jet flow in a combustion chamber

1. contacts
2. Paper digest
3. TODO Purpose of study
4. TODO Questions
5. FAQ
6. problem description
7. results
- 7.1. mixture fraction – defining the jet boundary
8. setups
9. source files
- 9.1. transient.case
10. Post-processing
11. theory
12. Video
- 12.1. Ignition of a turbulent methane jet
13. Reference
- 13.1. contacts
14. reseach groups
15. How to
- 15.1. 3D video
16. Results
17. Script FAQ

1 contacts

Chia-Fon Lee

Professor, Mechanical Science and Engineering Professor, ZJU-Illinois Joint Institute, College of Engineering

2 Paper digest

effects of transient rate of injection on high pressure diesel fuel jets

2.1 LES vs. RANS

s. som, 2012, Comparison of RANS and LES Turbulence Models against Constant Volume Diesel Exper-iments

2.2 Dynamics of Transient Fuel Injection, Mixing, and Auto-Ignition

https://tcrl.osu.edu/research/dynamics-transient-fuel-injection-mixing-and-auto-ignition

chemical kinetics

turbulence

2.3 rothamer research group, Experimental Studies of Transient Jets

https://rothamer.erc.wisc.edu/transientjets

2.4 the transient start of supersonic jets

2.5 decelerating transient turbulent jets

2009 Mark P B Musculus, JFM, entrainment waves in decelerating transient turbulent jets Doi: 10.1017/S0022112009990826

keywords: decelerating transient turbulent jet

why study it?

the majority of the combustion event occurs after the end of injection, during the decelration phase.

entrainment during the deceleration phase can be critical for engine performance.

2.5.1 Bing huan, 2012, physics of fluids

2.6 validi 2016, PhD thesis, Michigan State University

TJI in different combustion systems with DNS and LES

2.7 P wang, 2008,

what is new of wang(2008) compared with experimental result? 39, 2149–2164. Chen, C.J., Rodi, W., 1980. Vertical Turbulent Buoyant Jets—A Review of Experimental Data. The Science and Application of Heat and Mass Transfer. Pergamon Press, New York.

\( \omega = \nabla \times v \) S.V. Gordeyev and F. O. Thomas. Coherent structure in the turbulent planar jet. part

extraction of proper orthogonal decomposition eigenmodes and their self-similarity.

Journal of Fluid Mechanics, 414:145 – 194, 2000.

fundamentals of compressible flow

2.8 TJI assited combustion system 2016

PCh: pre-chamber
MCh: main chamber
RCMs: rapid compression machines
IC: internal combustion
SGS: sub-grid scale
PDF: probalility density function

conclusions: turbulence fields becomes fully developed by t=3τ₀ (P11)

τ₀ : flow through time

simulation performed up to t=17τ₀ (P11)

3 TODO Purpose of study

4 TODO Questions

10 realization of the les model ? Fig. 6, BIng Hu

inlet BCs

time step size

5 FAQ

5.1 is it a spark ignition (gasoline)?

yes

5.2 time step size in your LES ?

5.3 When does the main chamber start to burn/combust?

when the jet flow enter the main chamber

5.4 how to estimate the Mach number

ma=U/C

and

C=sqrt( γ R T)

how to define the reference temperature (T)?

answer: use local T at every computational point

5.5 mixture fraction calculation

mixture fraction, f, is defined as the mass fraction from fuel, i.e.

f=m_fuel/m_total

the question is how to define the sample area/cubic size in the post processing ?

answer: use the mesh size

6 problem description

intial conditions

inlet gas ma=u/c = 1.3 Re = ρ u L / μ =0.231*1102.95*0.0025 / density: pressure temperature velocity, u= 1102.95

c: speed of sound

c=sqrt(γ RT)

flow direction +x

7 results

axial and radial distribution of <Ux>, TKE, <u_i u_j>

jet spreading angle is 28 \degree based on emrirical estimation

7.1 mixture fraction – defining the jet boundary

f: mixture fraction, which is the mass

fraction that originated from the fuel stream. it is the local mass fraction of burnt and unburt fuel stream elements.

why use mixture fraction?

because atomic elements are conserved in chemical reactions. In turn, the mixture fraction is conserved scalar quantity, and therefore its governing transport equation does not have a source term. (ch8, theory guide, fluent)

How to calculate mass fraction in post processing?

you can define a small cubic/plane and calculate the mass ratio = mass_(fule)/mass_total the problem is the size of cubic/plane?

How to define the jet boundary?

