DCV 32 Floating - MapleSim Help

DCV 32 Floating

3-way 2-position directional control valve

Description

The DCV 32 Floating component is a three-port, two-position valve. Port P (pump) is always connected to port A; the spool input determines whether it is also connected to port T (tank). The area between pairs of ports varies as a function of the spool input signal, $s$, and the parameters ${A}_{\mathrm{max}}$, ${A}_{\mathrm{min}}$, and $\mathrm{band}$. The following table gives the areas for the two end values.

 Spool Input P-A P-T 0 ${A}_{\mathrm{max}}$ ${A}_{\mathrm{max}}$ 1 ${A}_{\mathrm{max}}$ ${A}_{\mathrm{min}}$

Transitions are centered at the midpoint, with the width given by the $\mathrm{band}$ parameter, as shown in the following diagram.

 Formulation Approaches One of two approaches can be selected for modeling the flow in the device. When the boolean parameter $\mathrm{Use constant Cd}$ is true, a constant coefficient of discharge (${C}_{d}$) is used, otherwise a variable coefficient of discharge with maximum value (${C}_{d\left(\mathrm{max}\right)}$) and a critical flow number (${\mathrm{Crit}}_{\mathrm{no}}$) are used.
 Optional Volumes The boolean parameters Use volume A, Use volume P, and Use volume T, when true, add optional volumes ${V}_{A}$, ${V}_{P}$, and ${V}_{T}$ to ports A, P, and T, respectively. See Port Volumes for details. If two orifices or valves are connected, enabling a volume at the common port reduces the stiffness of the system and improves the solvability.

Connections

 Name Description Modelica ID $\mathrm{portA}$ Hydraulic port A portA $\mathrm{portP}$ Hydraulic port P (pump) portP $\mathrm{portT}$ Hydraulic port T (tank) portT $s$ Spool input signal s

Parameters

General

 Name Default Units Description Modelica ID ${A}_{\mathrm{max}}$ $1·{10}^{-4}$ ${m}^{2}$ Maximum orifice opening area; available when Use scales is true Amax ${A}_{\mathrm{min}}$ $1·{10}^{-12}$ ${m}^{2}$ Minimum orifice opening area (leakage) Amin $\mathrm{band}$ $0.1$ Transition length in normalized spool displacement units band $\mathrm{Flip Configuration}$ $\mathrm{false}$ True (checked) flips the order of the valve configuration Switch

Orifice

 Name Default Units Description Modelica ID $\mathrm{Use constant Cd}$ $\mathrm{true}$ True (checked) means a constant coefficient of discharge is implemented otherwise a variable ${C}_{d}$ is used in flow calculations UseConstantCd ${C}_{d}$ $0.7$ Flow-discharge coefficient; used when $\mathrm{Use constant Cd}$ is true Cd ${\mathrm{Re}}_{\mathrm{Cr}}$ $12$ Reynolds number at critical flow; used when $\mathrm{Use constant Cd}$ is true ReCr $\mathrm{Coeff}$ $0.7$ Maximum flow-discharge coefficient; used when $\mathrm{Use constant Cd}$ is false Coeff ${\mathrm{Crit}}_{\mathrm{no}}$ $1000$ Critical flow number; used when $\mathrm{Use constant Cd}$ is false Crit_no

Optional Volumes

X corresponds to ports A, P, and T.

 Name Default Units Description Modelica ID $\mathrm{Use volume X}$ $\mathrm{false}$ True (checked) means a hydraulic volume chamber is added to portX useVolumeX ${V}_{X}$ $1·{10}^{-6}$ ${m}^{3}$ Volume of chamber attached to portX Vx