/EBCS/VALVOUT

Block Format Keyword Describes the elementary boundary condition to describe outlet valve (imposed density and pressure).

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
/EBCS/VALVOUT/ebcs_ID/unit_ID
ebcs_title
surf_ID
C
fct_IDpr Fscalepr
fct_IDrho Fscalerho
fct_IDen Fscaleen
lc r1 r2

Definition

Field Contents SI Unit Example
ebcs_ID Elementary boundary condition identifier.

(Integer, maximum 10 digits)

unit_ID Unit identifier

(Integer, maximum 10 digits)

ebcs_title Elementary boundary condition title.

(Character, maximum 100 characters)

surf_ID Surface identifier.

(Integer)

C Speed of sound.

Default = 0 (Real)

[ m s ] MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaamWaaeaada Wcaaqaaiaab2gaaeaacaqGZbaaaaGaay5waiaaw2faaaaa@39DE@
fct_IDpr Function f p r ( t ) identifier for pressure.
= 0
P = F s c a l e p r
= n
P = F s c a l e p r f p r ( t )

(Integer)

Fscalepr Pressure scale factor.

Default = 0 (Real)

[ Pa ]
fct_IDrho Function f r h o ( t ) identifier for density.
= 0
ρ = F s c a l e r h o
= n
ρ = F s c a l e r h o f r h o ( t )

(Integer)

Fscalerho Density scale factor.

Default = 0 (Real)

[ kg m 3 ]
fct_IDen Function f e n ( t ) identifier for energy.
= 0
E = F s c a l e e n
= n
E = F s c a l e e n f e n ( t )

(Integer)

Fscaleen Energy scale factor.

Default = 0 (Real)

[ J ]
l c Characteristic length.

Default = 0 (Real)

[ m ]
r1 Linear resistance. 5

Default = 0 (Real)

[ kg m 2 s ]
r2 Quadratic resistance. 5

Default = 0 (Real)

[ kg m 3 ]

Comments

  1. Input is general, no prior assumptions are enforced! Verify that the elementary boundaries are consistent with general assumptions of ALE (equation closure).
  2. Compatible with /MAT/LAW6 only.
  3. Density, pressure, and energy are imposed according to a scale factor and a time function. If the function number is 0, the imposed density, pressure and energy are used.
  4. This keyword is less than four or equal to six (non-reflective frontiers (NRF)) using:

    P t = ρ c V n t + c ( P P ) l c

    Pressure in the far field P is imposed with a function of time. The transient pressure is derived from P , the local velocity field V and the normal of the outlet facet.

    Where, l c is the characteristic length, to compute cutoff frequency f c as:

    f c = c 2 π . l c

  5. A resistance pressure is computed and added to the current pressure.
    P r e s = r 1 V n + r 2 V n | V n |

    It aims at modeling the friction loss due to the valves.