8 setups

LES time step size: 5e-7s it is 0.0000005. The snapshots were saved every 500 steps, so for the data you have got, it is 0.0000005 * 500 seconds between two snapshots

inlet center (-0.432, 0, 0) flow direction, +x

9 source files

transient.case: scripts for paraview
(no term): automate naming of files attach _* at the end of filename

9.1 transient.case

FORMAT type: ensight gold GEOMETRY model: solution.pval.unsteady₁.geo VARIABLE scalar per node: density solution.pval.unsteady_*.density vector per node: v solution.pval.unsteady_*.v scalar per node: pressure solution.pval.unsteady_*.pressure scalar per node: temperature solution.pval.unsteady_*.temperature

TIME time set: 1 number of steps: 1 filename start number: 61 filename increment: 1 time values: 1.8385297551528

10 Post-processing

10.1 plot axial streamwise velocity–paraview

plotOverLine1.Source.Point1 = [0.0, 0.0, 0.0] plotOverLine1.Source.Point2 = [-0.435, 0.0, 0.0]

pay attention to x coordinate of point2, which is -0.435

10.1.1 script

#### import the simple module from the paraview from paraview.simple import * #### disable automatic camera reset on 'Show' paraview.simple._{DisableFirstRenderCameraReset}()

transient_312case = EnSightReader(CaseFileName='/home/kaiming/Documents/ZJU_Projects/Jet/data/transient₃₁₂.case') transient_312case.PointArrays = ['density', 'v', 'pressure', 'temperature']

transient_312case.PointArrays = ['v']

renderView1 = GetActiveViewOrCreate('RenderView')

transient_{312caseDisplay} = Show(transient_312case, renderView1)

transient_{312caseDisplay}.ColorArrayName = [None, ''] transient_{312caseDisplay}.GlyphType = 'Arrow' transient_{312caseDisplay}.ScalarOpacityUnitDistance = 0.0016420380639339577

renderView1.ResetCamera()

ColorBy(transient_{312caseDisplay}, ('FIELD', 'vtkBlockColors'))

transient_{312caseDisplay}.SetScalarBarVisibility(renderView1, True)

vtkBlockColorsLUT = GetColorTransferFunction('vtkBlockColors')

vtkBlockColorsPWF = GetOpacityTransferFunction('vtkBlockColors')

plotOverLine1 = PlotOverLine(Input=transient_312case, Source='High Resolution Line Source')

plotOverLine1.Source.Point1 = [-0.43700000643730164, -0.0860000029206276, -0.0860000029206276] plotOverLine1.Source.Point2 = [1.9165229048212495e-07, 0.0860000029206276, 0.0860000029206276]

plotOverLine1.Tolerance = 2.22044604925031e-16

plotOverLine1.Source.Point1 = [0.0, 0.0, 0.0] plotOverLine1.Source.Point2 = [-0.435, 0.0, 0.0]

viewLayout1 = GetLayout()

lineChartView1 = CreateView('XYChartView') lineChartView1.ViewSize = [473, 837]

viewLayout1.AssignView(2, lineChartView1)

plotOverLine1Display = Show(plotOverLine1, lineChartView1)

plotOverLine1Display.CompositeDataSetIndex = ¹ plotOverLine1Display.UseIndexForXAxis = 0 plotOverLine1Display.XArrayName = 'arc_length' plotOverLine1Display.SeriesVisibility = ['v_Magnitude'] plotOverLine1Display.SeriesLabel = ['arc_length', 'arc_length', 'v_X', 'v_X', 'v_Y', 'v_Y', 'v_Z', 'v_Z', 'v_Magnitude', 'v_Magnitude', 'vtkValidPointMask', 'vtkValidPointMask', 'Points_X', 'Points_X', 'Points_Y', 'Points_Y', 'Points_Z', 'Points_Z', 'Points_Magnitude', 'Points_Magnitude'] plotOverLine1Display.SeriesColor = ['arc_length', '0', '0', '0', 'v_X', '0.89', '0.1', '0.11', 'v_Y', '0.22', '0.49', '0.72', 'v_Z', '0.3', '0.69', '0.29', 'v_Magnitude', '0.6', '0.31', '0.64', 'vtkValidPointMask', '1', '0.5', '0', 'Points_X', '0.65', '0.34', '0.16', 'Points_Y', '0', '0', '0', 'Points_Z', '0.89', '0.1', '0.11', 'Points_Magnitude', '0.22', '0.49', '0.72'] plotOverLine1Display.SeriesPlotCorner = ['arc_length', '0', 'v_X', '0', 'v_Y', '0', 'v_Z', '0', 'v_Magnitude', '0', 'vtkValidPointMask', '0', 'Points_X', '0', 'Points_Y', '0', 'Points_Z', '0', 'Points_Magnitude', '0'] plotOverLine1Display.SeriesLineStyle = ['arc_length', '1', 'v_X', '1', 'v_Y', '1', 'v_Z', '1', 'v_Magnitude', '1', 'vtkValidPointMask', '1', 'Points_X', '1', 'Points_Y', '1', 'Points_Z', '1', 'Points_Magnitude', '1'] plotOverLine1Display.SeriesLineThickness = ['arc_length', '2', 'v_X', '2', 'v_Y', '2', 'v_Z', '2', 'v_Magnitude', '2', 'vtkValidPointMask', '2', 'Points_X', '2', 'Points_Y', '2', 'Points_Z', '2', 'Points_Magnitude', '2'] plotOverLine1Display.SeriesMarkerStyle = ['arc_length', '0', 'v_X', '0', 'v_Y', '0', 'v_Z', '0', 'v_Magnitude', '0', 'vtkValidPointMask', '0', 'Points_X', '0', 'Points_Y', '0', 'Points_Z', '0', 'Points_Magnitude', '0']

