MULTLABFEM-UNICAMP

UNICAMP SETTING PROPERTIES USING INFORM

• The use of In-Form is introduced by means of examples to the user get acquainted with the syntax.

• A sequence of workshops present two ways of setting materials properties

• This first way explores the VR Editor capabilities and the use of PROPS file

• The second way uses the In Form.

• There are other ways, usually employed in the past, but are still useful –> go to Properties-old

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UNICAMP P

RO

PE

RT

Y

LIS

T

•

PIL variable SI units nature

RHO1 kg/m**3 first- phase density

DRH1DP m**2/Newton proportionate change with pressure

RHO2 kg/m**3 second - phase density

DRH2DP m**2/Newton proportionate change with pressure

ENUT m**2/s kinematic turbulent contribution to effective viscosity

ENUL m**2/s kinematic laminar (reference) viscosity

PRNDTL(indvar) > 0 dimensionless the Prandtl or Schmidt number

PRNDTL( indvar) < 0 dimensionless

or joules*degC/m

if indvar is enthalpy or temperature

PRNDTL(indvar) < 0 m**/s if indvar represents another scalar

PHINT(indvar) according to indvar equilibrium interface value for the first phase

PHINT(indvar) according to indvar equilibrium interface value for the second phase

TMP1 degCelsius temperature when first - phase enthalpy is solved for

TMP2 degCelsius temperature when second - phase enthalpy is solved for

EL1 m first- phase turbulence length

EL2 m second - phase turbulence length

CP1 joule/(kg*degC) constant - pressure specific heat of phase 1

CP2 joule/(kg*degC) constant - pressure specific heat of phase 2

DVO1DT 1/degC proportionate change of first - phase specific

volume (i.e. reciprocal of density) with tempe rature

DVO2DT 1/degC proportionate change of second - phase specific

volume (i.e. reciprocal of density) with temperature

EMISS 1/m absorptivity = proportion of radiation which is absorbed per unit length

SCATT 1/m proportion of radiation which is scat tered per unit length

MULTLABFEM-UNICAMP

UNICAMP WORKSHOP ON SETTING MATERIAL

PROPERTIES USING INFORM

Two workshops are based on the case: heat transfer in a cylindrical pipe whose parameters are described below:

• The pipe radius and length are 0.05m and 7.5m with 30x30 grid. The fluid is air using Ideal Gas Law (IMAT = 2). Consider the reference pressure and temperature of 105Pa, 273K.

• The inlet velocity and temperature is 0.15m/s and 20C. The north wall is held at constant temperature of 100C.

The q1 file of this case is available for download (wksh_if_prps1)

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UNICAMP WORKSHOP ON SETTING MATERIAL

PROPERTIES USING PROPS file

The PROPS file (stored at phoenics\d_earth directory) is where phoenics stores its properties lybrary.

Lets inspect the PROPS file…

One can edit the PROPS file as well as add new materials.

If one adds a new material the IMAT range has to be obeyed:0 – 59 – Gases60-99 – Liquids100 – 197 – Solids

The inconvenient is the fact that if you change computers you also have to move the edited PROPS file to the new computer

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UNICAMP SETting PRoPertieS by selecting materials

When one material fills the whole domain the following statement in the Q1-file suffices:

SETPRPS (argument1, argument2) where:

• argument1 = 1 or 2, according to the phase in question, and

• argument2 is the reference index of the material in the PROPS file, IMAT, which appears between < and >: brackets at the left-hand border of the file.

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UNICAMP EXAMPLE: SETPRPS

For example: SETPRPS(1,0)

dictates that the properties will be those of atmospheric air, because that is the significance of IMAT=0 .

Likewise, SETPRPS(2,67)

would set the second-phase fluid to be water with the properties pertaining to 20 degrees Celsius.

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Setting properties which vary in accordance with formulae coded in GXname files

The workshop problem is set up within VR by selecting material (2): “air as an Ideal Gas”. If the user inspect the PRPS file for IMAT =2 he will find for RHO1 and ENUL the entries GRND5 and GRND2.

