Software Manual for Operating Particle " Displacement Tracking Data ...

NASA

Technical

Memorandu_m

103720

....

Software Manual for Operating Particle Displacement Tracking Data Acquisition and Reduction System _

Mark P2 Wernet Lewis Research Center ................................ Cleveland, Ohlo

January

" -_

.......

1991

Nq i-Z =-:'-(NASA-TM-I03770) OpERATI"!G

UATA ('4ASA)

5OFTWt_K_

PAe.TICLE

._COUTSITI@N 4t _

p

MANUt_L

r)ISPLACEMENT

AND

REOUCTION

04S 3


RUN386POINTS IARG where: RUN386: Microway DOS-Extenderprogramloader IARG = 0, or no argument:Video SevenVRAM VGA 1024×768x16colors IARG = 1: IBM VGA 640×480×16colors IARG = 2: IBM EGA 640x350x16colors Regardlessof the screenresolution,the printer resolutionis always 300dpi. Other video boardsand screenresolutionscan be supportedby selectingthe appropriateHALO Professionalscreendriver and video mode. The programqueriesthe userwherethe files are to be displayed;on the computerscreen,or on the systemprinter. The computerscreenis the default. Next, the programqueriesfor the numberof files to be displayedor printed. The useris then askedto enterthe file name(s)to be plotted. After all the file nameshavebeenentered,the programwill either sequentially display the imageson the computerscreen,or print 2 copiesof eachimage on the printer. For on screendisplays,the userpressesthe returnkey when finished viewing the graph to eitherdisplay the next imageor end the program. For the on screendisplays,both color and symbolshapesare u_edtodistinguish the particle imagecenlroidsfrom different fields in the 5-field sequence.Color coding the symbols makesup for the low resolutionof the computerscreen. However,on the printer hardcopy, only black and white are available. The symbolsizeusedfor both the onscreendisplaysand for hardcopiesareapproximatelytwice aslarge as a normalpixel would be from a time history file 640x480pixel image. The key to the symbol shapesand colorsare displayedat the top of the graph,just underneaththe file name. The five symbolsusedare:

Exposure 1 2

#

Symbol

3 4 5

Hence, vector

a successful would appear

panicle as:

Type • + * x

displacement

•

record

+

o

18

which

•

would

X

be identified

as a valid

velocity

The

velocity

underneath

vector

corresponding

the symbols

to the particle

just as an example.

encoding.

pattern

direction

history

the particle

printer

is used

for generating

the 300 dpi image.

A Virtual

Raster

created

within

the computer's

extended

which

tbe equivalent

dpi image.

The

the printer.

Two

minutes. may

program

to the main

be present.

page

Extended data

a banner menu.

memory

indicating

Typical from

must

and

has

times

style

(VRI)

is being

device

80386

with the VRI driver.

is

of a 300

transferred

of the print

an expanded

to the

exposure,

resolution

on a 25MHz

then

due

the fifth

Interface

that the image

print

here

of an HP-Laserjet

At the completion

the printer,

be used

in figure

the × marks

full resolution

are generated.

is ejected

file is shown

The

memory,

of the graph

If an all black

a time history

left to right.

displays

copies

returns

from

the first exposure

is shown

is unambiguous

thus,

is moving

• marks

particle

time

the program

The

displacement

The

to

operation,

PC are 3-4

memory

A sample

driver print

out of

3 below.

FT300310.TS1 • 111" K_pl_l.vs

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ure

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produced

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from

the POINTS

is a large

collection

program

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.

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.