SaveData('/home/kaiming/Documents/ZJU_Projects/Jet/paraview/plot_over_line/v₃₁₂.csv', proxy=plotOverLine1) Disconnect() Connect()

10.2 axial velocity along centerline (Jet) – Matlab

input: velocity.csv file from paraview goal: post processing data, rerange data sequence

Read comma-separated value (CSV) file

syntax:

M = csvread(filename) reads a comma-separated value (CSV) formatted file into array M. The file must contain only numeric values.

>> filename='v.csv';

>> m=csvread(filename)

m =

 Columns 1 through 4:

   3.7053e-14   8.2965e-13   1.7973e-12   1.0000e+00

  -2.5358e-14   2.9547e-13  -2.3817e-13   1.0000e+00

   7.2622e-15   8.2172e-13  -4.0024e-13   1.0000e+00

  -4.2667e-14  -1.7888e-12   4.8413e-13   1.0000e+00

assign first column (U_x) to a variable 'u'

>>u=m(:,1);

change column vector to row vector (transpose)

>> u_x=u.'

change orders with fliplr

u_x=fliplr(u)

i.e. If A is a row vector,

A = 1 3 5 7 9

then fliplr(A) produces

9 7 5 3 1

change row vector to column vector

>> u_x=u_x(:)

u_x =

1.0042e+03

combine column vectors into matrix

>> u_vs_x =[u_x x] u_vs_x =

1.0042e+03 0.0000e+00 6.9823e+02 1.0000e-02 3.2162e+02 2.0000e-02 4.0328e+02 3.0000e-02

normalized U_x, and x

>> u_o=1102.95 u_o = 1103.0 >> u_x_nor=u_x/u₀ where u₀ is jet exit velocity

plotting with gnuplot/matlab >> x_nor=x/D where D is diameter of jet

plot(x_nor, u_x_nor)

10.2.1 scpirts

filename='v.csv'; % assign file to a variable m=csvread(filename); %Read comma-separated value (CSV) file u=m(:,1); % extract first column data, i.e. U_x u=u.' ; %change column vector to row vector (transpose) u_x=fliplr(u); % change orders of array, Flip array left to right u_x=u_x.'; % change row vector back to column vector (transpose) u₀=1102.95; % jet exit velocity u_x_nor=u_x/u₀; % normalize axial veloicty x=m(:,5) ; % extract 5th column data, i.e. x coordinates d=0.0025; % diameter of jet x_nor=x/d; % normalize axial distance plot(x_nor, u_x_nor) print -deps u_x.eps % save plot as eps image output=[u_x_nor x_nor]; % format a matrix save -ascii u_vs_x.txt output;

10.2.2 log

>> load v.csv error: load: unable to determine file format of 'v.csv'

solution: use csvread

10.3 Q-criterion

10.3.1 scripts

#### import the simple module from the paraview from paraview.simple import * #### disable automatic camera reset on 'Show' paraview.simple._{DisableFirstRenderCameraReset}()

transient_91case = EnSightReader(CaseFileName='/home/kaiming/Documents/ZJU_Projects/Jet/data/transient₅₁₄.case') transient_91case.PointArrays = ['density', 'v', 'pressure', 'temperature']

renderView1 = GetActiveViewOrCreate('RenderView') renderView1.Background =[1,1,1]

renderView1.ViewSize = [1117, 866]

densityLUT = GetColorTransferFunction('density')

transient_{91caseDisplay} = Show(transient_91case, renderView1)

transient_{91caseDisplay}.ColorArrayName = ['POINTS', 'density'] transient_{91caseDisplay}.LookupTable = densityLUT transient_{91caseDisplay}.GlyphType = 'Arrow' transient_{91caseDisplay}.ScalarOpacityUnitDistance = 0.0016420380639339577

densityLUTColorBar = GetScalarBar(densityLUT, renderView1) densityLUTColorBar.AutoOrient = 0 ## legend orientation densityLUTColorBar.Orientation = 'Horizontal' densityLUTColorBar.RangeLabelFormat = '%.2f' ## legend normalized position densityLUTColorBar.Position = [0.3, 0.1]

