LDA-Messdaten: Strömung über die zurückspringende Stufe - Variation des Stufenwinkels.

*******************************************************************************************

Authors:                  B. Ruck und B. Makiola    
Address:         
        Institute for Hydromechanics
                              University of Karlsruhe     
                              Kaiserstr. 12               
                              76128 Karlsruhe
                             
Germany  
                             
Tel.: (0721) 608-43897
                              e-mail: ruck@kit.edu               

Project:   Ru 345/6 
Schwerpunktsförderung   "Physik abgelöster Strömungen", Februar 1992
Basisveröffentlichungen:

Ruck, B., Makiola, B.,1993: "The Flow over the Inclined Step", Notes on Numerical Fluid Mechanics, (Hrsg. Gersten), Vieweg-Verlag, Volume 40, pp. 47-55
Makiola, B., Ruck, B., 1993: "Flow Separation Over the Step with Inclined Walls, Near Wall Turbulent Flows, Launder, B.E., Speziale, C.G. (Eds.), Elsevier Press

Veröffentlichung auszugsweise mit Quellennachweis erlaubt.

Data for expansion ratio 1.48 

Data for expansion ratio 2.00

 

Data for expansion ratio 3.27


------------------------------------------------------------------------------ 

 

Erläuterung zum Lesen der Daten:

 

In this file you get the information about the file handling for the data files,

containing velocity data from LDA measurements behind a backward-facing step

flow with inclined step geometries.

 

 

Sketch of the investigated flow geometry:

 

                   y/H

                   |

                   |

                   |

==================================================================

Uo = max. inlet    |

     velocity      |

--> flow direction |

                   |

h1 = inlet height  |

====================\

                   |  \

                   |    \

                   |      \

 H = step height   |        \

                   |          \

                   | step       \

                   | angle  alpha \        h2 = height behind the step

================================================================-----> x/H

 negative <------| 0 |-----> positive

 

 

File name:

 

          files with the extension *.mak are data files in which all measured

          results for one step geometry and one Reynolds number are stored.

 

 

File-name-structure:

 

           example:             m15all.mak

 

           The first letter "m" indicates the investigated step angle  and

           the expansion ratio ER according to the following table 1.

 

           The number "15" indicates the Reynolds number divided by 1000

 

           "all" indicates that the whole data set is complete

 

 

Table 1:

=====================================

|alpha |  ER=1,48 | ER=2,0 |ER=3,27 |

=====================================

| 90   |   M      |  O     |  Y     |

|-----------------------------------|

| 45   |   N      |  B     |  --    |

|-----------------------------------|

| 30   |   H      |  P     |  --    |

|-----------------------------------|

| 25   |   J      |  L     |  F     |

|-----------------------------------|

| 20   |   I      |  U     |  X     |

|-----------------------------------|

| 15   |   G      |  V     |  Z     |

|-----------------------------------|

| 10   |   K      |  R     |  --    |

=====================================

 

 

Streamwise velocity data for the following ("x") flow conditions

are available:

 

Table 2:

============================================================================

| Expansion |angle  |        Reynolds number (based on Uo and h1)          |

| ratio ER  |alpha  |  5000 | 8000 | 11000 | 15000 | 33000 | 47000 | 64000 |

============================================================================

|       (M )| 90    |  x    | x    | x     | x     | -     | x     | x     |

|       (N )| 45    |  x    | -    | -     | x     | -     | x     | -     |

|       (H )| 30    |  x    | x    | x     | x     | -     | x     | -     |

| 1.48  (J )| 25    |  x    | x    | x     | x     | -     | x     | x     |

|       (I )| 20    |  x    | x    | x     | x     | -     | x     | x     |

|       (G )| 15    |  x    | x    | x     | x     | -     | x     | x     |

|       (K )| 10    |  x    | x    | x     | x     | -     | x     | x     |

============================================================================

|       (O )| 90    |  -    | -    | -     | x     | x     | x     | x     |

|       (B )| 45    |  -    | -    | -     | x     | x     | x     | x     |

|       (P )| 30    |  -    | -    | -     | x     | x     | x     | -     |

| 2.00  (L )| 25    |  -    | -    | -     | x     | -     | x     | x     |

|       (U )| 20    |  -    | -    | -     | x     | -     | x     | x     |

|       (V )| 15    |  -    | -    | -     | x     | -     | x     | x     |

|       (R )| 10    |  -    | -    | -     | x     | -     | x     | x     |

===========================================================================|

|       (Y )| 90    |  x    | x    | x     | x     | -     | -     | -     |

| 3.27  (F )| 25    |  x    | x    | x     | x     | -     | -     | -     |

|       (X )| 20    |  x    | x    | x     | x     | -     | -     | -     |

|       (Z )| 15    |  x    | x    | x     | x     | -     | -     | -     |

===========================================================================|

 

 

Data-file-structure:

 

All data files ***.mak have a header, in which all important  information

is stored. In the following example the header and the data-structure

are explained.

 

 

 m15all.mak       = Filename    <--- file name

 15000.           = Reynolds-Zahl <--- Reynolds number based on max.

                                  inlet velocity and inlet channel height

  1.48            = Expansionsverhaeltnis ER  <--- expansion ratio ER = h2/h1

 12.00            = Stufenhoehe [mm]   <--- step height H in mm

 90.00            = Stufenwinkel   <--- step angle alpha

  8.69            = Uo [x/H=-2] Bezugsgeschwindigkeit <-- max. inlet velocity 

                                  2 step heights before the step edge in m/s

  6.35            = Wiederanlegelaenge gemessen <--- measured reattachment

                                       length, normalized with step height H

  x/H    y/H     U/Uo   rms/Uo  psinorm   <--- column  indicator

 ----------------------------------------------------------------------------

 -2.00   1.000    .000    .000   .0000

 -2.00   1.042    .339    .136   .0041

 -2.00   1.083    .595    .139   .0154

 -2.00   1.167    .738    .113   .0476

 -2.00   1.292    .837    .094   .1046

 -2.00   1.417    .877    .087   .1668

 -2.00   1.625    .934    .077   .2762

 -2.00   1.833    .972    .056   .3914

 -2.00   2.042   1.000    .053   .5105

 -2.00   2.250    .978    .040   .6300

 -2.00   2.458    .918    .061   .7446

 -2.00   2.667    .846    .081   .8512

 -2.00   2.792    .795    .081   .9106

 -2.00   2.917    .716    .096   .9654

 -2.00   3.083    .000    .000  1.0000

   .00   1.000    .000    .000   .0000

   .00   1.042    .185    .139   .0022

   .00   1.083    .588    .142   .0116

   .00   1.167    .739    .100   .0439

   .00   1.292    .807    .084   .1002

   .00   1.417    .871    .086   .1614

   .00   1.625    .931    .070   .2708

   .00   1.833    .978    .058   .3868

...

 

1. column (x/H): with the step height normalized streamwise channel

                  coordinate

 

2. column (y/H): with the step height normalized channel height

 

3. column (U/Uo): mean streamwise velocity (U), normalized with the max.

                  inlet velocity (Uo)

 

4. column (rms/Uo): rms-velocity (u'), normalized with the max. inlet

                    velocity (Uo)

 

5. column (psinorm): calculated values for the normalized stream function

 

 

 

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