Abstract: This database provides the datapoints for the publication "von Deyn, L. H., Gatti, D., & Frohnapfel, B. (2022). From drag-reducing riblets to drag-increasing ridges. Journal of Fluid Mechanics, 951, A16. Cambridge University Press".
TechnicalRemarks: --------------------------------------------------------------------------------
Database: From Drag-Reducing Riblets to Drag-Increasing Ridges
This database provides the measurement data presented in the journal article
"From drag reducing riblets to drag increasing ridges" (doi:10.1017/jfm.2022.796).
It features high-precision pressure measurements in a wind tunnel facility along the test section
and the corresponding flow rate used to determine the skin friction drag change of ribelts and ridges.
Datapoints for eight geometrically different sets of 2D trapezoidal groove geometries are included.
Different orifice diameters are used to cover the bulk Reynolds number range $4500<Re_b<85000$ as specified in table 1.
The introduced index is used in the data files to mark the different orifices.
Table 2 provides the physical dimensions of the investigated geometries.
For more details refer to the journal article, figure 2 and table 2.
table 1:
|type | index | diameter | range in Re_b
|----------------|:-------------------------------:|:-----------------------------:|:------------------:
|orifice|1 |60[mm] |4500<Reb<13000
|orifice|2 |105[mm] |6000<Reb<23000
|orifice|3 |120[mm] |7000<Reb<38000
|orifice|4 |150[mm] |30000<Reb<85000
_____s_____
/\ /\ |
/ \ / \ |h
__/ \ ___ / \ ____
--sr--
table 2:
|ID | s[mm] | h[mm] | s/sr | tip angle
|----------------|:----:|:-----:|:----:|:-----:
|dr_1a|0.086 |0.09 |1 |51.1
|dr_1b|0.17 |0.18 |1 |50.6
|dr_1c|1 |0.87 |1 |60
|dr_2|0.614 |0.294 |2.07 |53.5
|di_2|5.31 |2 |2.3 |60
|di_4|9.23 |2 |4 |60
|di_8|18.48 |2 |8 |60
|di_13|27.31 |2 |13.2 |54.8
Content:
*readme.txt
*dr_xx: four geometrically different sets of riblets measured in the range of 4500<Reb<85000.
*di_xx: four geometrically different sets of ridges measured in the range of 4500<Reb<89000.