densityLUTColorBar.LabelColor = [0.0, 0.0, 0.0]

densityLUTColorBar.TitleColor = [0.0, 0.0, 0.0]

renderView1.ResetCamera()

transient_{91caseDisplay}.SetScalarBarVisibility(renderView1, True)

densityPWF = GetOpacityTransferFunction('density')

gradientOfUnstructuredDataSet1 = GradientOfUnstructuredDataSet(Input=transient_91case) gradientOfUnstructuredDataSet1.ScalarArray = ['POINTS', 'density']

gradientOfUnstructuredDataSet1.ScalarArray = ['POINTS', 'v'] gradientOfUnstructuredDataSet1.ComputeQCriterion = 1

gradientOfUnstructuredDataSet1Display = Show(gradientOfUnstructuredDataSet1, renderView1)

gradientOfUnstructuredDataSet1Display.ColorArrayName = ['POINTS', 'density'] gradientOfUnstructuredDataSet1Display.LookupTable = densityLUT gradientOfUnstructuredDataSet1Display.GlyphType = 'Arrow' gradientOfUnstructuredDataSet1Display.ScalarOpacityUnitDistance = 0.0016420380639339577

Hide(transient_91case, renderView1)

gradientOfUnstructuredDataSet1Display.SetScalarBarVisibility(renderView1, True)

contour1 = Contour(Input=gradientOfUnstructuredDataSet1) contour1.ContourBy = ['POINTS', 'density'] contour1.Isosurfaces = [0.7536712437868118] contour1.PointMergeMethod = 'Uniform Binning'

contour1.ContourBy = ['POINTS', 'Q-criterion'] contour1.OutputPointsPrecision = 'Single' contour1.Isosurfaces = [1000000.0]

contour1Display = Show(contour1, renderView1)

contour1Display.ColorArrayName = ['POINTS', 'density'] contour1Display.LookupTable = densityLUT contour1Display.GlyphType = 'Arrow'

Hide(gradientOfUnstructuredDataSet1, renderView1)

contour1Display.SetScalarBarVisibility(renderView1, True)

renderView1.ResetCamera(-0.437000006437, -0.363715648651, -0.0146765615791, 0.0155552132055, -0.0139937549829, 0.0155133698136)

renderView1.CameraPosition = [-0.3693876183825478, -0.14945995339693371, 0.18962885092966636] renderView1.CameraFocalPoint = [-0.3579576038702967, -0.006822062851817242, -0.0021144211493554846] renderView1.CameraViewUp = [0.6080912350865584, 0.61916691517865, 0.4968474423392544] renderView1.CameraParallelScale = 0.04229428955697712

viewLayout1 = GetLayout()

SaveScreenshot('/home/kaiming/Documents/ZJU_Projects/Jet/paraview/Q_criteria_colored_by_density₅₁₄.png' , layout=viewLayout1, magnification=1, quality=100)

Disconnect Connect

10.4 video of velocity contour

create multiple files with matlab
reading files in a loop

add time on screen

fixed label value LockDataRange not work

inlet fluid properties, and conditions

frequency

10.4.1 fixed label value

10.4.2 Python file I/O

open a file
read or write (perform operation)
Close the file

How to open a file? use open() function, which returns a file object

e.g.

>>> f = open("test.txt") # open file in current directory >>> f = open("C:/Python/readme.txt") # specifying full path >>> f = open("test.txt",mode='r',encoding='utf-8') # specifying mode, and encoding https://www.programiz.com/python-programming/file-operation

How to close a file? Method 1

f = open("test.txt",encoding = 'utf-8')

# perform file operations

f.close()

Method 2

use a try... finally block

10.4.3 loop in python

10.5 multiple slides with for loop

file: sliceForLoop.py

#### import the simple module from the paraview

from paraview.simple import *

#### disable automatic camera reset on 'Show'

paraview.simple._DisableFirstRenderCameraReset()

# for loop, 'Num' is number of loops

for Num in range(2):

    # create a new 'EnSight Reader' and assign it to a variable, 'transientcase'

    transientcase = EnSightReader(CaseFileName='/home/kaiming/Documents/ZJU_Projects/Jet/data/transient%i.case' %(Num+1))

    transientcase.PointArrays = ['v', 'density', 'pressure', 'temperature']

    # get active view

    renderView1 = GetActiveViewOrCreate('RenderView')

    # set a specific view size

    renderView1.ViewSize = [1022, 837]

    # get color transfer function/color map for 'density'

    densityLUT = GetColorTransferFunction('density')

    densityLUT.LockDataRange = 1

    # get opacity transfer function/opacity map for 'density'

    densityPWF = GetOpacityTransferFunction('density')

    # show data in view

    transientcaseDisplay = Show(transientcase, renderView1)

