Bistra Announcement

7/26/2019 Bistra Announcement

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PHYSIBEL

simulation of transient heat transferin 2D free-form objects



Introduction

The Physibel program BISTRA allows simulations of transient heat

transfer in 2D free-form objectsThis sli!e show highlights

" how to sol#e a 2D transient problem using BISTRA

$with RAD%&' option(

" useful application e)amples

- groun! heat losses an! frost insulation

- fire engineering * steel-concrete floor

- fire engineering * win!ow frame

- harmonic analysis of walls

- temperature of heate! + unheate! rooms

- thermal effect of solar ra!iation on fa,a!es



Solving a 2D transient heat transfer

roblem using BIS!"# Problem !efinition The analysis of a fictitious problem shows the powerful performances of BISTRA




roblem using BIS!"#

Problem !efinition .aterials with non-linear thermal properties/ phase change materials $P%.( an!

an argon fille! gas layer boun!e! by a low emissi#ity surface occur




roblem using BIS!"#

Problem !efinition The water temperature in the tubes rises an! a heat is release! at the P%. bor!er

'on-linear con#ection an! ra!iation occur




roblem using BIS!"#

2 Problem implementation0 BISTRA program interface 1 $indo$s

bitma

colours

measures

borderline bc%s

functions



2 BISTRA program interface bitma $indo$

automatic filling of line dra$ing

each colour corresonds to a material

or to a boundar& condition

dra$ing and fill tools available for

modif&ing the bitma as in BIS'(



2 BISTRA program interface colours $indo$colour use! in bitmap

material * boun!ary con!ition type

specific stan!ar! rule/ for e)ample use! to calculate the eui#alent thermal con!ucti#ity

thermal con!ucti#ity

constant or

temerature

deendent

function

surface IR emissi#ity

!ensity

specific heat

constant or

temerature

deendentfunction

temperature $global/ air/ ra!iant(

constant or

time function

global or con#ecti#e surface coefficient heat source stan!ar! rule coefficientsconstant or time function



2 BISTRA program interface functions $indo$

arameter or file defined

functions

function grah vie$



2 BISTRA program interface measures $indo$

34 m

si)e for automatic triangulation



2 BISTRA program interface calculation arameters

start-u calculation duration allo$s

transient start condition

multile iteration c&cles for non-linear

roblems

both linear and non-linear radiation

model $ith automatic vie$ factor

calculation

recalculation of temerature deendent

*uantities at each time ste



5 BISTRA calculation results grahic outut $indo$












5 BISTRA calculation results animation outut



BISTRA allows transient thermal simulations accor!ing to

6' IS& 5573Thermal performance of buil!ings - 8eat transfer #ia the groun! -

%alculation metho!s

6' IS& 5795

Thermal performance of buil!ings - Thermal !esign of foun!ations

to a#oi! frost hea#e

BIS!"# alication e+amle ,

ground heat losses and frost insulation







BIS!"# alication e+amle 2

fire engineering steel-concrete floor

BISTRA allows fire engineering

simulations accor!ing to the

6:R&%&D6S for structural calculations

A fire cur#e $typically IS& ;5<( isassume! at one si!e of the construction

The simulation of the heat transfer by

ra!iation/ con#ection an! con!uction

allows pre!icting the temperature

e#olution in the construction

Temperature !epen!ent material

properties $steel/ concrete/ ( are

consi!ere!



4 min



53 min





=3 min



74 min



93 min





BIS!"# alication e+amle .

fire engineering $indo$ frame



















BIS!"# alication e+amle /

harmonic anal&sis of $alls







BIS!"# alication e+amle 0

temerature of heated 1 unheated rooms





BIS!"# alication e+amle

thermal effect of solar radiation on fa3ades

>or a south fa,a!e $!ouble gla?ing/

aluminium frame/ opaue insulation panel(

in Brussels the temperature !istribution is

calculate!/ ta@ing into account the solar

ra!iation transmitte! through the gla?ing an!

absorbe! in the fa,a!e

























4 about .D 4

The Physibel program 5(L!"# allows simulations of transient heat

transfer in 5D objects !escribe! with rectangular bloc@s&TRA has the same basic simulation performances as BISTRA

BISTRA !ata can be importe! C The bitmap pi)els are treate! as

small rectangular bloc@s

>urther information can be foun! on0 http0wwwphysibel

be#3n2#ohtm

http://www.physibel.be/v0n2vo.htm








PHYSIBEL

Heir$eg 2, B-6667 8aldegem Belgium

hone 9.2 07 :,,/.2 fa+ 9.2 07 :,:;/2

$$$<h&sibel<be mail=h&sibel<be

than> &ou for &our attention ?

made visible b&

http://www.physibel.be/


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Bistra Announcement