball displacement that is less than 0, the minimum valve area is Leakage area.

conical saddle

The valve opening area is calculated as follows:

where

— the vertical distance between the outer edge of the ball and the saddle;
— parameter value Seat cone angle;
— geometric parameter: where — the radius of the ball;
— parameter value Leakage area.

The hole area is limited by the maximum displacement :

For any ball displacement exceeding , value is the sum of the maximum hole area and the parameter value. Leakage area:

For any combination of the input value S and the ball displacement that is less than 0, the minimum valve area is Leakage area.

Numerical smoothing of the displacement

The block calculates the plate displacement as follows:

where

— input scalar on port S;
— parameter value Poppet position when in the seat;
— maximum offset.

If the parameter Smoothing factor if it is not equal to zero, then a smooth change in the offset value between 0 and .

The equation of conservation of mass

The equation of conservation of mass:

The mass flow through the valve is calculated as:

where

— flow coefficient, the value of the parameter Discharge coefficient;
— valve opening area;
— parameter value Cross-sectional area at ports A and B;
— the average density of the liquid;
— pressure difference in the valve .

Critical pressure drop, — pressure drop, determined from the value of the critical Reynolds number , set by the parameter Critical Reynolds number, which is the transition point of the regime between laminar and turbulent flow:

Pressure loss allows you to take into account the decrease in pressure in the valve due to a decrease in its area and is calculated as:

Pressure recovery describes a positive pressure change in the valve due to an increase in area. To ignore pressure recovery, uncheck the box. Pressure recovery. In this case, the pressure loss is .

Ports

Conserving

# A — Isothermal liquid port
Isothermal liquid

Details

A hole for the entry or exit of liquid.

Program usage name

port_a

# B — Isothermal liquid port
Isothermal liquid

Details

A hole for the entry or exit of liquid.

Program usage name

port_b

Input

# S — displacement of the rod, m
scalar

Details

The movement of the control element in m, specified as a scalar.

Data types	`Float64`
Complex numbers support	I don’t

Parameters

# Poppet geometry — type of plate shape
Cylindrical stem | Round ball

Details

The type of plate shape. You can choose either a cylindrical or a spherical control.

Values	`Cylindrical stem` \| `Round ball`
Default value	`Cylindrical stem`
Program usage name	`geometry`
Evaluatable	Yes

# Stem diameter — diameter of the cylindrical rod
m | cm | ft | in | km | mi | mm | um | yd

Details

The diameter of the cylindrical rod.

Dependencies

To use this parameter, set for the parameter Poppet geometry meaning Cylindrical stem.

Units	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`0.01 m`
Program usage name	`stem_diameter`
Evaluatable	Yes

# Seat cone angle — angle of opening of the conical seat
deg | rad | rev | mrad

Details

The opening angle of the conical seat.

Dependencies

To use this parameter, set for the parameter Poppet geometry meaning Cylindrical stem or set for the parameter Poppet geometry meaning Round ball, and for the parameter Valve seat specification meaning Conical.

Units	`deg` \| `rad` \| `rev` \| `mrad`
Default value	`120.0 deg`
Program usage name	`cone_angle`
Evaluatable	Yes

# Poppet position when in the seat — displacement of the control element
m | cm | ft | in | km | mi | mm | um | yd

Details

Plate displacement when the valve is closed. A positive value other than zero indicates that the valve is partially open. A negative value other than zero indicates a closed valve, which remains closed during the initial displacement specified by the scalar at the inlet S.

Units	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`0.0 m`
Program usage name	`min_control_displacement`
Evaluatable	Yes

# Leakage area — the gap area in the fully closed position
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

The sum of all clearances when the valve is in the fully closed position. Any area less than this value is equal to the specified leakage area. This parameter contributes to the stability of the numerical solution by maintaining the continuity of the flow.

Units	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`1.0e-10 m^2`
Program usage name	`leakage_area`
Evaluatable	Yes

# Cross-sectional area at ports A and B — the area at the inlet or outlet of the valve
m^2 | cm^2 | ft^2 | in^2 | km^2 | mi^2 | mm^2 | um^2 | yd^2

Details

The cross-sectional area at the input and output ports A and B. This area is used when calculating the mass flow through the valve.

Units	`m^2` \| `cm^2` \| `ft^2` \| `in^2` \| `km^2` \| `mi^2` \| `mm^2` \| `um^2` \| `yd^2`
Default value	`Inf m^2`
Program usage name	`port_area`
Evaluatable	Yes

# Discharge coefficient — expense ratio

Details

The correction factor is the ratio of the actual mass flow to the theoretical mass flow through the valve.

Default value	`0.64`
Program usage name	`C_d`
Evaluatable	Yes

# Critical Reynolds number — upper limit of the Reynolds number for laminar flow

Details

The upper limit of the Reynolds number for laminar flow through the valve.

Default value	`150.0`
Program usage name	`Re_critical`
Evaluatable	Yes

# Smoothing factor — numerical smoothing factor

Details

The continuous smoothing coefficient, which ensures smooth opening by correcting the valve characteristics in the almost open and almost closed positions. Set a non-zero value less than one to increase the stability of the simulation in these modes.

Default value	`0.01`
Program usage name	`smoothing_factor`
Evaluatable	Yes

# Pressure recovery — accounting for increased pressure during expansion of the area

Details

Determines whether an increase in pressure will be taken into account when liquid flows from an area with a smaller cross-sectional area to an area with a larger cross-sectional area.

Default value	`false (switched off)`
Program usage name	`pressure_recovery`
Evaluatable	Yes

# Valve seat specification — geometry of the valve seat
Sharp-edged | Conical

Details

Geometry of the valve seat. The unit uses this parameter to calculate the open area between the plate and the saddle.

Dependencies

To use this parameter, set for the parameter Poppet geometry meaning Round ball.

Values	`Sharp-edged` \| `Conical`
Default value	`Sharp-edged`
Program usage name	`seat_type`
Evaluatable	Yes

# Ball diameter — diameter of the ball control
m | cm | ft | in | km | mi | mm | um | yd

Details

Diameter of the ball control.

Dependencies

To use this parameter, set for the parameter Poppet geometry meaning Round ball.

Units	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`0.01 m`
Program usage name	`ball_diameter`
Evaluatable	Yes

# Seat orifice diameter — seat diameter
m | cm | ft | in | km | mi | mm | um | yd

Details

The diameter of the saddle.

Dependencies

To use this parameter, set for the parameter Poppet geometry meaning Cylindrical stem.

Units	`m` \| `cm` \| `ft` \| `in` \| `km` \| `mi` \| `mm` \| `um` \| `yd`
Default value	`0.007 m`
Program usage name	`orifice_diameter`
Evaluatable	Yes