    # trace defaults for the display properties.

    transientcaseDisplay.ColorArrayName = ['POINTS', 'density']

    transientcaseDisplay.LookupTable = densityLUT

    transientcaseDisplay.GlyphType = 'Arrow'

    transientcaseDisplay.ScalarOpacityUnitDistance = 0.0016420380639339577

    # reset view to fit data

    renderView1.ResetCamera()

    # show color bar/color legend

    transientcaseDisplay.SetScalarBarVisibility(renderView1, False)

    # get opacity transfer function/opacity map for 'density'

    densityPWF = GetOpacityTransferFunction('density')

    # reset view to fit data

    renderView1.ResetCamera()

    #################

    ## slice

    ################

    # create a new 'Slice'

    slice1 = Slice(Input=transientcase)

    slice1.SliceType = 'Plane'

    slice1.SliceOffsetValues = [0.0]

    # init the 'Plane' selected for 'SliceType'

    slice1.SliceType.Origin = [-0.21849990739250558, 0.0, 0.0]

    # Properties modified on slice1.SliceType

    slice1.SliceType.Origin = [0.0, 0.0, 0.0]

    slice1.SliceType.Normal = [0.0, 0.0, 1.0]

    # show data in view

    slice1Display = Show(slice1, renderView1)

    # trace defaults for the display properties.

    slice1Display.ColorArrayName = ['POINTS', 'density']

    slice1Display.LookupTable = densityLUT

    slice1Display.GlyphType = 'Arrow'

    # hide data in view

    Hide(transientcase, renderView1)

    # show color bar/color legend

    slice1Display.SetScalarBarVisibility(renderView1, True)

    # set active source

    SetActiveSource(transientcase)

    # reset view to fit data

    renderView1.ResetCamera()

    # current camera placement for renderView1

    renderView1.CameraPosition = [-0.3656950276430585, -0.000908563692513454, 0.21027127790890924]

    renderView1.CameraFocalPoint = [-0.3656950276430585, -0.000908563692513454, 0.0]

    renderView1.CameraParallelScale = 0.25006857916835856

    # *****************

    # change legend layout, and its font color, position

    # *****************

    # get color legend for 'densityLUT' in view 'renderView1'

    densityLUTColorBar = GetScalarBar(densityLUT, renderView1)

    # Properties modified on densityLUTColorBar

    densityLUTColorBar.AutoOrient = 0

    densityLUTColorBar.RangeLabelFormat = '%.2f'

    ## legend orientation

    densityLUTColorBar.Orientation = 'Horizontal'

    ## legend normalized position

    densityLUTColorBar.Position = [0.3, 0.2]

    # change label color to 'black'

    densityLUTColorBar.LabelColor = [1.0, 1.0, 1.0] 

    #  change titile color to 'black'

    densityLUTColorBar.TitleColor = [1.0, 1.0, 1.0]

    # ***************

    # set Background color as 'White'

    renderView1.Background =[1,1,1]

    # get layout

    viewLayout1 = GetLayout()

    # save screenshot

    SaveScreenshot('/home/kaiming/Documents/ZJU_Projects/Jet/paraview/tem/d_%s.png' %(Num+1), layout=viewLayout1, magnification=1, quality=100)

    #################

    # pressure contour

    ##################

    # show color bar/color legend

    slice1Display.SetScalarBarVisibility(renderView1, False)

    # set active source

    SetActiveSource(slice1)

    # set scalar coloring

    ColorBy(slice1Display, ('POINTS', 'pressure'))

    # rescale color and/or opacity maps used to include current data range

    slice1Display.RescaleTransferFunctionToDataRange(True)

    # show color bar/color legend

    slice1Display.SetScalarBarVisibility(renderView1, True)

    # get color transfer function/color map for 'pressure'

    pressureLUT = GetColorTransferFunction('pressure')

    pressureLUT.LockDataRange = 1

    # get opacity transfer function/opacity map for 'pressure'

    pressurePWF = GetOpacityTransferFunction('pressure')

    # set active source

    SetActiveSource(transientcase)

    # *****************

    # change legend layout, and its font color, position

    # *****************

    # get color legend for 'pressureLUT' in view 'renderView1'

    pressureLUTColorBar = GetScalarBar(pressureLUT, renderView1)

    # Properties modified on vLUTColorBar

    pressureLUTColorBar.AutoOrient = 0

    pressureLUTColorBar.RangeLabelFormat = '%.2f'

    ## legend orientation

    pressureLUTColorBar.Orientation = 'Horizontal'

    ## legend normalized position

    pressureLUTColorBar.Position = [0.3, 0.2]

    # change label color to 'black'

    pressureLUTColorBar.LabelColor = [1.0, 1.0, 1.0] 