They set the properties in accordance with GREX files, i.e. , fortran coded lines which perform as indicated below:RHO1=GRND5 selects density= RHO1B*(p1+PRESS0)/(t1+TEMP0)

The gas constant is, 1/RHO1B

ENUL= GRND2 set ENUL= ENULA + ENULB * t1 + ENULC * t1 ** 2 .

Inspect RESULT file and check the constants rho1A&B, enulA,B&C. The whole problem could be set within q1 file declaring the constants rhoA&B as well as enulA,B&C, also setting rho1=grnd5 and enul=grnd2. This is the so called ‘old fashion’ way to set up properties.

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UNICAMP RESULTS WKSH_IF_PRPS(1)

Contour plots of temperature, density and kinematic viscosity for future comparison purposes.

The results come from a q1 file selecting material (2), no property formulae were inserted so far, just built in formulas.

Go to slide (6).

TEMPERATURE

DENSITY

ENUL

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UNICAMP Example: INFORM SETTINGS Properties are set by In-Form with the command PROPERTY:

(PROPERTY of VAR at Patchname is Formula [with Optional] )

With is a limitation by IMAT, TIM, or other PIL variables.Also the IF conditional may be applied

Example1:(PROPERTY of RHO1 at BLOCK1 is 5.2*TEM1 + 1000 with IF(TIM >100))Means that rho1 at patch name BLOCK1 is set by the formula above only for time greater than 100

Example2:(PROPERTY of RHO1 is 5.2*TEM1 + 1000 with IMAT >100)Means that rho1 is set by the formula at the cells where imat >100, i.e., only for solid materials)

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Application: INFORM SETTINGS FOR WKSH_IF_PRPS(2)

ERASE: SETPRPS(1, 2) in Group 9 at the Q1 file At group 9 insert the lines below: Inform9BeginREAL(EA,EB,EC) ! Declares three real constantsEA=-4.946790E-06EB=4.58394E-08EC=8.097400E-11 evaluate rho1 using Ideal Gas Law(PROPERTY RHO1 IS (P1+PRESS0)/(287*(TEM1+TEMP0))) evaluate enul as a function of the temperature(PROPERTY ENUL IS EA+EB*(TEM1+TEMP0)+EC*(TEM1+TEMP0)^2)(PROPERTY CP1 IS 1004) ! Sets specific heat thermal conductivity is transmitted thru PRNDTL(TEM1) in G9 Inform9End

The statements Inform_Begin and Inform_End always start at the 3rd column.

You are asked to compare your results against the results on slide(4)If you don’t succeed writing these lines, download wksh_if_prps(2)

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UNICAMP 2nd WORKSHOP ON SETTING MATERIAL

PROPERTIES USING INFORM

The proposition now is to insert inside the pipe an obstruction like an orifice of material 198 (solid&friction).

In order to do so, it will be used the command INITIAL to set the material aluminum at the correct position.

(INIT[IAL] of Var [at PatchName] is Formula [with Options] )

sets a initialization of Var variable at region described by PATCH command with PatchName name by Formula calculated. Var is any 3D-stored variable. The "with Options" element contains options which specify the action of statement:

INFOB_n IMAT=iprp IF(condition)

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INFORM SETTINGS FOR WKSH_IF_PRPS(4)

At group 7 insertSTORE(PRPS)At group 11 insert the lines below: Inform11Begin define the patch where material 198 will be set in:PATCH(BLCK,VOLUME,1,1,NY/2,NY,NZ/6, NZ/6,1,1) set prps to material 198(INITIAL OF PRPS AT BLCK IS 198) Inform11End

Note: PATCH command allow definitions like fractions of the NZ, NY and NX. Their advantage lies on the independence of the number of cells in each direction. For this case, the patch will be always at half of NY cells and at 1/6 of NZ cells, no matter how large or small NY and NZ are.

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RESULTS FOR WKSH_IF_PRPS(4)

• Compare your results against the velocity field after orifice. The relaxation setting must be adjusted from previous wksh.

• If you don’t succeed writing these lines, download wksh_if_prps(3)

• As an alternative to , one could insert object directly from VR, download wksh_if_prps(4) to check it out.

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END OF THE PROPERTIES WORKSHOP