Cylindrical Poppet with Conical Seat (IL)

If the check box Moving body removed, and the movement of the body is not simulated, then the lifting of the cylindrical valve is defined as:

where

If the check box is Moving body If the valve body is installed, and the body movement is simulated, then the lift of the cylindrical valve is defined as:

where — moving the case in port CA.

The minimum flow area is determined by the curved surface of the truncated cone. It is assumed that this surface divides the area occupied by the liquid into two areas with different pressures. There is pressure on one of these areas. , and on the other — pressure . This assumption is reasonable if the valve lift is small compared to the seat diameter. If the rise is large, it is obvious that at some point the smallest limitation will be the area of the neck.

The area of the hole is calculated as:

Hydraulic diameter calculated as:

The active diameter is equal to the diameter of the valve plate .

For large values of elevation, the area , calculated using the formula above, will exceed the diameter of the neck. Square is equal to the area of the neck at the lift value :

The value used for , limited between (parameter value Lift corresponding to minimum area) and the smaller of the values (parameter value Lift corresponding to maximum area) and .

Usually it is zero, but it can be set higher to simulate the leakage rate. Meaning usually very large (for example, inf), but a much lower value can be set to simulate an additional hole.

Area value limited by the area of the hole:

Liquid volume , the pressure in which is equal to the pressure , additional to the volume when the valve is closed, is calculated as:

The derivative of the additional volume by calculated as:

If the check box Moving body removed, the volumes of liquid that are discharged to ports A and B are calculated as:

where and — parameter values Volume at port A corresponding to zero lift and Volume at port B corresponding to zero lift, respectively.

If the check box is Moving body installed:

Flow coefficient calculated as:

where

The average density is calculated at an average pressure .

Expense ratio calculated as:

where

For meaning practically does not change. For low meaning it changes linearly with the change .

A reasonable value the default is 1000. However, for holes with complex (rough) geometry, it may be smaller. 50. For very smooth geometry, it can be set to 50000.

The average fluid velocity is:

The volume consumption is:

where

If the check box is Moving body if withdrawn, the volume costs in ports B and A are calculated as:

where

If the check box is Moving body installed:

where — hull speed in port CA.

The hydrodynamic force is determined by estimating the change in momentum. This force tends to close the valve. For a steady-state fluid flow, the hydrodynamic force is:

where — the angle of inclination of the jet, equal to half the angle of the saddle cone.

Dependence of the hydrodynamic force from the rise It is defined as follows:

The power in port RA is calculated as:

where — the power that enters the RB port.

If the check box is selected Moving body, and the hull movement is modeled, then the force in the port CA is calculated as:

where