    #  change titile color to 'black'

    pressureLUTColorBar.TitleColor = [1.0, 1.0, 1.0]

    # ***************

    # current camera placement for renderView1

    # current camera placement for renderView1

    renderView1.CameraPosition = [-0.3656950276430585, -0.000908563692513454, 0.21027125790890924]

    renderView1.CameraFocalPoint = [-0.3656950276430585, -0.000908563692513454, 0.0]

    renderView1.CameraParallelScale = 0.25006857916835856

    # save screenshot

    SaveScreenshot('/home/kaiming/Documents/ZJU_Projects/Jet/paraview/tem/p_%s.png' %(Num+1), layout=viewLayout1, magnification=1, quality=100)

    ######################

    # #temperature contour

    ######################

    # show color bar/color legend

    slice1Display.SetScalarBarVisibility(renderView1, False)

    # set active source

    SetActiveSource(slice1)

    # set scalar coloring

    ColorBy(slice1Display, ('POINTS', 'temperature'))

    # rescale color and/or opacity maps used to include current data range

    slice1Display.RescaleTransferFunctionToDataRange(True)

    # show color bar/color legend

    slice1Display.SetScalarBarVisibility(renderView1, True)

    # get color transfer function/color map for 'termperature'

    temperatureLUT = GetColorTransferFunction('temperature')

    temperatureLUT.LockDataRange = 1

    # get opacity transfer function/opacity map for 'temperature'

    temperaturePWF = GetOpacityTransferFunction('temperature')

    # ******

    # legend layout, and its font color, position

    # *****

    temperatureLUTColorBar = GetScalarBar(temperatureLUT, renderView1)

    # Properties modified on vLUTColorBar

    temperatureLUTColorBar.AutoOrient = 0

    temperatureLUTColorBar.RangeLabelFormat = '%.2f'

    ## legend orientation

    temperatureLUTColorBar.Orientation = 'Horizontal'

    ## legend normalized position

    temperatureLUTColorBar.Position = [0.3, 0.2]

    # label color to 'black'

    temperatureLUTColorBar.LabelColor = [1.0, 1.0, 1.0] 

    #  change 'titile' color to 'black'

    temperatureLUTColorBar.TitleColor = [1.0, 1.0, 1.0]

    # *****************

    # set active source

    SetActiveSource(transientcase)

    # current camera placement for renderView1

    # current camera placement for renderView1

    renderView1.CameraPosition = [-0.3656950276430585, -0.000908563692513454, 0.21027127790890924]

    renderView1.CameraFocalPoint = [-0.3656950276430585, -0.000908563692513454, 0.0]

    renderView1.CameraParallelScale = 0.25006857917835856

    # save screenshot

    SaveScreenshot('/home/kaiming/Documents/ZJU_Projects/Jet/paraview/tem/t_%s.png' %(Num+1), layout=viewLayout1, magnification=1, quality=100)

    # *****************

    #  Velocity

    # ****************

    # show color legend

    slice1Display.SetScalarBarVisibility(renderView1, False)

    # set active source

    SetActiveSource(slice1)

    # set scalar coloring

    ColorBy(slice1Display, ('POINTS', 'v'))

    # rescale color and/or opacity maps used to include current data range

    slice1Display.RescaleTransferFunctionToDataRange(True)

    # show color bar/color legend

    slice1Display.SetScalarBarVisibility(renderView1, True)

    # get color transfer function/color map for 'v'

    vLUT = GetColorTransferFunction('v')

    vLUT.LockDataRange = 1

    # get opacity transfer function/opacity map for 'v'

    vPWF = GetOpacityTransferFunction('v')

    # *****************

    # change legend layout, and its font color, position

    # *****************

    # get color legend for 'densityLUT' in view 'renderView1'

    vLUTColorBar = GetScalarBar(vLUT, renderView1)

    # Properties modified on vLUTColorBar

    vLUTColorBar.AutoOrient = 0

    vLUTColorBar.RangeLabelFormat = '%.2f'

    ## legend orientation

    vLUTColorBar.Orientation = 'Horizontal'

    ## legend normalized position

    vLUTColorBar.Position = [0.3, 0.2]

    # change label color to 'black'

    vLUTColorBar.LabelColor = [1.0, 1.0, 1.0] 

    #  change titile color to 'black'

    vLUTColorBar.TitleColor = [1.0, 1.0, 1.0]

    # ***************

    # set active source

    SetActiveSource(transientcase)

    # current camera placement for renderView1

    # current camera placement for renderView1

    renderView1.CameraPosition = [-0.3656950276430585, -0.000908563692513454, 0.21027125790890924]

    renderView1.CameraFocalPoint = [-0.3656950276430585, -0.000908563692513454, 0.0]

    renderView1.CameraParallelScale = 0.25006857916835856

    # save screenshot

    SaveScreenshot('/home/kaiming/Documents/ZJU_Projects/Jet/paraview/tem/v_%s.png' %(Num+1), layout=viewLayout1, magnification=1, quality=100)