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I 480

displaying

.Ik 't"I

•

a typical

I 640

time history

PDTGRAF The

PDTGRAF

program

of data 19

analysis

and plotting

routines

for

file.

interpretingand displaying program

are the velocity

the reduced velocity vector data. The input data to the PDTGRAF vector map files generated either from the PDTLS or BSPDTLS

programs. The PDTGRAF resolution. The argument values

program utilizes a command line argument for selecting the current display format of the program command line call and range of command line are:

C:\>

RUN386

PDTGRAF

where: RUN386:

IARG

Microway

IARG = 0, or no argument: IARG = i: IARG = 2:

DOS-Extender

Video Seven VRAM IBM VGA 640x480x16 IBM

EGA

resolution is always 300 dpi. Other by selecting the appropriate HALO

PARTICLE

DISPLACEMENT

VELOCITY

VECTOR

PROCESSING ISO-VELOCITY Written

displayed

queries

in .

The

a banner

message

DATA

& PRINTING

ANALYSIS ON

SYSTEM

HP-LASERJET

MODES: VELOCITY VECTOR INTERPOLATION, CONTOURS, AND STREAM FUNCTION COMPUTATION by M. P. Wernet Revised 10/31/90

(I) (2) :

always

shows

#1)

TRACKING

GRAPHING

video

screens before the data processing menu the main menu screen. The functions of

#1, displayed by the PDTGRAF program individual frames or a series of frames: (SCREEN

in all of the program

colors

colors

The PDTGRAF program displays multiple data entry is reached. There are three data entry screens before each data entry screen are described below. The initial screen, screen and options of processing

loader

VGA i024×768x16 colors

640x350x16

regardless of the screen resolution, the printer boards and screen resolutions can be supported Professional screen driver and video mode.

program

PROCESS PROCESS

to the user default

INDIVIDUAL A SERIES

OF

in the PDTGRAF

option

is selected

20

FRAMES *.DS#

FRAMES

program,

a default

by just pressing

input

the return

value key.

is The

defaultoption for the abovescreenis option 2. In mostinstancesthe format of the datatype to be readarealso denotedin brackets[]. For example,integerreadsaredesignated[I2], real datatype readsare denoted[F6.2]. The individual frame option is for plotting singlevelocity vector map files processedusing the BOUND5 andPDTLS routines. Screen#2 asksthe userhow many individual files areto be read,and thenqueriesthe userfor the file name(s)of the input datafiles. For eachdata file nameentered,the useris alsoaskedto entera scalefactor for the datafile. The scale factor refers to magnitude of the velocity vectors in each file relative to the other data files entered.

The

scale

times and defines For only a single to be read times

factor

in, VECTOR

of 5 and

is used for scaling

data

sets with different

inter-field

the magnitude of the velocity vectors in the subsequent input file, a scale factor of 1 is appropriate. However,

10 field

1.DAT

and VECTOR2.DAT,

intervals

(5 x 1/60, and

which

were

recorded

10 × 1/60 second

acquisition

graphing operations. if two data files are with inter-frame

intervals),

then

the ratio

of

the velocity vector magnitude scales is 2:1. The scale for the 5/60 second data set would be 1.0, while the scale for the 10/60 second data set would be 0.5. Hence, the ratio of the interframe

acquisition

velocity

data

entered

first,

The

times

set (shortest followed

PROCESS

the number Each series

of series contains

vector

series data

inter-frame

the different

time).

The

sets relative

maximum

slower

OF *.DS FRAMES

data

velocity

(option

velocity data

data

to the maximum set is usually

sets.

2, screen

#1)

also queries

the user

for

to be read, and then queries the user for each series file name root. 5 data files. The user enters the file name root such as 'TEST010.DS',

will read

specified.

for scaling

by the successively

A SERIES

and the program each

is used

The

files.

Again,

acquisition

times

relative

In the PIV

work

performed

in data user

files TEST010.DS

is asked

the scale to each

factors

1, TEST010.DS2 a velocity

are used

to scale

scale data

....

for each

TEST010.DS5 series

for

of velocity

sets with different

inter-frame

other.

at LeRC,

encodes some of the experimental series file names:

to enter

a file naming

setup

parameters

B0536025.DS

convention in the file

has been name.

adopted

which

For example,

in the

1

B0536025.DS2 B0536025.DS3 B0536025.DS4 B0536025.DS5 The letter inter-frame

'B' is used to denote the experiment type. The '05' section is used to encode the time in field intervals, therefore, '05' means 5 field intervals, or 5/60 of a second

between acquired images in the sequence. The 'B'. The '025' number indicates the processing processing

of the original

sets generated

from

PIV

the original

images. 25-field

The

'36' is the run number of experiment threshold level used in the boundary

suffLxes

image

'DS#'

sequence.