    #### saving camera placements for all active views

    # current camera placement for renderView1

    # current camera placement for renderView1

    renderView1.CameraPosition = [-0.3656950276430585, -0.000908563692513454, 0.21027127790890924]

    renderView1.CameraFocalPoint = [-0.3656950276430585, -0.000908563692513454, 0.0]

    renderView1.CameraParallelScale = 0.25006857916835856

    #### uncomment the following to render all views

    # RenderAllViews()

    # alternatively, if you want to write images, you can use SaveScreenshot(...).

11 theory

jet_theory.html

12 Video

12.1 Ignition of a turbulent methane jet

(fuel=70% CH4 and 30% air in volume), ignited by an electrical spark (100mJ, 400 micro-second, electrode gap: 1mm). Isosurface of equivalence ratio = 1 (blue) and of mass fraction of H2O (Y=0.5) colored by the temperature. Author: G. Lacaze Credit: CERFACS

13 Reference

13.1 contacts

chia fon lee uiuc

14 reseach groups

Turbulence and Combustion Group, Cornell Uni. College of Engineering,

15 How to

3D video
Q-criteria

15.1 3D video

software: Paraview

15.1.1 steps

record all commands

tool/start traces

References: exercise 3.1 creating a Python script trace, tutorial guide
get an image
a. slip the Computational domain b. change background to white

c. save an image

Reference:

export vector graphics

get multiple images with Python scripts

60 time steps

image >> video

15.1.2 Reference video

Bryn Noel Ubald- An instrumented turbine blade – Another unique perspective https://www.youtube.com/watch?v=JKJnkYFyskw&index=7&list=PLpzImLbDbsyCrFS2fXlyaiFXb87JdZpm-&pbjreload=10

15.1.3 change contour variable

#### import the simple module from the paraview from paraview.simple import * #### disable automatic camera reset on 'Show' paraview.simple._{DisableFirstRenderCameraReset}()

transientcase = EnSightReader(CaseFileName='/home/kaiming/Documents/ZJU_Projects/Jet/data/transient.case') transientcase.PointArrays = ['density', 'v', 'pressure', 'temperature']

renderView1 = GetActiveViewOrCreate('RenderView')

densityLUT = GetColorTransferFunction('density')

transientcaseDisplay = Show(transientcase, renderView1)

transientcaseDisplay.ColorArrayName = ['POINTS', 'density'] transientcaseDisplay.LookupTable = densityLUT transientcaseDisplay.GlyphType = 'Arrow' transientcaseDisplay.ScalarOpacityUnitDistance = 0.0016420380639339577

renderView1.ResetCamera()

transientcaseDisplay.SetScalarBarVisibility(renderView1, True)

densityPWF = GetOpacityTransferFunction('density')

ColorBy(transientcaseDisplay, ('POINTS', 'v'))

transientcaseDisplay.RescaleTransferFunctionToDataRange(True)

transientcaseDisplay.SetScalarBarVisibility(renderView1, True)

vLUT = GetColorTransferFunction('v')

vPWF = GetOpacityTransferFunction('v')

#### saving camera placements for all active views

renderView1.CameraPosition = [-0.21849990739250558, 0.0, 0.9661907958485202] renderView1.CameraFocalPoint = [-0.21849990739250558, 0.0, 0.0] renderView1.CameraParallelScale = 0.25006857916835856

change contour variable from 'density' to 'v'

ColorBy(slice1Display, ('POINTS', 'v'))

slice1Display.RescaleTransferFunctionToDataRange(True)

slice1Display.SetScalarBarVisibility(renderView1, True)

vLUT = GetColorTransferFunction('v')

vPWF = GetOpacityTransferFunction('v')

#### saving camera placements for all active views

renderView1.CameraPosition = [-0.24175098022185249, 0.11823180090490217, 1.098500283147858]
renderView1.CameraFocalPoint = [-0.20832480931184155, 0.12646538877612318, 0.00125895591456612]
renderView1.CameraViewUp = [8.169175204111794e-05, 0.9999718249271369, 0.007506176013726962]
renderView1.CameraParallelScale = 0.23481544622305758

#### uncomment the following to render all views

16 Results

inlet pressure, T, density, ρ

3D video similar to
Q-criteria
Turbulent BL, shear layer

17 Script FAQ

17.1 camera placement

renderView1.CameraPosition = [-0.22126314316421933, 0.12646846135388234, 1.0978252757245606]
renderView1.CameraFocalPoint = [-0.2082859046961596, 0.12646846135388234, 0.00012075157365905824]
renderView1.CameraParallelScale = 0.23481544622305758

left figure:

renderView1.CameraPosition = [-0.21849990739250558, 0.0, 2.0711157783058827 ]