21

are used Typically,

to denote several

type

the five data data

sets with

different inter-frameintervals areplottedon the samegraph. Eachdataset hasapproximately a 10:1dynamic range(rememberthe 10 pixel displacements).Hence,by addingthreedata seriestogetherwith inter-frameacquisitiontimes of 05, 10, and 20, yielding velocity magnitudescalesof 1, 0.5, and0.25, onecan obtain a velocity diagramwith a dynamic range of (10 × 1/0.25)40:1. The necessityof simplifying the dataseriesentry procedurehasdriven the developmentof the following file entry coding. For examplesupposethe userwantsto enter 3 data seriesfiles namedB0536025.DS(1-5), ,B1036025.DS(1-5),andB2036025.DS(1-5).When queriedby the programfor the numberof seriesto be readin, the userenters3 just as they normally would. Insteadof typing the entire file nameroots for all threeseriesandtheir respectivevelocity vector magnitudescales,however,when promptedfor the first seriesfile nameroot the user entersthe following string: $B-05-10-20-36025.DS The programhasbeentold that 3 seriesare to be read. The '$' characterinforms the programthat a codedstring hasbeenenteredwhich containsall 3 file nameroots. The hyphensin the codestring are usedto delimit the inter-frameacquisitionintervalsin integral multiples of video fields (1/60 second). For consistency,two field positions(i.e. -05- not -5-) are usedfor all inter-frametime intervals. The inter-frameacquisitionintervalsmust be enteredin orderfrom shortestto longest,which correspondsto the highestto lowest velocities. The programgeneratesthe file namesandautomaticallyreadsin all threedata seriesB0536025.DS(1-5),B1036025.DS(1-5),andB2036025.D'S(1-5)-, for a total of 15 files. After enteringthe codedfile namestring, the useris promptedto enterthe scalefactor for the first series. The user shouldenterthe scalefactor desiredfor the maximumvelocity data series,which is the first dataseriesin the codedstring. The scalefactor can be greaterthan or lessthan unity. The value of the scalefactorsetsthe relative length of all of the velocity vectorsin the graphs. If the vectorsare too short,thenincreasethe scalefactor, or, if the vectorsare too long, thendecreasethe scalefactor. The programusesthe userenteredscale factor and the inter-frameacquisitiontimes to calculatethe scalefactorsfor all the other data series. In the exampleeaseabove,the inter-frametimes are5, 10,and 20 field intervals. If the userentereda scalefactor of 1.0 for dataseriesB0536025.DS(1-5),then the scalefactors for the other two dataserieswould be computedto be 1.0 × 05/10 = 0.5 for B1036025.DS(15), and 1.0 × 05/20 = 0.25 for B2036025.DS(1-5).The automateddataentry scheme simplifies the dataentry processfor the user. After all of the data files havebeenread,the programqueriesthe userfor the velocity scale. The velocity scaleis the conversionfactor from the particle imagepixel displacementsto real world dimensionsof cm/secor m/sec. If no velocity scaleis entered,(the default option), then a scalekey is not includedin the velocity vectorgraphs. The velocity scaleis computed basedon the highestvelocity dataset,or correspondingly,the data setwith the minimum inter-frameexposuretime. The velocity scaleis computedfrom two parameters,the image scaleLs,_ [m/pixels], andthe total exposuretime AT. 22

The imagescaleis obtainedby placing a referencescale(ruler) in the planeof the light sheet illumination. The data acquisitionprogramPDTMNLS "Acquire a SingleImage" operation can be usedto acquirean imagecontainingthe referencescale. Then the PDTMNLS "Analyze Imagefor Boundaries"operationcanbe usedto find the numberof pixels between two pointson the referenceobject. Alternatively, the EPIX interactivemenubasedimage processingpackage4MIP can be usedto acquirean imageanddeterminethe numberof pixels betweentwo points (x_,y_)and (x2,y2)on the referenceobject. The distancebetween the two points is given by D=[(x2-x_) 2 + (y2-yl)2]_r2.The image scaleis then simply the physicaldistancebetweenthe two referencepointson the scaleobject divided by the distance in pixels,D, betweenthe two points. A typical PIV setuphasan image scaleof approximatelyL,,_ = 2001.tm/pixel,which correspondsto a 128×96mmfield of view in a 640×480pixel image.

The total exposuretime is the sum total of the four inter-frameacquisitionintervals. For example,if the inter-frameimageacquisitioninterval was5 video fields, then the total exposuretime is AT = 4×5×1/60 = 0.333 seconds. The total time interval corresponds the time elapsed particle The

from

on field

velocity

quantities

scale

given

when

the particle

was

first recorded

on field

#1 to the last record

of the

#5. is computed

above,

from

the product

the velocity

scale

Ls,_e and

1/AT.

Hence,

for the example

is:

Vs,,e = L_,l_ / AT = 200l.tm/pixel Vs,_

= 6.0E-4

When a non-zero velocity scale is entered velocity vector plots. The displayed scale

/ 0.333

seconds

m/pixel-sec

above, a velocity scale is displayed can be either the maximum velocity

in the 2-D in the data

set,

which is used as a reference scale for the velocity vectors in the graph, or the velocity scale can be the mean velocity of all of the velocity vectors in the data set. After the user enters the velocity scale into the program, the program queries the user use in the scale computation, the maximum velocity or the mean use the maximum vector

data

velocity

velocity.

to find

vector

Alternatively,

to compute

the mean the graph

vector

at under

velocity

vector

option

with

vector

the mean

23

searches

maximum

magnitude

with the numerical

can be selected,

from

all of the data

magnitude. vector

type of velocity to The default is to

the program

The

title along

magnitude

with the mean

title along

velocity,

magnitude.

the graph

the mean velocity

is also computed

drawn under cm/sec.

the maximum

the maximum

is drawn

in cm/sec. deviation

For

for which velocity.

of the vector,

causes

vectors. and

reference

value

which

A reference

magnitude

the velocity

velocity standard

the program

The

standard vector

deviation

is in

The last parameterto be enteredin screen#2 is the graphtitle. By default, the program generatesa title from the last enteredfile name. The default title is acceptedby just pressing the return key. If a different title is desired,type the new title andthen pressthe returnkey. The maximumtitle length is 40 characters.For example,if singledatafile input is selected, the default title is exactly the last datafile name. If seriesdatafile input is selected,then the defaulttitle is the last enteredfile nameroot with the addedsuffix '(1-5)', denotingthat a seriesof datafiles havebeenread. Hence,if the seriesfile nameroot was 'B0536025.DS', the default title is 'B0536025.DS(1-5)'. Again, if a different title is desired,type in the new file nameat the prompt andpressreturn. Finally, If a codedmultiple seriesfile root is entered(beginningwith a '$'), then the defaultfile nameis the codedstring minus the '$' characterand with the addedsuffix '(1-5)', denotingthat all of the codedserieshavebeen read. In summary,an exampleof a screen#2 displayfrom PDTGRAFis shownbelow, where the userinputsare shownin BOLD: (SCREEN#2)

1l PARTICLE DISPLACEMENT

DATAALYSIS II

ONE SERIES, OR MULTIPLE SERIES TO BE ADDED [I2] : 1 FOR AUTOMATED SERIES INPUT ENTER $X-##-##-##-XXYYY.ZZ ENTER SERIES# 1 FILE ROOT [A40]: B0536025.DS ENTER MAGNITUDE SCALE FOR FILE SERIES# 1 [F6.2]