Right figure:

renderView1.CameraPosition = [-0.21849990739250558, 0.0, 1.1690908629767092 ]

as seen in the above figure, the smaller is z value , the bigger is the figure

17.2 To load the EnSight files using the `transient.case` script

## create a new 'EnSight Reader'

    transientcase = EnSightReader(CaseFileName='/home/kaiming/Documents/ZJU_Projects/Jet/transient.case')

    transientcase.PointArrays = ['density', 'v', 'pressure', 'temperature']

#### import the simple module from the paraview from paraview.simple import * #### disable automatic camera reset on 'Show' paraview.simple._{DisableFirstRenderCameraReset}()

transientcase = EnSightReader(CaseFileName='/home/kaiming/Documents/ZJU_Projects/Jet/data/transient.case') transientcase.PointArrays = ['v', 'density', 'pressure', 'temperature']

renderView1 = GetActiveViewOrCreate('RenderView')

densityLUT = GetColorTransferFunction('density')

transientcaseDisplay = Show(transientcase, renderView1)

renderView1.ResetCamera()

transientcaseDisplay.SetScalarBarVisibility(renderView1, True)

densityPWF = GetOpacityTransferFunction('density')

#### saving camera placements for all active views

renderView1.CameraPosition = [-0.21849990739250558, 0.0, 0.9661907958485202] renderView1.CameraFocalPoint = [-0.21849990739250558, 0.0, 0.0] renderView1.CameraParallelScale = 0.25006857916835856

#### uncomment the following to render all views

#+END_SRC

17.3 NameError: name 'slice1Display_1' is not defined

Traceback (most recent call last):

solution:

assign active view to renderView1

renderView1 = GetActiveViewOrCreate('RenderView')

17.4 View

renderView1 = GetActiveViewOrCreate('RenderView')

renderView1.Background =[1,1,1]

renderView1.ViewSize = [1920, 1080]

17.5 Save screenshot

Version 1

SaveScreenshot('/home/kaiming/Documents/ZJU_Projects/Jet/paraview/jet₆₄.png', view=renderView1, ImageResolution=[1920,1080])

Version 2

SaveScreenshot('/home/kaiming/Documents/ZJU_Projects/Jet/paraview/jet₁.png', magnification=1, quality=100, view=renderView1)

exercise, 2.25 tutorial, V5.6

https://forgeanalytics.io/blog/saving-a-screenshot-in-paraview/ https://www.paraview.org/Wiki/ParaView/Python/Screenshot

17.6 legend

Footnotes:

DEFINITION NOT FOUND.

Author: kemina

Created: 2019-03-20 Wed 11:07

Emacs 24.5.1 (Org mode 8.2.10)

Validate

巴特西

jet flow in a combustion chamber

Table of Contents

1 contacts

2 Paper digest

2.1 LES vs. RANS

2.2 Dynamics of Transient Fuel Injection, Mixing, and Auto-Ignition

2.3 rothamer research group, Experimental Studies of Transient Jets

2.4 the transient start of supersonic jets

2.5 decelerating transient turbulent jets

2.5.1 Bing huan, 2012, physics of fluids

2.6 validi 2016, PhD thesis, Michigan State University

2.7 P wang, 2008,

2.8 TJI assited combustion system 2016

3 TODO Purpose of study

4 TODO Questions

5 FAQ

5.1 is it a spark ignition (gasoline)?

5.2 time step size in your LES ?

5.3 When does the main chamber start to burn/combust?

5.4 how to estimate the Mach number

5.5 mixture fraction calculation

6 problem description

7 results

7.1 mixture fraction – defining the jet boundary

8 setups

9 source files

9.1 transient.case

10 Post-processing

10.1 plot axial streamwise velocity–paraview

10.1.1 script

10.2 axial velocity along centerline (Jet) – Matlab

10.2.1 scpirts

10.2.2 log

10.3 Q-criterion

10.3.1 scripts

10.4 video of velocity contour

10.4.1 fixed label value

10.4.2 Python file I/O

10.4.3 loop in python

10.5 multiple slides with for loop

11 theory

12 Video

12.1 Ignition of a turbulent methane jet

13 Reference

13.1 contacts

14 reseach groups

15 How to

15.1 3D video

15.1.1 steps

15.1.2 Reference video

15.1.3 change contour variable

16 Results

17 Script FAQ

17.1 camera placement

17.2 To load the EnSight files using the transient.case script

17.3 NameError: name 'slice1Display1' is not defined

17.4 View

17.5 Save screenshot

17.6 legend

Footnotes:

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17.2 To load the EnSight files using the `transient.case` script

17.3 NameError: name 'slice1Display_1' is not defined